What did an upward-pointing T wave in ECG lead aVR reveal about cardiovascular mortality?

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Because it was unclear which of the 12 ECG leads provides the most information, researchers investigated the association between repolarization in all 12 leads and cardiovascular mortality. They conducted a retrospective cohort study at Palo Alto Veterans Affairs Medical Center in Palo Alto, California, including 24,270 consecutive male veterans whose ECGs were obtained for clinical reasons from 1987 to 2000. They analyzed computerized 12-lead resting ECGs, excluding inpatients and patients with atrial fibrillation, WPW, QRS duration greater than 120 ms, or paced rhythms. Average follow-up was 7.5 years, during which 1,859 cardiovascular deaths occurred.

ST segment measurements in aVR predicted cardiovascular death in univariate analysis, but T wave amplitude superseded them in multivariate survival analysis. T wave amplitude in aVR also outperformed repolarization measurements in all other leads and other ECG criteria, including Q waves, damage scores, and left ventricular hypertrophy (LVH), for predicting cardiovascular mortality. As T wave amplitude in aVR became less negative, relative risk progressively increased. When the aVR T wave had a positive, upward deflection, the relative risk of cardiovascular death was 5.0.

The researchers concluded that T wave amplitude in lead aVR is a powerful prognostic marker for estimating cardiovascular death risk. Upward-pointing T waves, a simple visual criterion, were present in 7.3% of the clinical population and were associated with annual cardiovascular mortality of 3.4% and a fivefold risk.