Abstract
Giant negative T wave was observed electrocardiographically in 25 subjects without hypertension and 10 with hypertension. In addition to these, 20normal controls were selected, and echocardiography was undertaken. The diagnostic criteria of asymmetrical septal hypertrophy (ASH) are interventricular septal wall thickness of 15mm or more and interventricular septal wall thickness : left ventricular posterior wall thickness ratio of 1.3 at the cardiac base. The differences of cardiac function among the apical hypertrophy group (APH group) comprising 14 cases, the group with asymmetrical septal hypertrophy with apical hypertrophy (ASH with APH) comprising II cases and hypertensive subjects having ASH-with-APH pattern comprising 10 cases were compared with each other. Furthermore, 8cases in the APH group, 10 cases in the ASH-with-APH group, 9 cases with hypertension and 20 controls were selected for further study. Total area, muscle area and cavity area were calculated from the tomographic short axis view of LV at the end-diastolic phase with Digitizer Apple II microcomputer. These areas were then photographed with Polaroid film at the level of the chorda tendinea (base), the tip level of the papillary muscle (middle) and the basal level of the papillary muscle (apex). The ratios among these areas were ascertained for evaluating the relationships among the shortening degree of the left ventricular cavity, the difference of the left ventricular wall thickness from the cardiac base to the apex and the depth of the giant negative T wave. The GNT group showed a significant degree of left ventricular cavity shortening from the cardiac base to the apex, particularly in the ASH-with-APH group. The relationship between the apex : base muscle area ratio and the deepest GNT (mm) /the voltage of the R wave (mv) of the same lead was evaluated. The significant result that Y=2.39×+0.593, r=0.68, n=18, p<0.01 shows a positive correlation between the depth of the GNT wave corrected by its R wave voltage (mv) and the apex : base muscle area ratio. The enlargement of the apical muscle area in the APH and ASH with APH groups was due to hypertrophy of the interventricular septum, the free wall and the papillary muscle, mainly the latter.
