Eccentric May Differ From Concentric Left Ventricular Hypertrophy Because of Variations in Cardiomyocyte Numbers

Abstract

BackgroundWhen overweight or hypertension is present, some patients at first examination exhibit left ventricular (LV) dilation and others concentric hypertrophy that persists indefinitely. Perhaps the ventricles with the fewest myocytes could enter systolic dysfunction with dilation and those with more myocytes may sustain persistent concentric hypertrophy. Methods and ResultsCardiomyocyte numbers, MyN, were counted in paraffin sections of left ventricles from 99 forensic autopsies, excluding instances of coronary heart disease. MyN lacked statistically significant relationships with age, race, sex, height, weight, LV mass, and mean arterial pressure estimated from renal histology. Specimens with the fewest myocytes, however, did manifest significant dilation and thinner chamber walls. ConclusionsThe tendency toward an eccentric pattern of hypertrophy in ventricles with the fewest myocytes is a clear conclusion, but has an ambiguous interpretation. This is the pattern expected from the initial hypothesis, but it also has other possible explanations. This ambiguity arises chiefly from limitations in the methods used for estimating MyN. These limitations are accessible to control in future studies. Our findings failed to contradict the hypothesis introduced here. These conclusions are implicit in the underlying observations of MyN constancy across such groupings as sex, height, weight, and LV mass, which provide the less speculative findings.