Cardiology Flashcards

Question

- Situational syncope (eg due to micturition, defecation, or sight of blood) - Can be elicited by noxious stimuli, pain, emotion, prolonged standing, or sudden position change from lying or sitting to standing. - Hair grooming syncope may be related to vasovagal syncope, and increasing fluids and salt intake may help prevent episodes.

Answer 1

- Situational syncope (eg due to micturition, defecation, or sight of blood) - Can be elicited by noxious stimuli, pain, emotion, prolonged standing, or sudden position change from lying or sitting to standing. - Hair grooming syncope may be related to vasovagal syncope, and increasing fluids and salt intake may help prevent episodes.

Answer 2

- Orthostatic Hypotension - Typically occurring with prolonged standing in a warm environment or on quickly arising from a supine to standing position. - POTS (Postural Orthostatic Tachycardia Syndrome) is a related disorder in which tachycardia is the dominant finding.

Answer 3

- Cardiogenic syncope - Important findings include systolic ejection murmur (AS, HCM), preceding chest pain or palpitations, and symptoms with exercise. - Any patient who has syncope with exercise requires a cardiac evaluation bc vagal tone is reduced during exercise. - If suspect arrhythmia, order a 24-hr Holter and EKG (Note; An EKG is probably the best test to order in a pt with recurrent, unexplained syncope!) - EKG will assess for a prolonged QT interval or WQW, and may find signs of ischemia.

Answer 4

INFECTIVE ENDOCARDITIS - Primary endocarditis - Infection of native heart tissue - Secondary endocarditis - Infection of prosthetic material - Occurs most often in children with underlying congenital heart disease (92% of endocarditis have underlying heart defect, congenital or rheumatic) - Path: - Viridans streptococci (Streptococcus mitis) (40%) and Staph aureus (20-30%) are the most common organisms responsible for IE in pediatric patients with or without congenital heart disease. - Staph aureus is the more likely pathogen in an otherwise structurally normal heart - Streptococcus mitis is more often associated with abnormal cardiac valves (congenital heart disease, rheumatic heart disease, postoperative changes) - HAACEK organisms. These are often responsible for “culture-negative” endocarditis bc they can require >7 days to grow to detectable levels in culture media - Haemophilus species - Aggregatibacter parainfluenzae - Aggregatibacter actinomycetemcomitans - Cardiobacterium hominis - Eikenella corrodens - Kingella species - In prosthetic valve endocarditis (PVE), occurring up to 1 year after surgery, by far the most common organism is Staph epidermidis (55-60%) - If IV drug addicts: S aureus (50%), enterococci (15%), streptococci (20%), pseudomonas and serratia (10%), Candida (5%) - Pt: - The clinical presentation of infective endocarditis can be subacute or acute and is often nonspecific. - Subacute, over several weeks, with more indolent often prolonged course of fever and nonspecific symptoms such as malaise, arthralgias, weight loss, and diaphoresis - OR Acute, rapidly progressive - Presents differently in children than in adults/adolescents: - ABE: Janeway lesions (small painless hemorrhagic lesions on the palms and soles resulting from embolization of heart vegetations) - SBE: Children only rarely have Roth spots (small retinal hemorrhages), Osler nodes (small tender intradermal nodules on the fingers, palms, and soles/toes), conjunctival hemorrhages, heart murmurs, and splinter hemorrhages (linear streaks beneath the nail beds) - Osler nodes and Roth spots are late developments of SBE and are seen less frequently today bc SBE is diagnosed tx earlier. - Duke criteria - 3 major criteria - 1. Blood culture positive for infective endocarditis (blood culture is positive in >95% of pediatric cases) - 2 positive separate blood cultures with typical pathogens consistent with IE - OR Persistently positive blood cultures with microorganisms consistent with IE - At least 2 positive cultures of blood drawn >12 hours apart - Or all of 3 or a majority of >4 separate cultures of blood - OR Single positive blood culture with Coxiella burnetii or antiphase I IgG antibody titer >1:800 - 2. New findings on echocardiogram consistent with endocarditis - Oscillating intracardiac mass on valve or supporting structures, in the path of regurgitant jets, or on implanted material - New valve regurgitation - Abscess or vegetations - New partial dehiscence of prosthetic valves - 3. New murmur consistent with valve regurgitation - Minor criteria - 1. Underlying heart disease or IV drug abuse - 2. Fever >38C - 3. Microbiologic evidence: Positive blood cultures but does not meet major criteria or serologic evidence of active infection with organisms consistent with IE - 4. Vascular phenomenon: Evidence of vasculitis, major arterial emboli, septic pulmonary infarcts, mycotic aneurysms, intracranial hemorrhage, conjunctival hemorrhages, Janeway lesions - 5. Immunologic phenomena: Glomerulonephritis, Osler’s nodes, Roth’s spots, and positive rheumatoid factor - Work-up - 2 Blood cultures obtained separately - Echocardiography is needed - to evaluate valves for lesions, such as vegetations or abscesses - Dx: - Definitive infective endocarditis when patient has any of the following: - Pathologic criteria - Microorganisms demonstrated by culture or histologic exam of a vegetation, a vegetation that has embolized, or an intracardiac abscess specimen - OR Pathologic lesions; vegetation or intracardiac abscess confirmed by histologic exam showing active endocarditis - Clinical criteria: - 2 major criteria OR - 1 major and 3 minor criteria OR - 5 minor criteria - Possible infective endocarditis - 1 major criterion and 1 minor criterion OR 3 minor criteria - Tx: - Prolonged course of appropriate IV antibiotics for 4-8 weeks - Tx of native valve endocarditis - Streptococci (viridans streptococci and S bovis) - PCN-sensitive streptococci: 4 weeks of PCN G or ceftriaxone - PCN-insensitive streptococci: 4 weeks of PCN G (at higher dose than used in PCN-sensitive) or ceftriaxone - MRSA: Vancomycin for 6 weeks. - Enterococci: Ampicillin/PCN G + gentamicin for 4-6 weeks - HACEK: Ceftriaxone, ampicillin (if susceptible), or ciprofloxacin for 4 weeks - Tx of prosthetic valve endocarditis - Strep/enterococci: Same for >6 weeks - Staph: Nafcillin (>6 weeks)+ rifampin (>6 weeks) + gentamicin (2 weeks) - HACEK: Ceftriaxone, ampicillin (if susceptible), or ciprofloxacin x4 weeks

Answer 5

Infective Endocarditis Prophylaxis prior to dental procedures - Prophylaxis is recommended in patients who have - Prosthetic cardiac valves or prosthetic material used for cardiac valve repair - Hx of infective endocarditis - Undergone cardiac transplant who develop cardiac valvuloplasty - Unrepaired cyanotic congenital heart disease (including patients with palliative shunts and conduits) - Repaired cyanotic congenital heart disease with prosthetic material/device during the 1st 6 months after the procedure (as endothelialization of the prosthetic material occurs within 6mo after procedure and will not be reliably completed) or residual defects (such as residual shunt, persistent leak, abnormal flow) - Antibiotic prophylaxis is not recommended for any other form of congenital heart disease, for GU or GI procedures (or acquired valve disease, HCM, or bicuspid aortic valve).

Answer 6

Prophylactic regimens - Standard general prophylaxis - Amoxicillin 50 mg/kg (max 2g) PO 1 hour before procedure - Unable to take oral medications - Ampicillin 50 mg/kg (max 2g) IM/IV within 30 min before procedure - Allergic to penicillin - Clindamycin 20mg/kg (max 600mg) PO 1 hour before procedure - Or Cephalexin or cefadroxil 50mg/kg (max 2g) 1 hour before procedure - Cephalosporins are not used if PCN allergy is an immediate-type hypersensitivity reaction - Or Azithromycin or clarithromycin 15mg/kg (max 500mg) PO 1 hour before procedure - Both allergic to penicillin and unable to take oral meds - Clindamycin 20mg/kg (max 600mg) IV within 30 min before procedure - Or Cefazolin 25mg/kg IM/IV (max 1g) within 30 min before procedure. - PO doses are given 1 hour before surgery whereas IM/IV doses are given within 30 min If the pt is already on chronic amoxicillin/penicillin, prescribe the ppx abx from a different class

Answer 7

CARDIOMYOPATHY - 3 main types: Dilates, hypertrophic, and restrictive. - If diagnosed in a young child (<4yo), it is important to screen for metabolic disorders. - If there is a 1st degree family hx of cardiomyopathy or sudden death at an early age, screen family members for cardiomyopathy with genetic testing, EKG, and/or echo.

