Cardiology Flashcards
Hypoperfusion of end organs stimulates the heart to…
Maximize contractility and heart rate in an attempt to increase cardiac output
Hypoperfusion signals the kidneys to…
Retain salt and water through renin-angiotensin system
__________ released by the sympathetic nervous system to increase heart rate and myocardial contractility during hypoperfusion
Catecholalmines
What are some congenital lesions that cause increased pulmonary blood flow?
- Large VSD
- Large PDA
- Transposition of the great arteries
- Truncus arteriosus
- Total anomalous pulmonary venous connection (TAPVC)
What obstructive lesions may cause CHF?
- Severe aortic, pulmonary, and mitral valve stenosis
- Coarctation of the aorta
- Interrupted aortic arch
- Hypoplastic left heart syndrome
What acquired heart diseases may lead to CHF?
- Viral myocarditis (common)
- Endocarditis, pericarditis
- Metabolic disease (hyperthyroidism),
- Medications
- Cardiomyopathies
- Ischemic diseases
- Dysrhythmias
What are clinical features suggesting pulmonary congestion in CHF?
- Tachypnea, cough, wheezing, and rales on examination
- Pulmonary edema on CXR
What clinical features are evidence of impaired myocardial performance in CHF?
- Tachycardia, sweating, pale or ashen skin color
- Diminished urine output
- Enlarged cardiac silhouette on CXR
What clinical features are evidence of systemic venous congestion in CHF?
Hepatomegaly and peripheral edema
What are late manifestations of CHF?
Cyanosis and shock
What types of medical management are used to treat CHF?
- Cardiac glycosides (digoxin)
- Loop diuretics (furosemide)
- Inotropic medications administered IV (dobutamine, dopamine)
What other methods of management are used to treat CHF besides medication?
- Interventional catheterization (balloon valvuloplasty for critical aortic and pulmonary valve stenosis)
- Surgical repair (definitive treatment of CHF secondary to congenital heart disease)
Approximately ___% of children have an innocent heart murmur at some point during childhood
50%
What are the acyanotic congenital heart diseases?
ASD, VSD, PDA, Coarctation of the aorta, Aortic stenosis, Pulmonary stenosis
What are the differences between Ostium primum ASD and Ostium Secundum ASD?
- Ostium Primum: Defect in lower portion of atrial setptum, common in Down Syndrome
- Ostium Secundum: Defect in middle portion of atrial septum, most common type of ASD
What is a sinus venosus ASD?
A defect high in the septum near the junction of right atrium and SVC - the right pulmonary veins usually drain anomalously into the right atrium or SVC instead of the left atrium
How does an ASD lead to increased pulmonary blood flow?
Blood flows from the left atrium to the right (higher resistance to lower resistance) leading to increase in size of the right atrium and right ventricle, and to increased pulmonary blood flow
What are 3 innocent heart murmurs?
- Still’s murmur (ages 2-7)
- Pulmonic systolic murmur (any age)
- Venous Hum (any age, but especially school age)
Describe a still’s murmur
- Grade 1-3, systolic vibratory twanging or buzzing.
- Loudest supine and louder with exercise
- Mid-left sternal border
Describe a pulmonic systolic murmur
- Grade 1-2, peaks early in systole
- Blowing, high pitched
- Upper left sternal border
Describe venous hum
- Continuous murmur heard only sitting or standing - disappears if supine
- Neck and below the clavicles
Patients with a ostium primum defect may develop ______ _______ that results in CHF
mitral regurgitation
Physical examination findings of ASD include:
- Increased right ventricular impulse
- Systolic ejection murmur best heard at mid and upper left sternal borders
- Fixed split second heart sound
What is the management of ASD?
Treatment is closure by open heart surgery to prevent right sided heart failure, pulmonary hypertension, dysrhythmias and paradoxic embolism
What are the classifications of VSD?
- Inlet
- Trabecular (muscular)
- Membranous
- Outlet (supracristal)
How does a VSD lead to pulmonary hypertension?
Blood flows from left to right ventricle owing to lower resistance within pulmonary circulation; with time, the pulmonary vessels hypertrophy in response to increased pulmonary flow leading to increased vascular resistance
What two factors determine the amount of blood flow directed from one side of the heart to the other in a VSD?
