Pacemaker-induced friction rub and apical thrill.

A patient with acute myocardial infarction developed a loud systolic sound and apical thrill. Doppler ultrasound excluded interventricular septal rupture and significant mitral or tricuspid regurgitation. Auscultatory abnormalities disappeared after removal of a temporary pacing electrode, suggesting that the friction it created with intracardiac structures was responsible for these findings.