Answer 8

Hypertrophic Cardiomyopathy - Is the most common cause of sudden death on the athletic field in the US - AD disorder with variable expression. - 50% of the mutations occur on chromosome 14. - Are at risk of death from arrhythmias. HCM (with or without obstruction) is the most common cardiac cause of sudden death in young athletes at sporting events in the US - Murmur is delayed in onset - a Grade 3-4/6 crescendo-decrescendo systolic murmur at the middle L to upper R sternal border. - Murmur gets louder with Valsalva or rising to an erect position. Either of these reduces venous return, resulting in a decrease in LV volume and an increase in the effect of the obstruction. - If you have the child squat, venous return increases and decreases the murmur due to LV dilatation. - Look for a child in whom the murmur gets softer with squatting. It is HCM, not AS! - Note: These same maneuvers produce the opposite effects in AS. - Screening EKG shows common findings of LVH, prominent septal Q waves, and abnormal repolarization or strain (look for negative T waves in V6). L axis deviation, ST-T wave abnormalities, conduction abnormalities and/or pathological Q waves. - Dx: Echo showing abnormal LVH without other cause - Management - Beta-blockers are the mainstay of therapy. - Children who have symptoms of syncope, aborted sudden death, arrhythmias, or severe thickening of their interventricular septum requires placement of an implantable cardioverter-defibrillator and/or surgical therapy (myectomy) to remove part of the thickened myocardial tissue (typically from the interventricular septum).

Answer 9

Athlete’s Heart - Path: Physiologic condition characterized by increased LV wall thickness in response to intense cardiovascular training. - EKG for LV hypertrophy: high-voltage QRS complexes and lateral repolarization abnormalities (inverted T waves) - However, hypertrophic cardiomyopathy is the most common cause of sudden cardiac death and causes similar findings on EKG. A young athletes with EKG findings of LVH and unexplained symptoms (chest pain, palpitations, presyncope, syncope) should be evaluated for HCM or other structure heart disease with TRANSTHORACIC ECHOCARDIOGRAPHY.

Answer 10

Hypertrophic cardiomyopathy vs Athlete’s heart - HCM - Left ventricular wall thickness >15mm - Positive family hx of HCM - EKG: Prominent Q waves; LVH criteria - Left atrial size enlarged - Small or normal LV cavity - Abnormal LV diastolic function - Athlete’s heart - Left ventricular wall thickness <15mm - No family hx - EKG: No Q waves; LVH criteria - Dilated LV cavity - Normal LV diastolic function

Answer 11

Takotsubo Cardiomyopathy - Pt: Chest pain, dyspnea, positive troponin in 95% cases - Absence of coronary artery disease or angiographic evidence of plaque rupture

Answer 12

Acute pericarditis - Path: - Most common cause is idiopathic or viral (eg coxsackie A and B, echovirus, adenovirus) - Pt: - Pain is often relieved by leaning forward and sitting upright. Exacerbated by lying supine and inspiration or cough. - Pericardial friction rub is pathognomonic but not found in every patient. It is a scratchy, high-pitched, to-and-fro sound caused by pericardial surfaces rubbing together. - EKG: Diffuse ST segment elevations with associated PR segment depression (esp V6 and V6) - Echo is performed to help distinguish pericarditis from myocarditis. Echo can have normal findings or demonstrate pericardial effusion. - Tx: - Often a benign condition and chest pain and inflammation be treated with anti-inflammatory medications NSAIDs.

Answer 13

Pericardial Effusion - Can be caused by pericarditis. - Characterized as serous, purulent, or bloody. - Pt: Positional chest pain and may produce a friction rub caused by pericardial inflammation - If the effusion is large, the heart sounds become muffled. - EKG may demonstrate low-voltage QRS complexes, sinus tachycardia, and electrical alternans. - Diffusely low voltages on EKG is a non-specific sign that generally suggests that there is distance between the heart and the EKG leads. - CXR may show cardiomegaly / enlarged cardiac silhouette (water-bottle heart) in case of large pericardial effusion - Tx: Same as mentioned for acute pericarditis

Answer 14

Cardiac Tamponade - Pt: - Kussmaul sign (more commonly seen in constrictive pericarditis). - Remember: Normally with inspiration the pressure in the intrathoracic cavity drops and abdominal pressure increases, so that systemic venous return increases. With tamponade, the increase in venous return cannot be accomodated. This cause the jugular venous pressure to rise with inspiration, known as Kussmaul sign - Pulsus paradoxus (variation of BP with breathing) - Remember: Normally with inspiration, aortic BP can fall 4-10mmHg. With tamponade, the aortic pressure falls >10-15mmHg, resulting in pulsus paradoxus. - Beck triad: 3 findings: Rising JVP, dropping systolic BPs, muffled heart sounds - Classic question gives diastolic pressure readings in the 4 chambers of the heart that are all the same. This occurs in either tamponade or constrictive pericarditis - Tx: - IVFs should always be bolused aggressively in suspected tamponade prior to pericardiocentesis to improve preload. - Immediately remove fluid via pericardiocentesis

Answer 15

Constrictive Pericarditis - Kussmaul sign occurs frequently, and pulsus paradoxus can also be present. End-diastolic pressures in all 4 chambers are equal. - Tx by removing the restrictive fibrous tissue.

Answer 16

Postpericardiotomy syndrome - Can follow any surgery in which the pericardium is disturbed or opened but is most commonly seen following surgical ASD repair. - Most attacks happen 1-4 weeks postsurgery, but they can occur as far out as 6 months. - Pt: Acute pericarditis, pericardial effusion, and fever. - Tx: Aspirin 80-100 mg/kg/day.

Answer 17

HEART FAILURE - Cardiogenic shock from ductal dependent lesion should be at the top of the differential for any infant presenting in shock in the first 2-3 weeks of life. - While orthopnea is commonly seen in adults, it is rarely seen in children. - Management: - Most important aspect of tx is patency of the PDA, which is achieved with empiric prostaglandin E-1 (PGE1) infusion to keep the ductus open. - Side effect of prostaglandin is apnea

Answer 18

CHF - Path: - ADH release is increased, which decreases the excretion of water in the distal nephron, resulting in hyponatremia - Infants - Heart failure presents as feeding difficulties, distress with eating, or refusal to eat. - Infants and young children often present with FTT and can also have respiratory symptoms such as tachypnea, retractions, and grunting. - Pt: - Infant - poor growth, tachypnea, poor feeding, sweating with feeding, fatigue, and irritability - Young children - fatigue, abdominal pain due to ascites, nausea/vomiting, failure to thrive, and cough with wheezing - Older children - exercise intolerance, SOB, decreased appetite, cough with wheezing, edema, palpitations, syncope, and chest pain - Physical exam: - Typically present with poor growth, tachypnea, tachycardia, and difficulty with activity. - Timing of presentation of heart failure is also helpful in determining the cause: - 1st week of life - Left heart obstruction (eg critical coarctation, hypoplastic L heart syndrome) - 4-8 weeks of life - Left-to-right shunt (VSD, AVSD) - 6-8 years of life - Acquired heart disease (eg rheumatic fever, myocarditis) - Evaluation - EKG - An infant with CHF and EKG with deep Q waves in the inferior leads (II, III, AVF) should be evaluated for an anomalous left coronary artery from the pulmonary artery (ALCAPA). - Echocardiography to assess myocardial function and to evaluate for structural cardiac defects. - BNP (hormone secreted by heart to help regulate BP) and pro-BNP are elevated in pts with HF. These levels can be a helpful screening tool. - Elevated serum BNP levels indicate that dyspnea is due to pulmonary congestion caused by cardiac failure. - BNP levels are not elevated when dyspnea is caused by lung disease.

