Prolonged Tpeak-to-tend interval on the resting ECG is associated with increased risk of sudden cardiac death

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.

Figure 1

1A. Box plot of distribution of TpTe interval among cases and controls (TpTe, Tpeak to Tend interval) 1B. Distribution of TpTe interval among cases and controls Bar diagram showing relative clustering of cases towards the higher values of TpTe. Above the interval range 95-104.9ms of TpTe, ≥80% are cases. (TpTe, Tpeak to Tend interval)

Figure 1

1A. Box plot of distribution of TpTe interval among cases and controls (TpTe, Tpeak to Tend interval) 1B. Distribution of TpTe interval among cases and controls Bar diagram showing relative clustering of cases towards the higher values of TpTe. Above the interval range 95-104.9ms of TpTe, ≥80% are cases. (TpTe, Tpeak to Tend interval)

Figure 2

Receiver operating characteristic (ROC) curve for comparing TpTe, QTc and QRSD. The area of the ROC curves were 0.73 for TpTe, 0.68 for QTc and 0.53 for QRSD. (TpTe, TpTe interval; QTc, QTc interval; QRSD, QRS duration).