Assessing the severity of aortic stenosis by phonocardiography and external carotid pulse recordings.

Phonocardiograms and carotid pulse tracings were done on a group of 47 patients with all degrees of aortic stenosis and were compared with two groups of normals. Indices evaluated were pre-ejection period, left ventricular ejection time, maximum rate of arterial pulse rise, arterial half rise time (T time) and upstroke time, and timing of the peak intensity of the systolic murmur in relation to the electrocardiographic QRS and first heart sound. The indices most indicative of the presence of aortic stenosis and best correlated with its severity were the ejection time index, the maximal rate of rise of the carotid pulse and the timing of the peak of the systolic murmur. If, in a given case, all three of these indices fall outside of certain limits (ejection time index >0.42 sec, maximum rate of arterial pulse rise <500 mm Hg/sec, and Q wave to peak of murmur >0.19 sec), then severe aortic stenosis is almost invariably present.