Answer 19

CHF Management - Management - Tx: Depends on the cause and must be tailored specifically for each case. - Diuretics and afterload reducers (ace inhibitors) - Increasing the caloric density of feeds is often the 1st step in managing infants with growth failure related to heart failure. - The recommended intake goal for infants with CHF is 140 kcal/kg/day. - Goals of pharmacologic therapy include preload reduction, contractility enhancement, and afterload reduction. - *Preload reduction (Diuretics): Principal agents for control of pulmonary as well as systemic venous congestion. - Loop diuretics: Furosemide and bumetanide - Loop diuretics are often the 1st medication added to management of pediatric heart failure. - Side effects: Hypokalemia, hypochloremia, hyponatremia, metabolic alkalosis - Agents that affect cortical diluting segment: Thiazide, metolazone - Thiazides increase K loss and decrease Ca excretion - Potassium-sparing diuretics: Spironolactone - Monitor pts for hyperkalemia, esp if supplementing potassium or using an ACE-i. - A much less common side effects (but one that shows up on exams!) is gynecomastia developing from the neurohormonal interactions. - *Contractility enhancement (Inotropic agents):Improve contractility of the heart. Goal is to increase cardiac output and improve perfusion to vital organs and tissues. - Dopamine - Dobutamine - Epinephrine - Milrinone - Digoxin (Digitalis glycosides) - Toxicity: - Acute digoxin toxicity typically presents with nausea, vomiting, and diarrhea. - Be esp aware of color-vision changes, confusion, or vertigo. - Palpitations and arrhythmias (AV block, SVT, VT) are common also. - If toxicity is severe, given digoxin-specific antibodies (Fab fragments). - *Afterload reduction (Vasodilators): Important in remodeling or manipulating ventricular load - ACE Inhibitors - Sodium nitroprusside - Cyanide toxicity is a concern if given for >48 hours - If pt is in the ICU with an unexplained metabolic acidosis, consider prolonged use of sodium nitroprusside as a cause. - Tx options for suspected cyanide toxicity, after discontinuing the drug, are sodium thiosulfate or hydroxocobalamin (vitamin B12). - Beta blockers

Answer 20

VSD - Most common congenital heart lesion recognized in term newborns (25-30% of cases) in the first few years of life. (Bicuspid aortic valves are the most common congenital heart lesion but often are not recognized until teen or young adult ages.) - At birth, a majority of VSDs occur in the muscular septum, but these usually close spontaneously at <1 yo. - After 1yo, the majority of detected VSDs occur in the perimembranous septum (bw aortic and tricuspid valve) - Pt: - Most symptoms begin in term infants 4-8 weeks of age and consist of tachypnea, tachycardia, and feeding difficulties (classic heart failure symptoms in infants). - Murmur: Holosystolic murmur - A small VSD, which does not allow any equalization of pressure between the LV and RV, has a high intensity murmur whereas a large VSD, which allows complete equalization of pressure between the LV and RV, can cause a soft murmur across the VSD - Tx: Close persistent shunts that have >2x the normal pulmonary blood flow. - Asymptomatic infants: Reevaluate periodically - Symptomatic infants: Has signs of HF - Go straight to cardiology consultation (if not available, order an echo) - Surgery for larger defects or defects in the inlet or outlet septum, particularly with elevated R heart pressures by 6-12mo - For muscular or perimembranous defects, medical therapy is given a chance bc these are more likely to decrease in size or even close spontaneously over time.

Answer 21

Patent Ductus Arteriosus (PDA) - Incidence is inversely related to gestational age. Premature infants (weighing <1750g) have clinically apparent PDA 40-70% of the time. - Normal: - The PDA functionally closes within 10-15 hours after birth, but complete anatomic closure may not occur for 3 weeks. - Murmur: Continuous “machinery-like” systolic murmur - Pt: - If PDA is small, child is otherwise asymptomatic - If it is large, it causes a L-to-R shunt like a VSD, causing pulmonary overcirculation - Bounding pulses and a wide pulse pressure on exam - Tx: - Bounding pulses and a wide pulse pressure on exam - Supportive care, including correcting anemia along with modest fluid restriction. PEEP is useful in managing PDA - Pharmacological closure using cyclooxygenase inhibitors (indomethacin, ibuprofen, tylenol). Treat premature infants with indomethacin (prostaglandin inhibitor). - Side effects: Oliguria, dilutional hyponatremia, intestinal perforation - Should not be used if infant has any of the following - Necrotizing enterocolitis - Serum Cr >1.6 - Hourly UOP <1 - Bleeding diathesis - Platelet count <50,000/uL

Answer 22

PFO - Pt: No physical findings or symptoms result. - NO MURMUR - Usually, the PFO is small and of no clinical significance in childhood.

Answer 23

Ostium Secundum Defect - Pt: - It is rare for an infant to present with symptoms from an ASD until 1yo. - Cardiac failure is very unusual in infancy. - Murmur: - S1 is normal and S2 is widely split (fixed split S2) without respiratory variation (“fixed splitting”). - Systolic ejection murmur that is crescendo decrescendo and heard best at the L upper sternal border. - The murmur is from increased flow across the RV outflow tract (RVOT) and pulmonic valve. - EKG shows RAD (R axis deviation), RVH, and a typical rsR or rSR’ pattern in the R precordium (V1) - Tx: - Usually, perform closures within the first 5 years of age to prevent complications.

Answer 24

Ostium Primum Defect - Pt: - In addition to typical exam findings, may hear mitral and tricuspid regurgitation murmurs if the clefts occur in these valves. - EKG shows LAD (L axis deviation) and RVH, demonstrated by an rsR’ pattern in the R precordium. - The LAD distinguishes the ostium primum defect from the ostium secundum defect. - Tx: - Perform early surgical correction in childhood.

Answer 25

Complete AV Canal Defect (AV Septal defect, Endocardial Cushion Defect) - The overall result is a L-to-R shunt and valve regurgitation, leading to a cardiac volume overload and HF. - Most common heart defect in Down syndrome (trisomy 21) - Murmur - Characteristic murmur of VSD (though usually the VSD is large and nonrestrictive and therefore does not cause a murmur), as well as a middiastolic rumble - Pt: - Infants most often present with heart failure by 2 months of age. - EKG usually shows severe LAD (northwest axis) and prominent voltages with biventricular hypertrophy - Tx: - Medical management of HF can be helpful, but early surgery is necessary within the first 6-12 mo to prevent pulmonary vascular disease (Eisenmenger syndrome).

Answer 26

Pulmonary Hypertension - Path: 2 causes: - 1) An increase in R-sided pressure, due to a large septal defect and very high pulmonary flow - 2) An increase in PVR - Eisenmenger syndrome - Pt: - Pulmonary HTN can present as a narrowly split or single 2nd heart sound with a loud pulmonic component. - CXR classically shows a large proximal pulmonary artery. - Tx: - Correct the underlying cause if present

Answer 27

Eisenmenger Syndrome - L-to-R shunts can have serious consequences if not managed appropriately. The persistence of high flow and pressures in the pulmonary arteries from long-term L-to-R shunting can lead to progressive and permanent, or fixed, elevation of pulmonary resistance, irreversible pulmonary HTN, and subsequent R-to-L shunting and cyanosis (as above) - Eisenmenger syndrome. - Usually symptoms do not develop until the 2nd or 3rd decade of life. - Physical exam: RV heave, palpable single S2, diastolic murmur of pulmonic insufficiency, and a pulmonary click. - Can be lethal.

