Pacemaker-Induced Change in Prosthetic Valvular Sounds

Abstract

Variable intensity and timing of valvular sounds were noted in two patients with permanent pacemakers and prosthetic valves. In the first patient, who had a mitral and a tricuspid prosthesis, valvular opening sounds became widely separated with a change from nodal to ventricular paced rhythm. In a second patient, who had a mitral prosthesis in sinus rhythm with first-degree atrioventricular block, a very quiet closing sound increased markedly in intensity with the onset of ventricular pacing. The mechanism for these changes is described using a technique which at brief intervals throughout the cardiac cycle permitted documentation of simultaneously recorded phonocardiogram, electrocardiogram, and pulse tracings with a visible image of the prosthesis. In the usual patient with a prosthetic valve auscultatory changes should arouse a suspicion of malfunction; however, in the relatively uncommon patient with a prosthesis and an artificial pacemaker, it should be recognized that auscultatory changes may well have a physiologic explanation.