Relation of twelve-lead electrocardiographic T-wave morphology descriptors to left ventricular mass

Abstract

Echocardiographically detected left ventricular (LV) hypertrophy is an independent risk factor for sudden cardiac death, and the relative risk increases as LV mass increases. 1 Experimental studies strongly suggest that development of LV hypertrophy creates arrhythmia-generating repolarization abnormalities. 2‐6 The inscription of the T wave on the body surface electrocardiogram (ECG) is generated by repolarization gradients at the myocardial level. 7,8 A change in these gradients has an effect on T-wave morphology. 7‐10 Thus, repolarization gradients, arrhythmic vulnerability, and T-wave morphology are interrelated. 8,11 Recently, novel T-wave morphology descriptors on the 12-lead ECG 12 were shown to carry important prognostic information on arrhythmic susceptibility in patients with coronary artery disease. 13,14 We examined whether T-wave morphology descriptors are associated with echocardiographically determined LV hypertrophy and correlate with the degree of LV hypertrophy. ••• We studied 50 subjects who participated in an ongoing study examining the capability of body surface mapping techniques to detect LV hypertrophy. The LV hypertrophy group (n 35) consisted of 24 patients with hemodynamically significant aortic stenosis and 11 patients with essential arterial hypertension, all of whom had echocardiographic LV hypertrophy by gender-specific criteria (LV mass indexed to body surface area 116 g/m 2 in men; 104 g/m 2 in women). 15 No patient had echocardiographic wall motion abnormalities or pathologic Q waves on the ECG. In addition, no patient with aortic stenosis had 70% stenosis of the luminal diameter in epicardial arteries on routine coronary angiography, and no patient with essential hypertension had a history of effort angina. The control group consisted of 15 healthy middleaged volunteers who had no cardiovascular risk factors or a history or signs of heart disease. In these 15 subjects, a screening echocardiogram showed no evidence of anatomic or valvular abnormalities, and a symptom-limited exercise test without ST-segment