Answer 28

Coarctation of the Aorta - Infantile coarctation is usually preductal or at the level of the ductus arteriosus, causing systemic blood flow after the aortic narrowing to be dependent on a patent ductus arteriosus (PDA). - Associations: - Turner syndrome is frequently associated with CoA, so all infants with Turner’s should have a cardiology evaluation. - Pt: - Prior to ductal closure, infants often have a lower O2 sat in LEs because PDA is supplying blood flow to the lower body from their R heart. - Saturation differential >10% bw the RUE and LEs is considered clinically significant and should prompt an evaluation for coarctation. - Once the PDA closes, pts develop worsening congestive heart failure and decreased cardiac output / cardiogenic shock. - CXR findings are classic, most often seen in older children, and consist of cardiomegaly, the “3” or reverse “E” sign (which is the notching of the aortic isthmus in the L superior mediastinum), and rib notching due to erosion of the ribs from the large collaterals. - Dx: - Best next step is LE systolic blood pressure measurement to reveal suspected diagnosis: A decreased systolic blood pressure in the leg relative to the RUE is concerning for coarctation of the aorta. - Any child or adolescent being evaluated for HTN should have 4 extremity BPs measured to rule out coarctation as a cause - Confirm with echocardiography, CT, or MRI - Tx: - Timing of therapy depends on severity of lesion, but if coarctation is not corrected before 8yo, irreversible systemic HTN can develop. - Prostaglandin infusion - Surgical or transcatheter repair

Answer 29

Aortic Valve Stenosis - Associations: - Bicuspid aortic valves are the most common form of congenital heart disease, occurring in as many as 1-2% of the population. - Pt: Depends on the degree of obstruction - In severe AS, infants prior to ductal closure have a harsh systolic crescendo-decrescendo ejection murmur at the R upper sternal border. - Once the PDA closes, infants present in shock bc they are not able to get adequate blood flow to their bodies. - Less severe or progressive, older children have typical AS murmur, a systolic crescendo-decrescendo ejection murmur at the RUSB with radiation to the neck. - EKG typically shows LVH and can show LV strain (ST depression in the L lateral leads). - Tx: - Severe in neonates: - Initial tx is PGE1, to attempt to open the PDA and restore adequate cardiac output, followed by inotropic support for the LV. - Intervention is indicated if the Doppler gradient measured by Echo is >70mmHg (or catheter-measured gradient >60mmHg).

Answer 30

Supravalvular Aortic Stenosis - Narrowing that occurs just above the level of the coronary arteries. - Can be isolated, but is most commonly seen in Williams syndrome (result of defect in elastin) - Murmur: Frequently hear a systolic murmur (without click) at the base and toward the neck. - With supravalvular AS, the jet directed into the innominate (aka brachiocephalic) artery usually results in a BP that is 15mmHg higher in the RUE than in the LUE (aka the Coanda effect).

Answer 31

Pulmonary Stenosis - 2nd most common of the congenital cardiac defects recognized early in life (VSD is the most common) - Associations: - Alagille syndrome (arteriohepatic dysplasia) is associated with supravalvular PS or branch PS - Noonan syndrome is also associated with PS. - Pt: - Majority of children with PS are asymptomatic. - In critical pulmonary stenosis, the RV cannot eject the total systemic venous return; thus, pulmonary blood flow through the pulmonic valve is markedly diminished. - Infants with severe PS present in early infancy with severe cyanosis due to cardiac collapse as the ductus closes. - The need for PGE1 therapy to maintain a PDA and sufficient pulmonary blood flow defines critical pulmonary stenosis. - Murmur: Systolic ejection click (that varies with respiration) along the L sternal border that is followed by a harsh, systolic crescendo-decrescendo murmur. You can hear this murmur best at the upper L sternal border, and it radiates to below the L clavicle and often to the back. - EKG typically shows peaked P waves (lead II) indicating the RA enlargement, as well as RAD and RVH. - CXR shows RV prominence and prominent main pulmonary artery with normal pulmonary blood flow. - Tx: - Mild stenosis - no treatment - Moderate (RV pressure >50% of systemic pressure) - severe (RV pressure > systemic pressure) - develop problems over time and should have pulmonary balloon valvuloplasty or surgical valvotomy. - Neonates with severe pulmonary stenosis should be transferred to a center with neonatal cardiac catheterization capabilities for balloon valvuloplasty.

Answer 32

Peripheral Branch Stenosis / Peripheral pulmonic stenosis - Up to 6-12 months of age, a “physiologic” branch pulmonary artery stenosis occurs and produces an innocent murmur - usually Grade 1-2/6 radiating to both axilla and all lung fields. It resolves with growth.

Answer 33

Mitral Valve Stenosis - Path: Most common cause is rheumatic heart disease 2-3 decades following acute rheumatic fever - The pulmonic component of the 2nd heart sound is usually loud bc of the associated pulmonary HTN. Normally, you hear an apical diastolic murmur but typically not an opening snap in infancy bc the valve is so thick and immobile. - EKG shows broad-notched P waves, indicative of the LA enlargement, but RVH is present (rather than LVH) due to the pulmonary HTN. - Tx - Medical management of severe congenital mitral stenosis with HF is rarely successful. - Mitral stenosis can also be a late sequela of rheumatic fever.

Answer 34

Tricuspid Stenosis | - RA enlargement is common, and this frequently manifests an EKG with a large, peaked P wave.

Answer 35

CYANOTIC CONGENITAL HEART DISEASE (RIGHT TO LEFT SHUNT) - Right-to-left shunting presents in the newborn with cyanosis. - A quick way to help determine whether the cause of the symptoms is due to heart disease or pulmonary issues is the hyperoxia test. - This is done by administering 100% oxygen to the infant and noting the change in PaO2. If the cause is due to cyanotic congenital heart disease, then there is little change in the PaO2. However, if the PaO2 increases significantly, then pulmonary causes are likely. - Diagnostic test is echocardiogram - Complications - Chronically cyanotic patients have polycythemia, which increases the chance of thromboembolic events.

Answer 36

Tetralogy of Fallot - Most common cyanotic heart lesion in children. - Path: - 1) Ventricular septal defect. 2) Overriding aorta. 3) Right ventricular outflow tract obstruction with Pulmonic stenosis (single S2) 4) Right ventricular hypertrophy (R axis deviation on ECG, harsh systolic ejection murmur over LV sternal border) - Physiology - In hypercyanotic spell, the SVR drops in response to fever/crying/other cause of vasodilation. - Greater and greater percentage of blood to peripheral circulation will be desaturated as spell progresses and show as lower systemic saturations on pulse ox. - The pulmonic stenosis murmur during hypercyanotic spell will become softer due to decrease in pulmonary flow. - Degree of cyanosis depends on the degree of RVOT obstruction - If there is severe RVOT obstruction, only a portion of the blood can cross the RVOT and the rest shunts from R to L across the VSD to be ejected out the aortic valve. Because this is deoxygenated blood, this lowers the overall saturation of blood going into the aorta and causes cyanosis. - If the RVOT obstruction is very mild, the shunt is determined by the systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR), which almost always favors a L-to-R shunt; the pts present with symptoms of a large VSD and little or no cyanosis (aka “pink tetralogy”). These pts typically present later in infancy with symptoms of heart failure. - Things that raise the PVR (eg bearing down, screaming, reflux/aspiration) and things that decrease the SVR (eating, vasodilation from meds, heat exposure) cause increased R-to-L shunting and worsened cyanosis. - Squatting increases SVR (similar to bringing knees to chest) and increases oxygen saturation. - Pt: - Older children will become cyanotic with episodes of exertion (crying or feeding). - Increases in PVR plus increases in the muscular, subvalvular PS, can cause a “tet,” aka hypercyanotic spell. If severe, these spells can lead to critical cyanosis, seizures, and death. - Murmur: Systolic ejection murmur best at the L upper sternal border (pulmonic stenosis). - As the murmur is typically from pulmonary stenosis, in these spells, the murmur typically softens due to decreased flow through the pulmonic valve. - EKG shows RAD and RVH. - CXR shows boot shaped heart and decreased pulmonary vasculature. - Tx: - Neonates are often asymptomatic, but PGE1 is helpful in the neonate with severe cyanosis. If an infant requires PGE1, they also require surgical correction or palliation before discharge. - Prompt initiation of prostaglandin infusion to reopen ductus arteriosus, which is urgent and can be life saving. - To treat hypercyanotic tet spell (episode of cyanosis), goal is to increase systemic vascular resistance to increase R ventricular preload and improve flow through the R ventricular outflow obstruction. To increase SVR quickly and decrease R-to-L shunt, infant should be placed in knee-to-chest position. - Calm child (decrease PVR) - 1. Placement in knee-chest position to increase SVR - 2. Administration of oxygen with calming measures to increase saturation (decrease PVR) - 3. Placement of IV to give fluid bolus - Give beta blocker (slows the heart rate and allows increased RV filling, which can decrease RVOT stenosis) - 4. Administration of morphine, either IM or subq (slows the heart rate) - Surgery, usually by 6-12 months but sometimes earlier - Once a child develops tet spells, surgical tx is always indicated. - Pts with repaired tetralogy of fallot require serial monitor for the rest of their lives due to the risk of RV dilation from pulmonary regurgitation and arrhythmias. - Repair is a balance between relieving the obstruction and creating pulmonary regurgitation, which is often unavoidable. Pulmonary regurgitation leads to progressive RV dilation. - Complications are rare, but the most common is post-op ventricular arrhythmias (<1%). Remember the association of ventricular arrhythmias in post-op TOF with residual PS or severe pulmonic insufficiency (PI).

