SYSTOLIC EJECTION MURMURS IN THE ERA OF MODERN CARDIOLOGY - WHAT DO WE REALLY KNOW

The basics of pulsatile ejection dynamics are reviewed in order to cla rify the relationships among left ventricular and aortic pressures, in tra-left ventricular and aortic how velocities, and cardiovascular sou nd. The principles of turbulent flow are examined using the Reynolds n umber concept, and the evidence for cause-and-effect relationships bet ween turbulent flow and mur mur generation is presented. Examples of h emodynamics and phonocardiography are given for normal subjects and ar e com pared to patients with aortic stenosis and hypertrophic cardiomy opathy. The concepts presented are used to analyze the results of a ne w study suggesting increased intraventricular velocities as a new caus e for systolic murmurs in adults. (J Am Coll Cardiol 1998;32:1596-602) (C)1998 by the American College of Cardiology.