Age and intrinsic left ventricular myocardial contractility.

ABSTRACT

The purpose of this study was to compare the left ventricular (LV) intrinsic contractile function in normal elderly (age > or = 60 years, mean age 66 +/- 4 years) and young (age < or = 35 years, mean 27 +/- 9 years) healthy volunteers by stress-shortening and stress-length relationship using a co-variate analysis. Echocardiographically determined meridional and circumferential wall stress were plotted against LV fractional shortening, velocity of circumferential fibre shortening, end-systolic volume and diameter. LV ejection fraction, preload (denoted by end-diastolic volume) and afterload (expressed as circumferential wall stress) were similar in the two groups. Stress-shortening and stress-length relationships using the circumferential wall stress showed no difference in the two groups, although meridional wall stress was greater in the elderly population. Our results suggest that circumferential wall stress is a better method to detect intrinsic contractile abnormality in the elderly. Intrinsic LV ejection performance is within the normal range in the elderly healthy individuals.