Snapshot A 20-year-old woman with a history of a childhood heart murmur presents for multiple syncopal episodes. She reports feeling constantly fatigued and has shortness of breath with exertion, even with minor physical activity. Physical exam reveals clubbing of the fingers and 2+ pitting edema bilaterally on the lower extremities. An electrocardiogram reveals right heart hypertrophy. An echocardiogram and right heart catheterization are scheduled. Introduction Clinical definition uncorrected left-to-right shunting, often caused by congenital heart defect, leading to pulmonary arterial hypertension (PAH) and right ventricular hypertrophy (RVH) Etiology Ventricular septal defect Atrial septal defect Patent ductus arteriosus Pathogenesis left-to-right shunting from a congenital heart defect can cause increased pulmonary blood flow irreversible changes in the pulmonary vasculature → PAH normal pulmonary artery pressures are 10-14 mmHg pulmonary hypertension occurs when pressures are ≥ 25 mmHg RVH develops in compensation → shunting reverse in blood flow to become right-to-left → cyanosis and respiratory distress clinically, this results in secondary erythrocytosis, thrombocytopenia, and immune dysfunction Epidemiology Risk factors congenital heart defect Presentation Symptoms shortness of breath syncope chest pain hemoptysis exercise intolerance Physical exam edema cyanosis of lips, oral mucosa, or extremities cardiac exam high-pitched early diastolic murmur pulmonary insufficiency jugular venous distension loud pulmonary component of S2 sound clubbing of extremities peripheral edema Imaging Radiography indication performed to exclude lung diseases views chest findings right ventricular enlargement dilated pulmonary arteries loss of peripheral blood vessels increased hilar vasculature markings Doppler echocardiography indications for all patients to estimate pulmonary pressures findings visualization of shunt Studies Labs complete blood count ↑ hematocrit and hemoglobin ↓ MCV iron studies ↑ TIBC ↓ serum ferritin ↓ Fe2+ Electrocardiogram (ECG) findings right heart hypertrophy Right heart catheterization indication to confirm diagnosis findings mean pulmonary arterial pressure at least 25 mmHg at rest Making the diagnosis based on clinical presentation and imaging Differential Interstitial lung disease causing pulmonary hypertension distinguishing factor chest radiograph typically shows signs of interstitial fibrosis, such as a honeycomb or cystic appearance Treatment Management approach includes pulmonary vasodilatory therapy, management of erythrocytosis, and management of complications Conservative avoid overexertion with physical activities indication all patients Medical diuretics indication patients with signs of right heart failure and fluid retention vasodilatory therapies indications for patients with PAH drugs endothelin receptor antagonists bosentan ambrisentan phosphodiesterase inhibitors tadalafil sildenafil Operative lung and heart transplant indication end-stage disease refractory to medical management Complications Heart failure End-organ damage from hyperviscosity of erythrocytosis Prognosis Age of onset depends on type and severity of defect Can present as early as childhood Death can result from decompensated cor pulmonale