Determined by the size of the VSD and the degree of pulmonary vascular resistance (PVR)
As the size of the VSD decreases, the intensity of the murmur _______
Increases (thrill and grade 4 high pitched holosystolic murmur may indicate small VSD)
If excessive blood flows across the VSD (moderate or large VSDs) then a diastolic murmur of _____ _______ may be heard at the apex
mitral turbulence (mitral filling rumble representing excess blood from the lungs no passing through the mitral valve)
What is Eisenmenger syndrome?
If PVR remains elevated, pulmonary hypertension becomes irreversible, even if VSD is surgically closed - PVR exceeds SVR and shunting changes from left-to-right to right-to-left
When is surgical closure indicated in management of a VSD?
- Heart failure refractory to medical management
- Large VSDs with pulmonary hypertension (closed at 3-6 months)
- Small to moderate VSDs are closed between 2-6 years of age
What is the medical management of VSDs?
Medical management of CHF is indicated in a symptomatic child (Cardiac glycosides, Loop diuretics, Inotropic medications administered IV)
What is connected by the ductus arteriosus in the fetus?
Connects the pulmonary artery to the aorta
Incidence of PDA is high in _____ infants
preterm
Physical examination findings of PDA?
- “Machinery-like” continuous murmur at upper left sternal border
- If the left-to-right shunt is large: diastolic rumble of blood flow across mitral valve at the apex
- Widened pulse pressure and brisk pulses
Risk of ______ _______ is significant in children older than several years of age with a PDA
Pulmonary hypertension
_____ is used in premature infants to close a PDA medically
Indomethacin
PDAs may be closed surgically by what methods?
- Coil embolization
- Video-assisted thoracoscopic surgery
- Ligation in a thoracotomy
What is Coarctation of the Aorta?
Narrowing of the aortic arch just below the origin of the left subclavian artery and typically at, or just proximal to the ductus arteriosus
Neonates or infants with severe coarctation may depend on a right-to-left shunt through the ____ for perfusion of the lower thoracic and descending aorta
PDA
What is the key blood pressure finding in coarctation of the aorta?
Blood pressures may be elevated in the upper extremities and low in the lower extremities (before the onset of CHF)
What occurs once an infant with Coarctation of the Aorta develops CHF?
- Pulses in all four extremities are poor
- Any murmur is absent
- Hypotension may develop
What findings are significant for the following in older children or adolescents with coarctation of the aorta?
- Femoral pulse:
- Aortic valve:
- Turbulence:
- Collateral vessels:
- Femoral pulse: is dampened and delayed until after the radial pulse
- Aortic valve: Bicuspid aortic valve or aortic stenosis is present in 50% of patients
- Turbulence: bruit through the coarctation may be audible at the left upper back
- Collateral vessels: Intercostal arteries may develop into collateral vessels which allow the ascending aortic circulation to circumvent the coarctation
Initial management of coarctation of the aorta (2)?
- Intravenous prostaglandin E (PGE) to open the ductus arteriosus
- Inotropic medications are given to overcome myocardial depression
What corrective repairs are used to treat coarctation of the aorta (2)?
- Surgery - excision of the narrowed segment followed by end-to-end anastomosis
- Balloon angioplast is the therapy of choice for recurrent coarctation
What is pathologic aortic stenosis?
Commissural fusion of the three normal leaflets leading to a bicuspid or unicuspid valve
How does aortic stenosis lead to myocardial ischemia?
- Aortic stenosis results in reduced left ventricular output
- Imbalance between myocardial oxygen demand (which is higher than usual due to increased ventricular work as a result of outflow obstruction) and supply
Severe aortic stenosis may be associated with ______ of the left ventricle
hypoplasia (as a result of imparied fetal left ventricular development)
Neonates with severe stenosis appear normal at birth but develop signs and symptoms of CHF at ____ -____ hours of age
12-24 hours of age
Older children who develop severe stenosis show what symptoms?
- Exercise intolerance
- Chest pain
- Syncope
- Sudden death
What are indications for intervention of aortic stenosis?
- CHF
- Chest pain or syncope
- Documentation of high resting pressure gradient across the aortic valve (>50-70 mm Hg)
Management of aortic stenosis?
