Valvular Heart Disease

Valvular heart disease changes either the resistance to forward flow or the direction of blood flow. Stenosis narrows an opening; regurgitation allows blood to move backward when the valve should be closed. The resulting pressure or volume load is what eventually enlarges, thickens, or weakens the affected chamber. Calcific aortic stenosis illustrates the pressure-load pattern. Progressive leaflet calcification restricts opening, creating a fixed obstruction between the left ventricle and aorta. The ventricle initially compensates with concentric hypertrophy, but exertional dyspnea, angina, syncope, or heart-failure symptoms indicate that compensation is failing. The typical finding is a harsh crescendo-decrescendo systolic ejection murmur at the right second intercostal space, radiating toward the carotids. A late peak, soft or single S2, and delayed low-amplitude carotid upstroke make advanced obstruction more likely. Mitral stenosis obstructs emptying from the left atrium into the left ventricle during diastole. Rheumatic disease remains the dominant cause worldwide. Pulmonary venous congestion, atrial enlargement, atrial fibrillation, and thromboembolism follow the upstream pressure rise. Listen at the apex with the bell in the left lateral position for a loud S1, an opening...