diastolic murmur

Diastolic murmurs arise from abnormal blood flow during ventricular relaxation and filling. Unlike many systolic murmurs (e.g., physiologic flow murmurs), diastolic murmurs are almost always pathologic and warrant further workup (echocardiography).

Key types: 1. Early diastolic, decrescendo, high-pitched murmurs: Aortic regurgitation (heard best at left sternal border, patient leaning forward, causes include bicuspid valve, endocarditis, aortic root dilation/Marfan, rheumatic disease) and Pulmonic regurgitation (Graham Steell murmur, associated with pulmonary hypertension). 2. Mid-to-late diastolic, low-pitched rumbling murmurs: Mitral stenosis (heard best at apex with bell in left lateral decubitus position, often due to rheumatic heart disease, may have opening snap after S2, associated with left atrial enlargement and atrial fibrillation) and Tricuspid stenosis (rare, increases with inspiration). 3. Austin Flint murmur: a mid-diastolic rumble at the apex caused by severe aortic regurgitation jet interfering with mitral valve opening—mimics mitral stenosis but without an opening snap.

Clinical significance: Diastolic murmurs indicate underlying structural valve disease and are associated with significant morbidity if untreated (heart failure, atrial fibrillation, embolic stroke in mitral stenosis; left ventricular volume overload and eventual failure in aortic regurgitation). Physical exam maneuvers (patient positioning, respiration, hand grip, Valsalva) help characterize and differentiate these murmurs. Echocardiography is the definitive diagnostic tool to assess valve anatomy, severity, and hemodynamic consequences.

High-yield associations for boards: Mitral stenosis - rheumatic fever, opening snap, atrial fibrillation, hemoptysis, pulmonary edema. Aortic regurgitation - wide pulse pressure, bounding pulses (water-hammer pulse), Quincke's pulses, head bobbing (de Musset sign), Marfan syndrome, endocarditis, syphilitic aortitis.