- Balloon valvuloplast (inital management)
- Surgery for aortic stenosis with insufficiency and 5-10 years after palliative valvuloplasy
What is the Ross procedure?
The aortic valve is replaced with the patient’s own pulmonary valve as a treatment for aortic stenosis
Pulmonary stenosis results in ______ right ventricular pressure and ______ right ventricular output
Increased; Reduced
What symptoms are present in most children with pulmonic stenosis? What happens in severe cases?
Most children: Asymptomatic
Severe: Cyanosis as a result of right-to-left shunting at the atrial level through a patent foramen ovale
What is the management of pulmonary stenosis? When is management indicated?
Treatment is balloon valvuloplasty for symptomatic infants with critical pulmonary stenosis and for older children with significant gradiants across the pulmonary valve (>35-40 mm Hg)
What is the difference between central and peripheral cyanosis?
- Peripheral cyanosis is usually caused by vaosomotor instability or vasoconstriction as a result of cold temp.
- Central cyanosis, especially apparent in the tongue and mucous membranes may be attributable to both cardiac and noncardiac causes
What are some non-cardiac causes of central cyanosis?
Pulmonary disease, sepsis, hypoglycemia, polycythemia, and neuromuscular diseases that impair chest wall function
What are the most comon cardiac causes of central cyanosis?
- 5 Ts
- Tetralogy of fallot
- Transposition of the great arteries
- Tricuspid atresia
- Truncus arteriosus
- Total anomalous pulmonary venous connection
What are the methods of evaluating Cynaosis?
- Physical examination
- Pulse oximetry
- Complete blood count
- ABG, ECG, CXR
- 100% oxygen challenge test
- Echo
What are the four components of Tetralogy of Fallot?
- VSD
- Overriding aorta
- Pulmonary stenosis
- Right ventricular hypertrophy
Which cyanotic congenital heart diseases cause increased pulmonary flow (Pulm Vasc. Markings)? Decreased?
Increased: Transposition of the great arteries, TAPVC, Truncus arteriosus
Decreased: Tetralogy of Fallot, Tricuspid atresia
Which cyanotic congenital heart disease presents with no murmur, a single S2 sound, and a small heart with narrow mediastinum (“egg-on-a-string” appearance)?
Transposition of the great arteries
Which cyanotic congenital heart disease presents with a single S2 systolic ejection murmur along the left sternal border as well as a diastolic murmur at the apex?
Truncus arteriosus
Describe the murmur heard in TAPVC
Pulmonary ejection murmur along left sternal border
What type of murmur is associated with tetralogy of fallot?
Systolic ejection murmur of pulmonary steonsis
What actions increase right-to-left shunting in Tetralogy of Fallot? Which actions reduce cardiac shunting?
- Increase
- Actions that decrease SVR (exercise, vasodilation)
- Actions that increase resistance through RVOT (crying, tachycardia)
- Reduce
- Actions that increase SVR or reduce resistance through the RVOT (volume infusion, systemic hypertension, valsalva, bradycardia)
What is a Tet spell (Tetralogy of Fallot)? How does a child compensate?
Sudden cyanosis and decreased mumur intensity triggered by any maneuver that decreases arterial oxygen saturation
A child compensates by squatting (increases venous return and increases SVR)
What is the definitive management of tetralogy of Fallot and when is it performed?
Complete surgical repair at 4-8 months of age
Transposition of the great arteries arises when the aorta rises from the ______ _______ and the main pulmonary artery from the _____ _______
right ventricle; left ventricle
Adequate saturation in transposition of the great arteries can only occur by…
Shunting blood from one circulation to the other (PFO, ASD, VSD, PDA)
What is the acute management of Tetralogy of Fallot?
- Knee-chest position
- IV fluid bolus
- Oxygen
- Sedation
- Beta blocker
- IV sodium bicarbonate
What is the initial management of transposition of the great arteries?
What is the definitive repair?
Initial: PGE to improve oxygen saturation by keeping the ductus patent or emergent balloon atrial septostomy (increases size of ASD or PFO)
Definitive repair: Arterial switch operation
What is tricuspid atresia? What is always present?
