External Isovolumic Contraction Times and Left Ventricular Ejection Time/External Isovolumic Contraction Time Ratios at Rest and After Exercise in Coronary Heart Disease
Twenty-one men with coronary heart disease had supine phonocardiograms and carotid pulse tracings at rest, immediately after upright bicycle exercise, and 3 min after exercise 1 day preceding left ventricular cineangiography. External isovolumic contraction times (EICT) and left ventricular ejection time/EICT (LVET/EICT) ratios were computed and correlated with ejection fractions and ventricular end-diastolic volumes determined from right anterior oblique cineangiograms. For the ejection fraction, the highest correlations were with the LVET/EICT ratios immediately after (r = 0.71) and 3 min after exercise (r = 0.69). For the end-diastolic volume, the highest correlations were with the LVET/EICT ratios immediately after (r = –0.79) and 3 min after exercise (r = –0.80). The LVET/EICT ratio immediately after exercise differentiated between 13 patients with an ejection fraction of 50% or greater and eight patients with an ejection fraction <50%. These data indicate that the LVET/EICT ratio after exercise is a good noninvasive measurement for assessment of myocardial contractility.
- Received July 14, 1970.
- Accepted August 31, 1970.
- © 1971 American Heart Association, Inc.