pulsus parvus et tardus

In severe aortic stenosis, the narrowed valve orifice impedes left ventricular outflow, causing both a diminished amplitude of the arterial pulse (parvus) and a delayed, slow-rising upstroke (tardus) as blood is ejected more slowly through the narrowed valve. This is best appreciated by palpating the carotid artery. On physical exam, this finding is often accompanied by a harsh crescendo-decrescendo systolic murmur radiating to the carotids, a soft or absent S2 (due to reduced mobility of calcified valve leaflets), and possibly an S4 gallop from left ventricular hypertrophy. Pulsus parvus et tardus is a key clinical clue distinguishing severe aortic stenosis from other causes of systolic murmurs (e.g., aortic sclerosis, which does not significantly obstruct flow and thus does not produce this finding). It is important to differentiate this from pulsus parvus in other low-output states (e.g., severe heart failure) and from pulsus bisferiens (seen in mixed aortic valve disease or hypertrophic cardiomyopathy). Doppler echocardiography is used to confirm severity by measuring the aortic valve area, mean gradient, and peak velocity across the valve. Clinically, pulsus parvus et tardus in a patient with a systolic murmur should raise concern for symptomatic severe aortic stenosis, which may warrant valve replacement (surgical or transcatheter aortic valve replacement) if the patient develops symptoms such as angina, syncope, or heart failure (the classic triad).