Answer 37

Dextro-Transposition of the great arteries - Most common cardiac cause of severe cyanosis in the newborn during the first few days of life. - Path: - Great arteries are switched from their typical location, resulting in 2 parallel circulations instead of in-series circulations. - Pt: - Infant with transposition without a VSD usually presents in the first few hours after birth. The only initial presenting sign in an otherwise healthy-appearing baby is often severe cyanosis. - Murmur: Single, loud 2nd heart sound - CXR can vary from normal to the classic findings - egg-shaped or oval-shaped heart with a narrow mediastinum (due to the aorta being in front of the main pulmonary artery and small thymus). Usually see classic finding in only ~33% of affected infants. - Tx: - The parallel circulations must somehow connect or the infant dies quickly. Survival in the immediate postnatal period relies on a PFO and PDA to mix blood. - Half of the infants with d-TGA also have a VSD, which can also aid mixing. - Initiation of prostaglandin PGE1 infusion to maintain an open ductus arteriosus can be life saving. - TOC: Neonate will require an atrial switch operation soon after birth once the infant is stabilized. - Without surgical correction, mortality in the 1st year of life is >90%.

Answer 38

Levo-Transposition of the Great Arteries - This results in reversal of the ventricles, with the RV serving as the systemic pump and the LV supplying the pulmonary circulation. - Isolated l-TGA is not associated with a R-to-L shunt with cyanosis. - Up to 90% have an associated heart defect (eg VSD, tricuspid and mitral valve abnormalities, pulmonary outflow obstruction).

Answer 39

Double Outlet RV (including Taussig-Bing Anomaly) - Rare group of disorders in which both the aortic and pulmonary valves are positioned over the RV, and the only outflow from the LV is through a VSD. - Tx: Surgical correction is the only treatment option.

Answer 40

Tricuspid Atresia - The tricuspid opening does not exist, meaning that the only way of getting blood out of the RA is via the PFO. - Usually, there is a VSD. Pulmonary blood flow is across the VSD, through the hypoplastic RV, and into the PA (pulmonary artery). - If there is severe PS or a small VSD, a PDA is necessary to supply adequate flow and oxygenation. - Pt: - Cyanosis appears within hours to days after birth, when the ductus begins to close. Cyanosis is the key presenting sign. - Differs from the 2 other cyanotic diseases (TOF and d-TGA) bc of the presence of LAD and LVH - Small VSD and/or severe PS show up on CXR as diminished pulmonary vasculature and a small heart with a round or “apple-like” shape; large VSD and/or mild PS demonstrate increased pulmonary markings and a large heart. - EKG shows L superior axis deviation (0 to -60 degrees) and LVH with decreased RV forces for an infant. This is helpful since the other 2 common cyanotic diseases, TOF and complete transposition, have RAD and LVH. - Tx: - If there is significant cyanosis, initiate PGE1 and then perform a palliative systemic-pulmonary shunt

Answer 41

Pulmonary atresia with intact ventricular septum - EKG shows inferior QRS axis (0-90 degrees) with LVH, while in tricuspid atresia, you see superior QRS axis with LVH. - Tx: - Give PGE1 - Also consider cardiac catheterization to evaluate coronary arteries. At the time of catheterization, you can attempt pulmonary valvuloplasty

Answer 42

What are the congenital heart defects with L axis deviation? Ostium primum ASD, complete AV canal, and tricuspid atresia.

Answer 43

Truncus Arteriosus - A single S2 is heard on auscultation along with an ejection click. - EKG shows RVH or combined ventricular hypertrophy - Tx: - Consists of medical management of HF, but surgery is necessary - Procedure is usually performed in the first few weeks or months of life bc, without surgery, most infants die between 3-12 months of age. - Rastelli operation: Surgeon closes the VSD

Answer 44

Total Anomalous Pulmonary Venous Return (TAPVR) - None of the pulmonary veins drain into the LA. Instead, the pulmonary veins typically drain to a confluence, which then drains via the systemic venous system to the RA - Pt: - Majority of infants present early on with tachypnea and FTT. - This is the one cyanotic congenital heart disease that is not improved with PGE1; if PGE1 is started, severe cyanosis typically develops. - CXR shows a classic “snowman” or “figure-8” silhouette in infants with unobstructive pulmonary venous return to the innominate vein. - Heart in CXR is normal in size, and the lungs show a diffuse hazy pattern resembling “ground glass,” as seen with respiratory distress syndrome. - Tx: In most cases, TAPVR is a surgical emergency, and treatment should focus on initial stabilization and then immediate transfer to a center that performed pediatric heart surgery.

Answer 45

Hypoplastic Left Heart Syndrome - Disorders in which the L side of the heart is underdeveloped. R side of the heart is dilated and hypertrophied and supports both the systemic and pulmonary circulations through a PDA. - Pt: - Most infants are normal at birth (due to PDA) but become acutely ill with signs of poor perfusion, including lactic acidosis, acute HF, and/or cardiogenic shock, when the PDA closes. - Typically, there is no murmur, but a loud, single 2nd heart sound is present - EKG shows RA and RV hypertrophy - Tx: Use PGE1 to maintain the PDA

Answer 46

Aortic Regurgitation - Causes: - Bicuspid aortic valve - Marfan syndrome - Rheumatic fever - Infective endocarditis - Murmur: High-pitched, early diastolic murmur that begins after the aortic component of the 2nd heart sound. - Associations: - Look for a wide pulse pressure - Tx: - With moderate or severe AR, use afterload reduction (ACE inhibitors, hydralazine, and calcium channel blockers) - Do surgery if pt is symptomatic

Answer 47

Mitral Regurgitation - Causes - Most common cause is rheumatic fever worldwide - In the US, most common cause is mitral valve prolapse - Murmur: Apical, high-pitched, blowing holo-systolic murmur. Heard best at apex. Can radiate to the L axilla and the back. - Tx: - Many require no therapy, but in those who are symptomatic, you can use afterload reduction to postpone surgery

Answer 48

Mitral Valve Prolapse - Associations: More likely in Marfan’s (pts have elongated chordae tendineae), Ehler-Danlos, or one of the mucopolysaccharidoses - Murmur: More often, pts with a mid-late systolic murmur at the apex - almost always preceded by >1 click. Classic finding is a mid-systolic click - Extent of prolapse depends mostly on an inverse relationship with LV volume - If volume increases (as when the pt lies down), then the prolapse decreases. - Decreasing the LV volume will accentuate the click and move it closer to S1 - If pt sits or stands (decrease LV volume), the murmur gets longer and the clicks move earlier in the systole; and when the pt squats or lies down, the murmur becomes less noticeable, shorter, and later in systole. - (Note: If they describe an increased early systolic ejection murmur with standing that disappears with squatting, think HCM!)