A plate of tissue located in the floor of the right atrium in the location of the tricuspid valve
An ASD or PFO is always present
In tricuspid atresia what is the significance of a VSD?
Whether or not a VSD is also present determines the direction of blood flow, the presence of other anatomic features, and the degree of stenosis
In Tricuspid atreisa, if no VSD is present and the ventricular septum is intact ______ _______ is also present; For blood to flow to the lungs in this situation, a ___ must also be present
Pulmonary atresia; PDA
What is seens on ECG in tricuspid atresia?
Right atrial enlargement, left axis deviation, and left ventricular hypertrophy
What is the management of tricuspid atresia? Describe it
The fontan procedure at 3-6 years of age
Flow from the inferior vena cava is directed into the pulmonary arteries
What other congenital heart defect is present in truncus arteriosus?
VSD
What causes the diastolic murmur in truncus arteriosus?
Diastolic murmur of flow across the mitral valve at the apex as a result of excessive pulmonary blood flow that returns to the left atrium
What is TAPVC?
Total anomalous pulmonary venous connection occurs when the pulmonary veins drain into the systemic venous side rather than into the left atrium
What are the sites of TAPVC?
- Supracardiac (into right superior vena cava or innominate vein)
- Cardiac (into right atrium or coronary sinus)
- Infracardiac (into the portal system)
What is the most common cause of acquired heart disease in children in the United States?
Worldwide?
United States: Kawasaki disease
Worldwide: Acute rheumatic fever
What are the most common bacterial agents in infective endocarditis?
Gram positive cocci, including alpha-hemolytic streptococcus (viridans) and staphylococcus species
How is infective endocarditis diagnosed?
- Blood culture is the single most important laboratory test
- Erythrocyte sedimentation rate (ESR) is usually elevated (unless polycythemia is present)
- Acute phase reactants (rhematoid factor) found in 50% of patients
- Transthoracic echocardiography detects vegitations
What are clinical signs of infective endocarditis?
- New/changing murmur
- Hematuria
- Splinter hemorrhages
- Osler’s nodes (on palms, soles, or pads of toes/fingers)
- Janeway lesions (smal, erythematous hemorragic lesions on palms or soles)
- Roth’s spots (round or oval white spots seen in the retina)
Management of infective endocarditis?
Intravenous antimicrobial therapy against identified organism for 4-6 weeks
When is antibiotic prophylaxis for endocarditis recommended?
Before invasive procedures such as dental work, gastrointestinal, or urologic surgery
Also to all postop cardiac surgery patients for up ot 6 months after surgical repair
What is the most common cause of pericarditis in children?
Viral infection
What are the most common agents of purulent pericarditis (bacterial)?
Staphylococcus aureus and streptococcus pneumoniae
What is postpericardiotomy syndrome?
Occurs in as many as 1/3 of patients whose pericardium has been opened during surgery - thought to be an autoimmune response to a concomitant viral infection
How does pericariditis lead to cardiac tamponade?
Inflammation of parietal and visceral pericardial layers leads to exudation or transudation of fluid and impairment of venous return and cardiac filling
Describe the positional changes in chest pain in pericarditis?
Chest pain most intense while supine and relieved when sitting upright
What physical exam findings are associated with pericarditis?
Pericardial friction rub, distant heart sounds, pulsus paradoxus, hepatomegaly
What is both diagnostic and therapeutic in children with pericarditis?
Pericariocentesis
What is seen on ECG in patients with large pericardial effusions?
ST-segment changes or low voltage QRS complexes
Evidence of _______ is apparent in 20% of children who die suddenly
Myocarditis
What viruses can cause myocarditis?
Bacteria?
Fungi?
Protozoa?
- Viruses: Enteroviruses, especially coxsackievirus
- Bacteria: Corynebacteria diphteriae, Strep. pyogenes, Staph. aureus, Mycobacterium tuberculosis
- Fungi: Candida, Cryptococcus
- Protosoa: Trypansoma cruzi
What autoimmune disease are associated with Myocarditis?
SLE, Rheumatic fever, Sarcoidosis
What labs are significant in myocarditis?
