Practical Significance of Systolic Time Intervals in Coronary Artery Disease

¹ Cardiovascular Laboratory, University of Kansas Medical Center, Kansas City

Systolic time interval measurements were compared to the left ventricular ejection fractions (LVEF) calculated from angiograms in 44 patients with chest pain to determine if left ventricular dysfunction could be predicted using this noninvasive method. Correlation of the pre-ejection phase index (PEPI) and LVEF was significant, in that a longer PEPI was associated with a low LVEF (r= —0.65). Determination of the ratio of pre-ejection period/left ventricular ejection time offered no advantage over the PEPI in determination of the LVEF (r= —0.67). Although a PEPI of 150 or greater was always associated with a low LVEF, estimation of the LVEF in any given patient could not be made with precision, using this phonocardiographic measurement; however, the use of the PEPI may have limited value in screening patients with severe ischemic heart disease.