The Significance of the Intensity and Time of Appearance of the Korotkoff Sounds in

Aside from their value in the indirect determination of the blood pressure the sounds at the brachial artery provide other valuable clinical information. Their value in blood pressure determination in auricular fibrillation generally has been found to be limited. By using a simple technic involving the counting of the brachial-artery-sound deficit, a satisfactory, repeatable method of blood pressure estimation is achieved in such patients with marked pulse rate irregularities. Other information, including a rough estimation of left ventricular stroke output, pulse wave force and velocity, are also appraised by analysis of these bruits. ASIDE from their common use for estimation of the blood pressure level,' the Korotkoff sounds also provide other useful clinical information. Thus, the intensity and duration of the sounds provide an appraisal of the volume of blood flowing through the artery under the cuff.2 A cali-brated contour of the upstroke of the pulse wave, as well as an estimate of the celerity of its transmission rate, can also be established.3 The present study provides evidence that the time of onset of the sounds during the cardiac cycle is related to the diastolic filling time. In auricular fibrillation the determination of the incidence of the sounds at various cuff pressure levels permits a satisfactory measure of the blood pressure level despite irregularities of the pulse. METHODS The sounds at the brachial artery were recorded simultaneously with lead II of the electrocardio-gram in seven patients with auricular fibrillation. The pressure in the sphygmomanometer cuff was first raised to levels higher than systolic in order t