Chapter 8 - Cardio

Question 1

What is congestive heart failure?

Answer 1

a clinical syndrome defined as inadequate oxygen delivery by the myocardium to meet the metabolic demands of the body

Question 2

What three compensatory mechanisms further compromise the heart in those with congestive heart failure?

Answer 2

• hypoperfusion of end organs triggers tachycardia and an inotropic increase
• hypoperfusion triggers the renin-angiotensin system, which induces salt and water retention, increasing preload
• catecholamines are released which damage the heart through remodeling and through physiologic changes that increase CO

Question 3

What are the clinical features of congestive heart failure?

Answer 3

• tachypnea, cough, wheezing, rales, and pulmonary edema indicative of pulmonary congestion
• hepatomegaly and peripheral edema indicative of systemic venous congestion
• tachycardia, sweating, pale skin, diminished urine output, failure to thrive, poor feeding, and exercise intolerance
• cyanosis and shock late in the disease course

Question 4

Congestive Heart Failure

Answer 4

• inadequate oxygen delivery by the myocardium to meet the metabolic demands of the body
• can be due to increased pulmonary blood flow, obstructive lesions, AV malformations, AV valve regurgitation, viral myocarditis, severe anemia, rapid infusion of IV fluids, etc.
• presenting with pulmonary or systemic venous congestion, tachycardia, diaphoresis, diminished urine output, poor feeding in infants, exercise intolerance, failure to thrive, and potentially cyanosis or shock
• a cycle worsened by efforts to increase cardiac output like tachycardia or inotropic changes, catecholamine-induced cardiac remodeling, and water retention by the renin-angiotensin system
• medically treated with glycosides, diuretics, inotropic medications, and PDE inhibitors like amrinone and milrinone, which improve inotropy and reduce preload

Question 5

What is Still’s murmur?

Answer 5

• an benign cardiac murmur heard between 2-7 years of age in some
• a grade 1-3 systolic murmur heard best at the mid-left sternal border while supine or with exercise

Question 6

What is a pulmonic systolic murmur?

Answer 6

• a benign cardiac murmur that can present at any age during childhood
• a grade 1-2 systolic ejection murmur which peaks early in systole, is heard best at the upper left sternal border, and is loudest while supine

Question 7

What is a venous hum?

Answer 7

• a benign murmur heard most often in school-aged children
• it is a continuous murmur heard best at the neck and below the clavicles and only while sitting or standing
• disappears while supine as positioning changes the compression of the jugular vein

Question 8

What are the three kinds of ASD and how do they differ?

Answer 8

• ostium primum is in the lower portion of the septum and may involve the mitral valve to cause regurgitation; it is associated with Down syndrome
• ostium secundum is in the middle portion of the septum and is the most common type of ASD overall
• sinus venosus is a defect high in the septum near the SVC; the right pulmonary veins usually drain anomalously into the right atrium or SVC instead of the left atrium

Question 9

Atrial Septal Defect

Answer 9

• ostium secundum is the most common type; ostium primum is associated with Down syndrome; sinus venosus is associated with anomalous drainage of the right pulmonary vein into the right atrium or SVC
• an increase in blood flow within the right heart leads to right ventricular hypertrophy, right axis deviation, and right atrial enlargement
• systolic ejection mumur heard at the mid-left sternal border due to increased flow across the pulmonic valve; mid-diastolic filling rumble at the tricuspid area; fixed S2
• ## symptoms are minimal but paradoxical emboli are the important complication

Question 10

Ventricular Septal Defect

Answer 10

• a left-to-right shunt dependent on the size of the VSD and the degree of pulmonary vascular resistance
• strongly associated with fetal alcohol syndrome
• heard as a holosystolic murmur loudest at the tricuspid area and increased with hand grip; may hear a diastolic rumble over the apex if large due to increased flow across the mitral valve; fixed S2
• large VSDs with pulmonary hypertensionare surgically closed at 3-6 months of age
• small-to-moderate are closed between 2-6 years of age as many will spontaneously resolve

Question 11

Eisenmenger Syndrome

Answer 11

the process by which a left-to-right shunt reverses to a right-to-left shunt and becomes symptomatic

• this shunt tends to increase flow through the pulmonary circulation
• the result is pulmonary hypertension, increasing the pressure in the right heart
• eventually the pressure in the right heart is high enough that the shunt is reversed and becomes right-to-left
• presents with right ventricular hypertrophy and adult onset cyanosis with reactive polycythemia and clubbing

Question 12

Patent Ductus Arteriosus

Answer 12

• a left-to-right shunt that increases pulmonary blood flow, presenting a risk for Eisenmenger syndrome and CHF
• heard as a “machine-like” continuous murmur at the left infraclavicular area; a diastolic filling rumble may be heard at the apex as the increase in pulmonary blood flow increases flow across the mitral valve
• may also find a widened pulse pressure and brisk pulses
• indomethacin can be used to close the PDA medically

Question 13

Why do left-to-right murmurs often present with a diastolic murmur at the apex?