Answer 49

Mitral valve prolapse - Mid-late systolic murmur louder with standing Hypertrophic cardiomyopathy - Early systolic murmur louder with standing

Answer 50

Pulmonary Regurgitation - Cause: Most common cause is surgery for either pulmonary stenosis or TOF. Congenital pulmonary regurgitation is rare. - Murmur: Early, low-pitched decrescendo diastolic murmur that starts with the pulmonary component of the 2nd heart sound.

Answer 51

Tricuspid Regurgitation - Murmur is pansystolic murmur that is loudest along the lower L sternal border with radiation to the R. Sometimes also hear a low-pitched middiastolic murmur in the tricuspid area

Answer 52

Ebstein Anomaly - Look for the use of maternal lithium and the development of Ebstein’s - Pt: Most pts with Ebstein anomaly are cyanotic soon after birth due to an inability to eject all the RV blood out of the pulmonary valve with R-to-L shunt across the PFO or ASD. - Murmur: Can present as an S3, S4, or triple gallop, but the most common sounds are widely split S1 and S2 sounds with a tricuspid regurgitation murmur (holosystolic murmur along the L lower sternal border) - Look for a huge RA on EKG with wall-to-wall heart shadow on CXR

Answer 53

Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA) - L coronary comes off the pulmonary artery, while the R continues to come off normally from the anterior aortic sinus - Blood flows from the R coronary through collateral vessels into the L coronary, then back into the pulmonary artery. This circulation makes a small, L-to-R shunt, and the blood that should be going to the heart is diverted to the lungs. This results in ischemia of the anterolateral wall of the LV. - Pt: - At 2 weeks - 6 months of age with heart failure from MI or ischemia. - With exercise, both the aorta and pulmonary artery dilate, which can “squish” the misplaced coronary artery and cut off its circulation, resulting in syncope and sudden death - EKG shows an anterolateral infarct pattern with abnormal Q waves in I, aVL, and the L anterior chest leads; additionally, ST and T wave changes often occur. - An infant with CHF and EKG with deep Q waves in the inferior leads (II, III, AVF) should be evaluated for an anomalous left coronary artery from the pulmonary artery (ALCAPA). - Tx: Surgery. Reconnecting the aberrant coronary artery to the aorta.

Answer 54

Other Coronary Artery Anomalies - R coronary artery can arise from the L coronary cusp or the L coronary artery can arise from the L coronary cusp. In either condition, the affected artery can pass between the aorta and the pulmonary artery. - Consider anomalous L coronary artery from the opposite cusp as a possibility in an athlete who reports chest pain with exercise or a sports event in which a young person “passes out” and dies. - (HCM is most common, but coronary artery anomalies are the 2nd most frequent cause of sudden death among young athlete.)

Answer 55

Aberrant R subclavian artery | - Most common aortic arch abnormality, but it rarely causes symptoms

Answer 56

Right aortic arch | - Very common in TOF or truncus arteriosus

Answer 57

Double aortic arch - Persistence of both R and L 4th embryonic arches - Most common symptomatic anomaly.

Answer 58

Note: Remember to look for complete or partial 22q11.2 deletion (DiGeorge) syndrome in infants with aortic arch abnormalities!

Answer 59

Normally (in the absence of intracardiac shunts), the mixed venous saturation is 75% (70-80%) in the superior vena cava, and this remains constant through the RA → RV → PA.

Answer 60

Each large box = 0.2 sec = 5mm | Small box = 0.04 sec = 1mm

Answer 61

PR | - Normal duration is 3-5 small square (120-200ms)

Answer 62

QT - Varies with heart rate (which is why need to correct) - Formula for corrected QT interval is: - QTc = QT / Square root of RR in sec - Rule of thumb is QT interval is normally ~40% of RR interval - Abnormal prolonged QTc - Men >0.45 sec - Women >0.46 sec - Look at chart for pediatrics - QTc > 0.46 sec in children and adolescents (<15yo)

Answer 63

P Wave - Normal P wave is <2mm in height and <120ms (3 small squares) in duration, and the normal P wave axis is 0-90 degrees. - Normal PR interval is 120-200ms. - Because atrial depolarization traverses from the patient’s right to left, the normal P wave is positive in leads I, II, and aVF and is positive or biphasic in V1. - RA enlargement causes peaked P waves in II and V1. - The most sensitive EKG finding for LA enlargement is a broad negative P wave in V1, with a duration of >40ms (>1 small square wide and 1 small square deep).

Answer 64

QRS Complex | - Normal duration of QRS is <100ms (2.5 small squares)

Answer 65

Pathologic Q wave - Deflection amplitude of >25% of subsequent R wave, or being >0.04s in width and >2mm in amplitude. Requires presence of pattern in more than one corresponding lead.

Answer 66

ST Segment - ST-segment elevation - Seen in most leads in pericarditis - Early repolarization - ST segment depression occurs with - Subendocardial ischemia (esp if downsloping or flat), such as with classic angina in adults - LVH with strain (ST depression with flipped T waves in L precordial leads) - RVH, which can cause RAD and ST-segment depression in V1 - Digitalis effect - Hypokalemia

Answer 67

T Wave - The T wave is usually positive in V1 at birth. It remains positive for up to 7 days, then inverts in V1. The T wave typically remains inverted in V1 until 9-10 years of age, and then it can be either inverted or upright in V1 during the teen years. If the T wave remains positive after 7 days of age and up to 10 years of age, this can indicate R ventricular hypertrophy. - T waves can be negative in the L precordial leads (V4, V5, V6) at the time of birth and then can rapidly become upright - Peaked T waves can occur with: - Hyperkalemia - Intracerebral hemorrhage

Answer 68

U Wave - Prominent U wave - If the U wave is prominent, there is an increased tendency for torsades de pointes. - Can be seen with hypokalemia, bradycardia, and drugs such as digitalis and amiodarone.

Answer 69

Left Ventricular Hypertrophy - Leftward shift of the QRS axis increases the R wave and decreases the S wave in V5 and V6 - and the posterior shift of the QRS axis results in a decrease in the R wave and an increase in the S wave in V1. - LVH is also diagnosed by voltage criteria. Evaluate LV forces with the S wave in V1 or the R wave in V6. If either are >95%ile, considered LVH. - Is there a negative T wave in lead V6 after 7 days of life? If so, think LVH.

Answer 70

Right Ventricular Hypertrophy - The normal term infant has RV wall that is thicker than the LV wall and has physiologic “normal” RVH. - Dx: R wave >95th% in V1 or an S wave >95th%ile in V6 - Also look for a “pure” R wave, R >25mm voltage, or a qR pattern in the R chest leads - this suggests pathologic RVH in the newborn. - For older adolescents and adults, EKG criteria for RVH are: - R axis deviation - rsR’ in V1 and V2 (R’ is larger than r) - ST-segment depression and a flipped T wave (due to repolarization changes) in: - V1 - Sometimes V2 - These generally indicated RV stress/HTN

Answer 71

Katz-Wachtel phenomenon - Tall diphasic RS complexes at least 50mm in height in lead V2, V3, or V4 (mid precordial leads). Sign has been described in VSD with biventricular hypertrophy in children.

Answer 72

Sinus Arrhythmia - Normal changes in the sinus rate that occurs with breathing. With inspiration, HR/sinus rate increases (due to vagal withdrawal). With expiration, the sinus rate decreases (due to vagal tone enhancement).

