Cardiomyocyte size estimated from noninvasive measurements of left ventricular wall thickness and chamber diameter.

Noninvasive measurements of left ventricular wall thickness (LVT) and left ventricular chamber diameter (LVD) allow calculation of expected left ventricular weight (LVW), but not of myocyte breadth (MyB), so that specification of left ventricular hypertrophy (LVH) is not optimal. Hypertrophied hearts, excluding coronary heart disease, and comparison specimens without hypertrophy were compiled into a series of 78 forensic autopsies, wherein LVT, LVD, and LVW were measured. MyB was measured in hematoxylin and eosin-stained paraffin sections. A series of clinical cases tabulating LVD and LVT was assembled from readily available publications. From postmortem data, a regression equation was derived to predict MyB from LVD and LVT. Applying this equation to the clinical data produced a scatter plot closely resembling that in the postmortem dataset. The equation derived here appears to provide valid predictions of cardiomyocyte sizes expected in histological measurements. The finding is the first of its kind and requires further testing for validation or rejection. This is offered as a provisional way to improve the determination of LVH using noninvasive measurements. How this improvement might enhance understanding of the mechanisms for hypertrophy is briefly explored, thus generating working hypotheses.