A study on the pattern of myocardial distribution and its relationship to the genesis of giant negative T wave in patients with hypertrophic cardiomyopathy
Anzai, T.
Hokkaido Journal of Medical Science 65(2): 170-177
1990
ISSN/ISBN: 0367-6102 PMID: 2365275 Document Number: 365928
Quantitative measurements of cardiac mass were performed in patients (pts) with hypertrophic cardiomyopathy (HCM) to assess the relationship between the pattern of myocardial distribution and the degree of T wave inversion on the electrocardiogram. Thirty-three pts with HCM (10: apical hypertrophy, 18: non-obstructive, 5: obstrucive) and 10 age-matched normal subjects were studied. Electrocardiographically triggered X-ray computed tomographic scannings were obtained from apex to base of the left ventricle. Left ventricular apex/septum wall thickness ratio (Ta/Ts), left ventricular apex/base mass ratio (Ma/Mb) and total left ventricular mass (LVM) were measured at end-diastole. In 61% of the pts the electrocardiogram showed giant negative T wave (GNT: defined as greater than 1mV). All pts with apical hypertrophy had GNT, however GNT was observed only in 44% of non-obstructive and in 40% of obstructive pts. Both Ta/Ts and Ma/Mb were significantly greater in pts with GNT than those without GNT (1.34 .+-. 0.40 vs 0.66 .+-. 0.21, p < 0.001, 1.65 .+-. 0.28 vs. 1.28 .+-. 0.17, p < 0.001) and normal controls (1.34 .+-. 0.40 vs. 0.99 .+-. 0.17, p < 0.01, 1.65 .+-. 0.28 vs. 1.28 .+-. 0.11, p < 0.001), while LVM was significantly increased in pts without GNT than those with GNT (191.4 .+-. 57.0 vs 139.4 .+-. 39. 2, p < 0.01) and normal controls (191.4 .+-. 57.0 vs 97/2 .+-. 13.9, p < 0.001). The amplitude of negative T wave showed a positive correlation with Ta/Ts and Ma/Mb (r = 0.624, p < 0.001, r = 0.566, p < 0.001, respectively) and negative correlation with LVM (r= -0.466, p < 0.01) in pts with HCM. These findings suggest that an asymmetrical distribution of left ventricular hypertrophy localized to the apical region is associated with the development of GNT and a concomitant hypertrophy in the besal region decreases the magnitude of T wave inversion.