Answer 13

because there is increased flow to the right atrium and then across the mitral valve, which is responsible for this finding

Question 14

Coarctation of the Aorta

Answer 14

• a narrowing of the aortic arch just proximal to the ductus arteriosus, often with a PDA and bicuspid aorta
• heard as a bruit over the left upper back near the scapula
• presents with lower extremity cyanosis at birth, hypertension in the right arm and hypotension in the lower extremities, and radio-femoral delay
• may lead to developmental of intercostal artery collaterals with notching of the ribs
• PGE is given to maintain the ductus arteriosus and inferior blood supply, inotropic meds, and low-dose dopamine to maximize renal perfusion and function before surgery
• recurrence of narrowing after surgery is not uncommon and the treatment of choice is balloon angioplasty for these

Question 15

Aortic Stenosis

Answer 15

• heard as a systolic ejection click followed by a crescendo-decrescendo murmur, increased with squatting due to increase in preload
• neonates are likely to appear normal at birth but develop signs and symptoms CHF within 24 hours once the PDA closes
• in neonates, the defect may be associated with left ventricular hypoplasia
• older children present with exercise intolerance, chest pain, syncope, and sudden death
• likely to find a weak pulse with a delayed peak
• treated with surgery after becoming symptomatic

Question 16

Tetralogy of Fallot

Answer 16

• a tetrad of VSD, overriding aorta, pulmonary stenosis, and right ventricular hypertrophy
• degree of disease is dependent on the severity of right ventricular outflow tract obstruction
• presents with a systolic ejection murmur of pulmonary stenosis over the left upper sternal border, RV hypertrophy on ECG, boot-shaped heart on CXR, and right aortic arch
• maneuvers that increase systemic vascular resistance or reduce pulmonary arteriole resistance reduce the right-to-left shunting; patients may learn to squat in order to reduce cyanosis
• treated with surgical repair

Question 17

What is the difference between central and peripheral cyanosis?

Answer 17

• peripheral is usually caused by vasomotor instability or vasoconstriction and is therefore relatively localized
• central is more generallyed and can be cardiac (5Ts) or noncardiac in origin from pulmonary disease, sepsis, hypoglycemia, polycythemia, or neuromuscular disorders that impair chest wall movement

Question 18

What are the 5 T’s of cardiac cyanosis?

Answer 18

• Tetralogy of Fallot
• Transposition of the Great Vessels
• Truncus Arteriosus
• Tricuspid Atresia
• Total Anomalous Pulmonary Venous Connection

Question 19

Transposition of the Great Arteries

Answer 19

• results in circulations in parallel rather than series
• associated with maternal diabetes
• presents as early cyanosis in an infant who appears otherwise healthy with a quiet precordium and no murmur
• a single S2 is common as the pulmonic valve then sits posteriorly and is difficult to hear in this position
• managed with PGE to improve oxygen saturation until surgery can be performed

Question 20

Tricuspid Atresia

Answer 20

• a failure of the tricuspid valve orifice to develop
• an ASD or PFO is always present, but whether or not there is also a VSD determines the direction of blood flow and the degree of cyanosis
• without a VSD there is right ventricular hypoplasia and pulmonary atresia
• with a VSD there may be acceptable systemic oxygenation
• presents with a VSD murmur if one is present, right atrial enlargement on ECG, left axis deviation, left ventricular hypertrophy, and early cyanosis
• surgery establishes vessels so systemic venous return is directed to the pulmonary artery

Question 21

What is the only cause of cyanosis in the newborn period that results in left axis deviation and left ventricular hypertrophy?

Answer 21

tricuspid atresia

Question 22

Truncus Arteriosus

Answer 22

• almost always presents with a VSD
• heard as a systolic ejection murmur at the base from increased flow across the truncal valve and a single S2 caused by the presence of only one ventricular valve
• a diastolic murmur may be heard at the apex due to excess flow through the pulmonary vasculature

Question 23

Total Anomalous Pulmonary Venous Connection

Answer 23

• pulmonary veins drain into the systemic venous side rather than the left atrium
• can be supracardiac into the SVC, cardiac into the RA or coronary sinus, or infracardiac into the portal system
• results in desaturated blood in all four chambers, pulmonary arteries, and aorta with early cyanosis
• heard as a pulmonary flow murmur at the mid-left sternal border

Question 24

What is the most common cause of acquired heart disease in children within the US and worldwide?