Answer 73

Premature Ventricular Contractions (PVCs)- unifocal or multifocal - QRS (usually wider QRS) not preceded by P wave. - Remember: Cardiac tumors can cause multiple types of PVCs, and cardiac rhabdomyomas are seen in tuberous sclerosis. - Persistent PVCs or those that become more frequent with exercise are more worrisome. - If the history is concerning, then an echocardiogram should be obtained to rule out structural heart disease. - Tx: - Do not need to treat asymptomatic, simple PVCs (even if pt has thousands each day) - Also, do not treat complex PVCs if the pt is asymptomatic and has no underlying heart disease - A beta blocker is usually the 1st line treatment for significant and/or PVC-related symptoms.

Answer 74

Premature Atrial Contractions (PACs) - Early beats originating from atrium. Common in childhood, particularly in newborn and young infant - Vastly considered benign.

Answer 75

Paroxysmal Supraventricular Tachycardia (PSVT): Narrow QRS, absent Ps, same RR interval, fast HR - Path: - AV reentry, due to an accessory pathway connecting the atria and ventricle, is the leading cause of SVT in newborns, infants, and young children - AV node reentry is the leading cause in adolescents and adults. - Pt: - Often have an ABRUPT onset and ABRUPT termination of tachycardia bc >90% of pediatric SVT has a reentrant mechanism - Because SVT can go unrecognized in infants for a long period of time, these patients can present with heart failure. - Rhythm is regular, but rate is very high (~280bpm in neonate or infant and >150bpm in the older child). Usually, the P wave is not visible (buried in the QRS); however, if seen, it is typically retrograde (upside down following the QRS). - Tx: Depends on whether patient is hemodynamically appropriate - If hemodynamically stable: - Vagal maneuvers (cough, ice packs to face for 10-20 sec, blow syringe, NO carotid sinus massage). Valsalva may terminate the SVT while IV access if being obtained. - If vagal maneuvers unsuccessful, IV Adenosine 0.1 mg/kg is TOC followed by adenosine 0.2 mg/kg if rhythm persists. - Or give IV verapamil - Avoid verapamil in infants (<1 yo)! - If patient unstable (unconscious, no pulse, hypotensive, etc), Synchronized DC cardioversion - Long-term control can be achieved with - Oral beta-blockers, digoxin (avoid in WPW), or calcium channel blockers (use caution in infants).

Answer 76

Junctional ectopic tachycardia (JET) is a rare type of supraventricular tachycardia. It is an automatic (nonreentry) arrhythmia, where the junctional rate exceeds the rate of the sinus node and AV dissociation occurs; therefore, P waves do not occur before each QRS complex. - Most commonly, JET is seen postoperatively after cardiac surgery. IV amiodarone is effective tx for postop JET. - Congenital JET can also be seen, and usually occurs within the first 6 months of life as a persistent, sustained form. Many cases of congenital JET present initially with signs of heart failure, including failure to thrive, poor feeding, and sweating while feeding. Often diagnosed before 6 weeks when tachycardia is noted on exam and an EKG shows a narrow complex tachycardia with AV dissociation.

Answer 77

Ectopic atrial tachycardia (EAT) - Narrow complex arrhythmia with unusual P wave morphology or axis. - Underlying causes, such as electrolyte, acid base, or thyroid abnormalities or inappropriate central line position, should be sought out and treated in pts with new-onset arrhythmias.

Answer 78

Atrial Fibrillation - Irregular ventricular rate of 130-200 bpm (about same as the ventricular rate of A-flutter with 2:1 AV block) - Caused by multiple atrial reentry circuits. With new-onset A-fib, or in A-fib unresponsive to usual treatment, consider hyperthyroidism, hypomagnesemia, alcoholism/cocaine abuse, and excessive caffeine and nicotine as possible causes. - Tx: - Can ordinarily treat rapid ventricular response of chronic A-fib with digoxin, but also consider diltiazem, verapamil or beta-blockers if the heart is healthy (ie can tolerate the negative ino-/chronotropic effects) - Anticoagulate for 3 weeks before cardioversion if the pt is stable, and continue to anticoagulate for at least 6 months after successful cardioversion.

Answer 79

Atrial Flutter - Irregular atrial rate of 230-420 bpm (up to 500 bpm in newborns); normally with a 2:1 or 3:1 AV block, resulting in a ventricular rate (or palpable pulse) in the range of 120-200 bpm. - Path: - Typically due to reentry within R atrium and around the tricuspid annulus. - Isolated presentation in an otherwise healthy fetus or newborn is occasionally seen. Long-term controller medications are rarely needed bc the arrhythmia almost never recurs - In older pts, it is usually an indication of underlying cardiac disease - EKG: Sawtooth pattern - Tx: - Use antiarrhythmic drugs for nonemergent cardioversion. Typically, can control rate by slowing AV node conduction with IV diltiazem, digoxin, or a beta-blocker. Can attempt conversion of the atrial rhythm with agents such as ibutilide (corvent), procainamide, flecainide, sotalol, or amiodarone- depending on the clinical situation. - For acute A-flutter in infants <1yo, do not use verapamil bc it can cause hypotension. - Most effective tx is synchronized electrical cardioversion. - Note: adenosine does not convert A-flutter bc the reentrant pathway does not involve the AV node. However, it can block AV conduction, blocking the QRSs on EKG and allowing the flutter waves to be seen if the diagnosis is not clear.

Answer 80

Wolf-Parkinson-White (delta wave with shortened PR interval) - Path: Accessory pathway between atria and ventricles. This can lead to pre-excitation (early partial depolarization of ventricles) - Accessory pathway (Kent bundle) conducts faster than the AV node, and therefore a portion of the electrical current reaches the ventricle sooner (the delta wave on the EKG) and preexcites the ventricle. - Definition - PR interval is <0.12 seconds due to delta wave - Total QRS is >0.12 seconds because of the fusion bw the normal QRS and the preexcited depolarization, which bypasses the AV node - Tx: - Better to treat acute a-fib or a-flutter in WPW with IV procainamide. - NEVER treat acute atrial fibrillation or atrial flutter in the setting of WPW with digoxin. - Radiofrequency ablation is now considered TOC for older children and adolescents with SVT and WPW, and occasionally for A-fib - Most electrical cardioversion of SVTs can be terminated with low energy; the exception is A-fib, which usually requires higher energy (>100W in older child)

Answer 81

Ventricular Tachycardia - Definition: >3 sequential PVCs occurring at a regular rate of >120bpm. Most occur at 150-200bpm - Tx: - If the pt is stable, you can use lidocaine, procainamide, or amiodarone. (Amiodarone is preferred in ACLS and PALS protocols.) - If VT lasts >30 sec or is unstable, it is usually due to organic heart disease. These pts have a high risk of sudden death; therefore, bc of this danger, immediately use synchronized electrocardioversion in any pt with a WIDE QRS tachycardia AND hemodynamic deterioration (treat like V-fib). - Do not ever use verapamil with any wide complex tachycardias in the emergency setting - 30% of those with VT rapidly deteriorate!

Answer 82

Ventricular Fibrillation - Tx: - Survival requires immediate cardiopulmonary resuscitation and defibrillation to establish an effective ventricular beat. - Amiodarone or lidocaine can be given and defibrillation readministered if needed.

Answer 83

Torsades de Pointes - Irregular QRS complexes that appear to twist around the baseline of the EKG, which means “twisting of the points.” It is often associated with a prolonged QT interval and a prominent U wave. - Path: - Do not forget about the prolonged QT syndrome as an etiology. - Tx: Mg - Magnesium sulfate - Shock for sustained torsades de pointes bc pt is unstable. - Do NOT give quinidine or procainamide - any class Ia antiarrhythmic worsens torsades de pointes.

