Physical Signs, Apexcardiography, Phonocardiography, and Systolic Time Intervals in Angina Pectoris
Coronary artery disease and angina pectoris are frequently associated with disordered myocardial function which may cause abnormalities in precordial motion, heart sounds, and/or systolic time intervals. The pathophysiologic basis for these abnormalities has been studied by correlating them with more direct measurements of myocardial function. Large a waves on the apexcardiogram and atrial gallops are related to accentuated left ventricular a waves which reflect diminished left ventricular compliance. Uncoordinated left ventricular contraction (asynergy) may cause abnormal systolic motion which can sometimes be recorded on the apexcardiogram. Ventricular (early diastolic) gallops in coronary artery disease are usually associated with extensive obstructive lesions, left ventricular asynergy, and a low cardiac output. Transient paradoxic splitting of the second sound in angina pectoris has been reported though rarely documented by phono-cardiography. Mitral insufficiency due to papillary muscle dysfunction implies significant damage to the papillary muscles and the surrounding ventricular wall, usually by severe coronary artery disease. Systolic time intervals are a sensitive technic which may reflect diminished contractility (prolonged preejection period) or low stroke volume (shortened left ventricular ejection time) in patients with coronary artery disease. However, systolic time intervals are also sensitive to many other pharmacologic and hemodynamic influences, including changes in left ventricular preload and afterload which may result in misleading values. Therefore, as a technic for evaluating individual patients with coronary artery disease and angina pectoris, the role of systolic time intervals remains limited.
- © 1972 American Heart Association, Inc.