- Elevated ESR
- Creatinine kinase (CK) MB fraction
- C-reactive protein
- Viral serology or PCR of endomyocardial biopsy specimens
Echocardiogram of myocarditis shows an anatomically ______ heart
normal
What management may be beneficial for myocarditis patients with CHF refractory to medical management?
Cardiac transplantation
What are the three types of cardiomyopathy?
- Dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Restrictive cardiomyopathy
What are some causes of dilated cardiomyopathy?
- Viral myocarditis
- Mitochondrial abnormalities
- Carnitine deficiency
- Nutritional deficiency (such as selenium and thiamine deficiency)
- Hypocalcemia
- Medications (doxorubicin)
Evaluation of dilated cardiomyopathy should include ______ _____ and ______ ______ level
Viral serologies; serum carnitine
What is ALCAPA? How does it cause dilated cardiomyopathy?
Anomalous origin of left coronary artery from the pulmonary artery
Results in myocardial ischemia and infarction
Management of dilated cardiomyopathy?
- Medical management of CHF
- Treatment of underlying metabolic or nutritional problem
- Surgical repair of ALCAPA
- Cardiac transplantation
What is the genetic inheritence of hypertrophic cardiomyopathy?
Autosomal dominant in 60% of cases
What causes left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy?
Caused by the anterior mitral leaflet being swept into the subaortic region during systole
What is the most common cause of sudden death in athletes?
Hypertrophic cardiomyopathy
What type of murmur is associated with hypertrophic cardiomyopathy? What accenuates it?
Harsh, systolic ejection murmur at the apex - accenuated with physiologic maneuvers that reduce left ventricular volume such as Valsalva or standing
Beta-adrenergic blockers or ______ _______ blockers reduce the LVOT obstruction in hypertrophic cardiomyopathy
calcium-channel
What is the benefit of dual chamber pacing in hypertrophic cardiomyopathy?
Has been shown to reduce septal hypertrophy and LVOT obstruction in some studies
What is restrictive cardiomyopathy?
Excessively rigid ventricular walls that impair normal diastolic filling
What are some causes of restrictive cardiomyopathy?
- Amyloidosis
- Inherited infiltrative disorders (fabry disease, gaucher disease, hemosiderosis, hemochromatosis)
What causes edema, hepatomegaly, and ascites in restrictive cardiomyopathy?
Elevated central venous pressure (CVP)
What is SVT?
Abnormally accelerated heart rhythm that originates proximal to bundle of His
What is the most common dysrhythmia in childhood?
SVT
What are the two types of SVT?
Atrioventricular re-entrant tachycardia (AVRT) - retrograde conduction through accessory pathway leads to SVT
Atrioventricular node re-entrant tachycardia (AVNRT) - Conduction abnormality occurs in different pathways within the AV node itself
What is the syndrome of anterograde conduction though a bypass tract between the atria and ventricles?
Wolff-Parkinson-White (associated with sudden cardiac death)
WPW may be identified on ECG by the presence of a _____ wave
delta
What is the management of supraventricular tachycardia?
- Vagal maneuvers
- Ice pack to teh face
- IV adenosine
- Cardioversion in patients who are hemodynamically stable
- Medical management (digoxin or propanolol)
- Catheter ablation
Describe the following:
- 1st degree heart block:
- 2nd degree heart block
- Type 1:
- Type 2:
- 3rd degree heart block:
- 1st degree: prolongation of PR interval
- 2nd degree
- Type 1: Progressive prolongation of PR interval leading to failed AV conduction
- Type 2: Abrupt failure of AV conduction
- 3rd degree: Complete block with not conduction of atrial impulses to the ventricles
Management of AV block?
Pace maker
Long QT syndrome increases the risk of lethal ventricular arrhythmias known as…
torsades de pointes
What is the most common presenting sign of long QT syndrome?
Syncope
Diagnosis of long QT syndrome is based on the QTc interval which is calculated by…
Taking the measurement of the QT interval divided by the square root of the previous RR interval (>0.44 seconds)
What is the treatment of long QT syndrome?
- Beta blocker to reduce symptoms
- Treatment of asymptomatic individuals in controversial
What is the most common cause of cardiac chest pain?
Pericarditis
What are some causes of noncardiac chest pain?
Asthma, esophagitis, and costochondritis
