T-loop morphology as a marker of cardiac events in the elderly

ST-T wave changes of electrocardiographic (ECG) leads have long been recogn ized as predictors of future cardiac events, but they only imperfectly char acterize T-loop morphology. Using vectorcardiographic (VCG) parameters, we investigated the predictive value of T-loop abnormality for fatal and nonfa tal cardiac events in a prospective cohort study among 5,815 elderly. Separ ately, the predictive value of an easily obtainable T-loop parameter, the T axis, was also assessed. Measurements were determined by a computer progra m, using VCGs reconstructed from the standard 12-lead ECGs. During the 3 to 6 (mean 4) years of follow-up, 166 fatal and 193 nonfatal cardiac events o ccurred. Subjects with an abnormal T-loop morphology had increased risks fo r fatal cardiac events (hazard ratio 4.3; 95% CI 3.0-6.4) and nonfatal card iac events (3.0; 1.9-4.8). Risks associated with an abnormal T axis alone w ere only slightly lower. Additional adjustment for established cardiovascul ar risk indicators resulted in lower, but still highly significant risks. B oth T-loop and T-axis abnormalities appear to be strong, independent risk i ndicators of cardiac events in the elderly.