Answer 84

AVOID verapamil with - Infants <1yo - A-fib occurring in WPW - A-flutter - Wide complex tachycardias - Beta-blockers - relative contraindication bc they are both negative chronotropes and negative inotropes. OK to use verapamil (but never in infants!) - To control the ventricular response to A-fib in an otherwise healthy heart - For PSVT (2nd choice after adenosine)

Answer 85

V fib / pulseless V Tach - Defibrillate (2 J/kg); Amiodarone or lidocaine V Tach with pulse - synchronized cardio version (1 J/kg) to prevent fib SVT - vagal maneuvers; Adenosine; synchronized cardioversion Afib - CCB/BB Torsades - Mg Brady Block - Atropine Synchronized shock for SVT, a flutter, VT with pulse

Answer 86

In neonates - Causes of bradycardia: Birth asphyxia, increased ICP, hypothyroidism, congenital heart disease, and heart block. - Think maternal SLE in an infant with complete heart block!

Answer 87

1st degree AV block | - Prolongs PR interval >0.20 sec (1 big square)

Answer 88

2nd degree Mobitz Type I (aka Wenckebach) | - Progressive PR prolongation over time until there is a QRS drop (ventricular beat).

Answer 89

2nd degree Mobitz Type II | - Normal PR interval, and periodically a drop in QRS.

Answer 90

3rd degree AV block / Complete heart block - No atrial depolarizations are conducted through the AV node. P wave and QRS have independent regular rhythms at differing rates (AV dissociation). - If the QRS complex has a normal width (<100 ms), there is a junctional ectopic pacemaker. - Can be seen in infants of mothers with SLE. - Tx: - Permanent pacing is indicated for symptomatic 2nd degree Mobitz 2 and most 3rd degree heart blocks.

Answer 91

Prolonged QTc - Causes: - In a child without medications, it is most likely genetic or congenital prolonged QT syndrome - Romano-Ward syndrome = Prolonged QTc only (without sensorineural hearing loss) - AD inheritance - Jervell and Lange-Nielsen = Prolonged QTc and sensorineural hearing loss - AR congenital long QT syndrome caused by molecular defects in K channels - Tricyclic overdose (esp in adolescent) (such as flexeril/cyclobenzaprine) - Hypocalcemia - Hypomagnesemia - Hypokalemia - Class Ia and III antiarrhythmics (Ia = quinidine, procainamide; III = amiodarone, sotalol) - Starvation with electrolyte abnormalities - CNS insult - Nonsedating antihistamines (removed from the US market) - Azithromycin - Liquid protein diet - Medications are the most common cause of acquired long QT disorder. - Prolonged antihistamine use (like zofran) can cause prolonged QTc - Azithromycin will prolong QT interval and should be avoided in patients with long QT syndrome - Complications: - At risk for ventricular arrhythmias (V tach, V fib, torsades de pointes) and sudden death - There is a tendency to develop recurrent syncope and/or sudden death, due to dysmorphic ventricular tachycardia; ie torsades de pointes. - Tx of congenital long QT syndrome (LQTS): - Beta blockade (eg propranolol, nadolol) to decrease HR and reduce chance of a dangerous rhythm

Answer 92

Short QTc - Causes: - Hypocalcemia and digitalis

Answer 93

Sick Sinus syndrome (sinus node dysfunction) - Pt: >1 of the following - Abnormal sinus bradycardia - Sinus pauses - Sinus blocks - Sinus arrest - Dominant escape rhythms - Tachy-brady syndrome - Look for sick sinus syndrome in a child who has had atrial surgery - ASD repair, atrial baffles in surgically repaired transposition of the great arteries (eg Mustard or Senning operations), or the Glenn or Fontan procedure. - Tx: Because prognosis is good, there are only 2 indications for treatment with pacemaker: - 1) Pt is symptomatic (eg syncope) - 2) Pt has tachyarrhythmias requiring therapy, which might precipitate significant bradycardia

Answer 94

Brugada Syndrome - AD disorder characterized by EKG abnormalities in the R precordial leads - Sodium channelopathy resulting in an RV conduction delay - At risk for ventricular arrhythmia - Typical ECG findings of a pseudo-right bundle branch block and persistent ST segment elevation in leads V1 to V2 - Dx: More challenging in that it is not always pattern; sometimes only identified during fever - Tx: Implantable cardioverter-defibrillator

Answer 95

RBBB - More common in children, particularly after open-heart surgery. - RV is depolarized over a longer period, resulting in a RR’ or RSR’ (“rabbit ears”) in V1 and a wide S wave in V6.

Answer 96

Class I AADs: Na Channel blockers - Ia: Quinidine, procainamide, disopyramide - Quinidine: - Prolongs QRS complex and QT interval - occasionally leading to torsades de pointes - Determine toxic levels by changes in the EKG NOT by serum levels - Cinchonism (ringing in ears, dizziness, diarrhea) - Procainamide: - Prolongs QT and QRS - Side effects: Thrombocytopenia, torsades de pointes - Ib: Lidocaine, tocainide, mexiletine, phenytoin - Lidocaine: Seizures or CNS depression - Ic: Flecainide and propafenone

Answer 97

Class II AADs - Decreases sympathetic activity - beta blockers - Side effects: Bradycardia, can potentially aggravate asthma

Answer 98

Class III AADs: K channel blockers | - Amiodarone, sotalol, bretylium, and the newer agents, dofetilide (PO), and ibutilide (IV)

Answer 99

Class IV AADs: Ca channel blockers - Blocks slow inward Ca2+ current: Calcium channel blockers - Verapamil and diltiazem

Answer 100

Adenosine - Blocks calcium influx - Slows conduction in the SA node and AV node. - Acute SOB following adenosine can be related to bronchoconstriction; treat with bronchodilator (eg terbutaline)

Answer 101

Bicuspid aortic valve - Can be familial or sporadic. - Autosomal dominant. Because of the familial inheritance risk, 1st degree relatives should be screened. - Bicuspid aortic valve is also associated with genetic syndromes such as Turner syndrome - Murmur: - Distinguishes by having a click - Management: - Pts with BAV can develop regurgitation, stenosis, endocarditis, and aortopathy, and therefore need follow-up throughout life. - Should screen relatives for bicuspid aortic valve

Answer 102

Superior vena cava syndrome - Path: External compression of the superior vena cava, resulting in reduced blood return from the upper body and head to the heart. This leads to venous congestion in the face and arms as well as increased intracranial pressure - Usually caused by Anterior mediastinal masses, enlarged mediastinal lymph nodes, and occlusion of SVC itself - Pt: Facial edema and UE swelling, JVD, headache, air hunger, syncope, cough - Dx: CXR- widened mediastinum is suggestive of anterior mediastinal mass. - Management: - The best management option to maintain awakeness, sitting up, and support airway via noninvasive positive pressure. Lying the patient down would worsen the compression of the R atrium, as would sedating the patient. - Treatment for tumor reduction - In severe cases, cardiopulmonary bypass or extracorporeal membrane oxygenation may be needed until SVC compression can be relieved.

Answer 103

Myocarditis - Inflammation of the myocardium that can also affect the electrical system of the heart. This can cause arrhythmias and decreased contractility. - Common causes: Infectious disease and autoimmune disorders - Pt: - Initial presentation can include respiratory symptoms, GI symptoms, palpitations, or chest pain. - Symptoms may be nonspecific and a pt’s condition can decompensate rapidly, leading to cardiogenic shock and sudden death. - Signs of heart failure, including dyspnea, syncope, tachycardia, tachypnea, and hepatomegaly - Infants typically have worse symptoms, including fever, respiratory distress, tachycardia, hypotension, and a heart murmur. Pts with heart failure may have hepatomegaly - Initial evaluation: - CXR may demonstrate pulmonary edema and/or cardiomegaly - EKG may show low voltages, rhythm abnormalities, or conduction delays. - Echocardiogram may show decreased systolic function, pericardial effusion, and/or valvular dysfunction. - Dx: Clinical. - Tx: - Supportive and may include diuretics, inotropes, and respiratory support.

Answer 104

- Hypocalcemia - Hypomagnesemia - Hypokalemia