Abstract
BACKGROUND: Early studies indicate that prolongation of the interval between the peak and the end of the T wave (Tpeak to Tend [TpTe]) on the 12-lead ECG is a marker of ventricular arrhythmogenesis. However, community-based studies have not been conducted. METHODS AND RESULTS: TpTe and other ECG predictors were evaluated in the ongoing Oregon Sudden Unexpected Death Study based in the Portland, Oregon, metropolitan area using a case-control design. Cases of sudden cardiac death (SCD) (n = 353; mean age, 66.6 years; 95% CI, 65.1 to 68.1 years; 67% men) were compared with living controls with coronary artery disease (n = 342; mean age, 64.7 years; 95% CI, 63.4 to 66.0 years; 69% men) from the same region. Analysis of TpTe and selected ECG intervals was limited to sinus rhythm 12-lead ECGs. For cases, these were obtained before and unrelated to SCD. Independent-samples t tests and multiple logistic regression were used. Mean TpTe was significantly greater in cases (89.4 ms; 95% CI, 87.7 to 91.2 ms; P < 0.0001) than in controls (76.1 ms; 95% CI, 74.8 to 77.4 ms). The other ECG intervals (corrected QT interval [QTc], QRS duration [QRSD], and TpTe/QT ratio) also were significantly prolonged among cases versus controls (P ≤ 0.01). TpTe remained a significant predictor of SCD after adjusting for age, sex, QTc, QRSD, and left ventricular function. Odds of SCD increased more with a 1-SD increase in TpTe (12 ms) among subjects with prolonged QRSD (odds ratio, 3.49; 95% CI, 2.06 to 5.91) than with a 1-SD increase in TpTe among subjects with normal QRSD (odds ratio, 1.96; 95% CI, 1.65 to 2.32). TpTe remained significantly associated with SCD in subjects with normal QTc. CONCLUSIONS: Prolongation of the TpTe interval measured in lead V5 was independently associated with SCD, with particular utility when the QTc was normal or not measurable because of prolonged QRSD.