Answer 24

• US: Kawasaki disease

- Worldwide: acute rheumatic fever

Question 25

What is a subacute endocarditis versus an acute endocarditis? How do the etiologies differ?

Answer 25

• a subacute endocarditis has a gradual onset and involves small vegetations that do not destroy the valve; this is most often due to a Streptococcus viridans infection (low virulence)
• acute has a more rapid onset and involves larger vegetations that destroy the valve; this is most often due to Staphylococcus auerus

Question 26

What are the most common etiologic agents for endocarditis of the following kinds:

• most common overall
• most common cause of subacute endocarditis
• most common in IV drug users
• most common in those with a prosthetic valve
• most common in those with underlying colorectal carcinoma
• most common in those with negative blood cultures

Answer 26

• overall: Strep viridans
• subacute: Strep viridans
• IV drug users: Staph aureus
• prosthetic valve: Staph epidermidis
• colorectal carcinoma: Strep bovis
• negative blood cultures: Coxiella burnetii, Bartonella spp., and HACEK organism (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)

Question 27

Endocarditis

Answer 27

• eighty percent are associated with pre-existing structural abnormalities of the heart and fifty percent with recent cardiac surgery
• most often caused by Strep viridans and Staphylococcal species in children
• presents with fever, new or changing murmur, splenomegaly, hematuria resulting from embolism or endocarditis-associated glomerulonephritis, splinter hemorrhages, retinal hemorrhages, osler’s nodes on the palms soles or pads of the toes or fingers, janeway lesions, and roth’s spots
• diagnosed with blood culture, elevated ESR, and transthoracic or transesophageal echocardiography
• treated with 4-6 weeks of IV antimicrobial therapy
• prophylaxis is given before invasive procedures to those with structural heart disease, post-op cardiac surgery patients for up to 6 months, and post-op cardiac surgery patients indefinitely if they have hemodynamic residua of their initial lesion

Question 28

Pericarditis

Answer 28

• most often viral, specifically coxsackievirus; can be purulent (bacterial) which is usually caused by S. aureus or Strepneumo and has a higher incidence of constrictive pericarditis; or postpericardiotomy
• in any case, inflammation leads to exudation or trasudation of fluid and impairment of venous return and cardiac filling; cardiac tamponade may occur
• presents with chest pain most intense while supine and relieved by sitting up as well as pulsus paradoxus
• heard as a pericardial friction rub with distant heart sounds
• pericardiocentesis is diagnostic and therapeutic

Question 29

What is pulsus paradoxus?

Answer 29

a more than 10 mmHg reduction in systolic blood pressure on deep inspiration, indicative of pericarditis

Question 30

Myocarditis

Answer 30

• an inflammation characterized by cellular infiltrate and myocardial cell death
• can be caused by viruses (coxsackie), bacteria (C. diphtheriae, S. pyogenes, S. aureus, or M. tuberculosis), Chaga’s disease (T. cruzi), SLE, rheumatic fever, sarcoidosis, or Kawasaki disease
• presents with dyspnea and malaise, resting tachycardia and muffled heart sounds,
• diagnosed with elevated ESR, CKMB, and CRP; etiologic organism can be identified through endomyocardial biopsy
• echo is likely to show an anatomically normal heart with global ventricular dysfunction
• treatment is supportive and mortality is highest in young infants and those with ventricular dysrhythmias

Question 31

What is cardiomyopathy?

Answer 31

an abnormality of cardiac muscle manifested by systolic or diastolic dysfunction

Question 32

Dilated Cardiomyopathy

Answer 32

• a dilation of all four chambers of the heart
• most commonly idiopathic; can be due to alcohol abuse, wet beriberi, coxsackie B viral myocarditis, cocaine, chagas disease, doxorubicin, thyrotoxicosis, carnitine deficiency, or pregnancy
• takotsubo cardiomyopathy is “broken heart” due to ventricular apical ballooning in response to sympathetics
• causes systolic dysfunction with heart failure, arrhythmia, systolic regurgitation and an S3 heart sound
• manage by evaluating viral serologies, serum carnitine level, ECG, and echo
• treat with sodium restriction, ACE inhibitors, B-blockers, diuretics, digoxin, transplant

Question 33

Hypertrophic Cardiomyopathy

Answer 33

• LVH in the absence of any systemic or cardiac disease, typically with asymmetric septal hypertrophy
• most often inherited in an autosomal dominant fashion
• pathophysiology is related to poor left ventricular filling, dynamic left ventricular outflow tract obstruction caused by the anterior mitral leaflet obstructing the sub-aortic region during systole, and a mismatch between myocardial oxygen demand and supply
• ECG shows left ventricular hypertrophy with wide Q waves in the inferior and lateral leads
• treat with beta blockers or CCBs to reduce obstruction and improve diastolic compliance, treat dysrhythmia with anti-arrhythmic, and limit participation in competitive athletics

