From Ask Dr Wiki
General Epidemiology about Birth Defects
- About 120,000 babies (1 in 33) in the United States are born each year with birth defects (most common is Down’s syndrome)
- ~ 1% (8 / 1000) live births have Congenital heart disease
- > 1 million American adults
- > 1 million American children
Different types of Congenital Heart Disease
- VSD (most common anomaly: 20-25% of all Congenital heart disease
- ASD: 5-10% (most common adult lesion)
- Ostium primum: lower part of atria: closer to the valves (usu MV)
- Ostium secundum
- Sinus venosus
- Patent Ductus Arteriosus (PDA) - 10% of all Congenital heart disease [PDA is a connection between the aorta and the pulmonary artery: (Normally this closes within a few hours of birth)]
- Atrioventricular canal defect (AV canal) - a complex heart problem that involves several abnormalities of structures inside the heart, including an ASD, VSD, and improperly formed mitral and/or tricuspid valves.
- Total or partial anomalous pulm venous return
- Truncus arterious (only one artery arises from the heart and forms the aorta and pulmonary artery)
- Single ventricle
- Transposition of the great arteries (1900 / year): 4%
- Tetralogy of Fallot: is characterized by VSD, overriding aorta, RVH, pulmonary stenosis (6%)
- Coarctation of the aorta: 7%
- Aortic Stenosis: 6%
- In 1897, Dr Victor Eisenmenger (Austrian) reported the case of a 32-yo ♂: exercise intolerance, cyanosis, HF, and hemoptysis prior to death.
- Autopsy showed a large VSD and overriding aorta.
- This was the first description of a link between a large congenital cardiac shunt defect and the development of pulmonary hypertension.
- An underlying heart defect that allows blood to pass between the left and right sides of the heart.
- Pulmonary hypertension
- Reversal of the shunt
(Eisenmenger syndrome constituted 8% of all congenital heart disease in 1950’s, but because of early detection and treatment of cardiac defects, its incidence dropped down to 4%.
Sequence of events in Eisenmenger syndrome
- Congenital left to Right shunt
- Increased flow and pressure in the pulm vasculature
- Pulmonary capillary destruction / scarring and pulmonary arteries thickening and endothelial dysfunction
- Increased pulm artery pressure
- RV hypertrphy (…ischemia / arrhythmia)
- Increased RV pressure à more than LV pressure
- Reversal of shunt from Rt à Lt…… Cyanosis …Polycythemia …..hyperviscosity …. CVA / PE
Morphologic changes of pulmonary artery vasculature include:
- Initial morphologic alterations (potentially reversible) are:
- Medial hypertrophy
- Intimal proliferation and fibrosis
- Occlusion of cappilaries and small arterioles
- Advanced irreversible changes:
- Plexiform lesions
- Necrotizing arteritis
- Result = obliteration of much of the pulmonary vascular bed ↑ Pulmonary vascular resistance
- Dyspnea on exertion (most common symptom)
- Afib / flutter: 35%
- V-tach 10%
- Fluid overload
- Chest pain, syncope (due to ↓ Cardiac output or arrhythmia), fatigue
- Erythrocytosis (2˚ to hypoxia) hyperviscosity (fatigue, h/a, visual disturbances, dizziness, and paresthesias)
- Hemoptysis (due to pulmonary infarction or rupture of dilated pulmonary vessels)
- Cholelithiasis, nephrolithiasis
- Hypertrophic arthropathy
- Slowed mentation / Decreased alertness
- Arterial pulses are small in volume
- Jugular venous pulse wave may be A-wave dominant. However, with tricuspid regurgitation, the V wave may be prominent.
- Precordial palpation reveals a right ventricular heave and, frequently, a palpable S2.
- Loud P2
- High-pitched early diastolic murmur of pulmonic insufficiency
- Right-sided fourth heart sound
- Pulmonary ejection click
- A fixed, widely split S2 is characteristic of an ASD pansystolic murmur of tricuspid regurgitation.
- The murmur of ASD or VSD, and the continuous murmur of a PDA disappear when Eisenmenger physiology develops; a short systolic murmur may remain audible
- Respiratory signs include cyanosis and tachypnea. (usu clear lungs)
- Hematologic signs include bruising and bleeding; funduscopic abnormalities related to erythrocytosis include engorged vessels, papilledema, microaneurysms, and blot hemorrhages.
- Abdominal signs include jaundice, right upper quadrant tenderness, and positive Murphy sign (acute cholecystitis).
- Vascular signs include postural hypotension and focal ischaemia (paradoxical embolus).
- Musculoskeletal signs include clubbing, tenderness over the metacarpal or metatarsal joints (hypertrophic osteoarthropathy), and joint effusions.
- Peaked P waves
- +/- atrial arrhythmias
- Echo with Doppler ultrasound can diagnose the direction of the shunt
- Cardiac catheterization with ‘step up’ oxygen measurements
- In early childhood, surgical intervention can repair the heart defect, preventing most of the pathogenesis of Eisenmenger's syndrome.
- If treatment has not taken place, heart-lung transplant is required to fully treat the syndrome.
- If this option is not available, then Eisenmenger syndrome is treated just like any other pulmonary arterial (aka primary or pre-capillary) hypertension. This treatment is usually includes prostacyclines (prototype is Epoprostenol), endothelin recptor antagonists ( Bosentan or Ambrisentan), PDE5 inhibitors (prototype is sildenafil), in addition to anticoagulation.
- Antibiotic prophylaxis to prevent endocarditis and phlebotomy to treat polycythemia may also indicated.Antibiotic prophylaxis to prevent endocarditis and phlebotomy to treat polycythemia may also indicated.
Causes of death
- Sudden Cardiac Death (30%)
- Heart failuire (25%)
- Hemoptysis (15%)
- Pregnancy, peri-op, & infections (brain abscess or endocarditis): (~25-30%)
Take home message
- Best tx is detection of shunt early, and prevention of reversal of shunt.