Katsutoshi Abe

Cardiac Hypertrophy in Early Hypertension

Studies of cardiac hypertrophy in spontaneously hypertensive rats have indicated that left ventricular hypertrophy occurred even in the prehypertensive stage. These findings suggested that other factors besides blood pressure levels, and including possibly a genetic predisposition to myocardial hypertrophy, could play a role in structural cardiovascular alterations in spontaneously hypertensive rats. More recent studies have confirmed these anatomic results; left ventricular hypertrophy was vectorcardiographically detected even in the prehypertensive stage in voth young stroke-prone rats and stroke-resistant spontaneously hypertensive rats. Further, a close relation was found between degree of left ventricular hypertrophy and vascular hypertrophy or hyperplasia; this suggests that early detection of left ventricular hypertrophy may be a useful indicator of the incipient stage of structural vascular changes in genetic hypertension.

A longitudinal study of blood pressure, cholesterol and left ventricular muscle volume in children: The Shimane Heart Study

Three hundred and forty‐four healthy schoolchildren living in Izumo City, Shimane Prefecture, Japan, were assessed at 3 year intervals from 6 to 15 years, starting in 1978 (Cohort 1) or 1981 (Cohort 2). Tracking indices (Ti) were calculated as follows: Ti = (2x + y ‐ z)/N/0.89, where x, y and z refer to the total number in the same, adjacent and remote trisections, respectively, and N = x + y + z. If Ti > 1, there is positive tracking. For systolic blood pressure (SBP) measurements (except at 6 years old) and serum cholesterol levels, all Ti were greater than 1.0 regardless of the time when tracking was commenced. Tracking indices were slightly greater in the serum cholesterol levels than in the SBP measurements. Left ventricular muscle volume indices (LVMVI) were calculated by echocardiographic measurements. In girls, the LVMVI was larger only in the above‐median SBP group at the age of 12 years (P < 0.01), but the LVMVI of the higher SBP (above median) group was larger than in the lower (below median) group at every age in boys; the difference was statistically significant (P < 0.05) at 12 and 15 years of age. Left ventricular mass enlargement may occur in the prehypertensive stage in humans as well as in rats.