Question 34

Restrictive Cardiomyopathy

Answer 34

• decreased compliance of the ventricular endomyocardium that restricts filling during diastole
• caused by amyloidosis, sarcoidosis, endocardial fibroelastosis (thick firboelastic tissue in the endocardium of young children), hemochromatosis, Loeffler syndrome (endomyocardial fibrosis with a prominent eosinophilic infiltrate), and post radiation fibrosis
• presents as diastolic heart failure with a low-voltage ECG
• exercise intolerance, weakness, dyspnea, edema, hepatomegaly, ascites
• treat with diuretics, beta-blockers, and CCBs

Question 35

Supraventricular Tachycardia

Answer 35

• an abnormally accelerated heart rhythm that originates proximal to the bifurcation of the bundle of His
• it is the most common dysrhythmia in childhood
• can be either AV re-entrant in which retrograde conduction through an accessory pathway leads to SVT or AV node re-entrant in which the conduction abnormality occurs within the AV node itself
• differs from sinus tachycardia in that rates often exceed 250 bpm, there are absent or abnormal p waves there are no pre-disposing factors, and there is a rapid response to intervention
• presents with palpitations, chest pain, and occasionally altered levels of consciousness
• managed with vagal maneuvers, IV adenosine, cardioversion, and ablation

Question 36

How does sinus tachycardia differ from supraventricular tachycardia?

Answer 36

• sinus tachycardia is almost always less than 230 in newborns and 210 in children but more than 250 in SVT
• there is variation in heart rate in sinus tachycardia but not SVT
• there is a normal P wave in sinus tachycardia but not SVT
• there is usually some inciting factor like fever, infection, anemia, etc. causing sinus tachycardia but not SVT
• sinus tachycardia doesn’t respond quickly to therapy while SVT does

Question 37

Wolff-Parkinson White Syndrome

Answer 37

• the most common type of ventricular pre-excitation syndrome
• results from an abnormal fast accessory conduction pathway from the atria to the ventricles, bypassing the AV node, called the Bundle of Kent
• ECG demonstrates characteristic delta waves, widened QRS complex, and shortened PR interval/segment
• increases risk for a supraventricular tachycardia

Question 38

How is heart block classified?

Answer 38

• first degree: prolonged PR interval
• second degree, Mobitz type I: progressive lengthening of PR interval until a QRS complex is dropped
• second degree, Mobitz type II: consistent PR interval with randomly dropped QRS complexes
• third degree: atria and ventricles beat independently of one another

Question 39

What are the common causes of heart block?

Answer 39

• congenital third-degree is associated with children born to mothers with SLE
• post surgical AV block is common, especially following closure of a VSD
• bacterial endocarditis

Question 40

How does heart block present and how should it be managed?

Answer 40

• presents with fatigue, syncope, and occasionally sudden death
• treat with a pacemaker

Question 41

Congenital Long QT Syndrome

Answer 41

• an inherited disorder of myocardial repolarization
• most often due to ion channel defects
• Romano-Ward is an autosomal dominant condition without extracardial symptoms whereas Jervell and Lange-Nielsen syndrome is autosomal recessive and associated with sensorineural deafness
• presents with syncope, seizure, palpitation, and rarely sudden cardiac arrest secondary to torsades de pointes
• diagnosed based on a QTc greater than 0.44 seconds
• managed with beta-blockers to reduce symptoms but the QT interval usually remains prolonged

Question 42

What is considered a prolonged QTc and how is it calculated?

Answer 42

• QTc = QT/sqrt(previous RR interval)

- prolonged if greater than 0.44 seconds

Question 43

List causes of chest pain in pediatrics.

Answer 43

• cardiac causes: most often pericarditis, hypertrophic cardiomyopathy, aortic dissection secondary to Marfan syndrome
• GI causes like GERD
• respiratory causes like asthma or acute chest syndrome of sickle cell
• MSK: costochondritis or vasoocclusive crisis in sickle cell disease
• psychological casues

Question 44

What sort of chest pain requires additional work up?

Answer 44

that associated with exercise, syncope, shortness of breath, or an abnormal heart rhythm

Question 45

Precordial Catch Syndrome

Answer 45

• the most common cause of chest pain in adolescents
• benign and with unknown etiology
• presents with sudden, sporadic onset of sharp pain, usually along the left sternal border and often exacerbated with deep inspiration
• pain resolves spontaneously after seconds to minutes and can be broken with a forced deep inspiration