No Association Between T-peak to T-end Interval on the Resting ECG and Long-Term Incidence of Ventricular Arrhythmias Triggering ICD Interventions

Abstract

Background and Objectives Potential of using the T-peak to T-end (TpTe) interval as an electrocardiographic parameter reflecting the transmural dispersion of ventricular repolarization (TDR) to identify patients (pts.) with higher risk of malignant ventricular arrhythmias (MVA) for better selection of candidates for implantable cardioverter-defibrillator (ICD) in primary prevention (PP) of sudden cardiac death (SCD) remains controversial. The primary objective of this study was to investigate the relationship between the TpTe interval in patient’s preimplantation resting 12-lead electrocardiogram (ECG) and the incidence of MVA resulting in appropriate ICD intervention (AI). The secondary objective was to assess its relationship to overall mortality. Methods A total of 243 consecutive pts. with severe left ventricular (LV) systolic dysfunction after myocardial infarction (MI) with a single-chamber ICD for PP of SCD from one implantation center were included. Excluded were all pts. with any other disease that could interfere with the indication of ICD implantation. Primarily investigated intervals were measured manually in accordance with accepted methodology. Data on ICD interventions were acquired from device interrogation during regular outpatient visits. Survival data were collected from the databases of health insurance and regulatory authorities. Results We did not find a significant relationship between the duration of the TpTe interval and the incidence of MVA (71.5 ms in pts. with MVA vs. 70 ms in pts. without MVA; p = 0.408). Similar results were obtained for the corrected TpTe interval (TpTec) and the ratio of TpTe to QT interval (76.3 ms vs. 76.5 ms; p = 0.539 and 0.178 vs. 0.181; p = 0.547, respectively). There was also no significant difference between the duration of TpTe, TpTec and TpTe/QT ratio in pts. groups by overall mortality (71.5 ms in the deceased group vs. 70 ms in the survivors group; HR 1.01; 95% CI, 0.99–1.02; p = 0.715, 76.3 ms vs. 76.5 ms; HR 1.01; 95% CI, 0.99–1.02; p = 0.208 and 0.178 vs. 0.186; p = 0.116, respectively). Conclusion This study suggests no significant association of overall or MVA-free survival with ECG parameters reflecting TDR (TpTe, TpTec) in patients with systolic dysfunction after MI and ICD implanted for primary prevention.

Optimizing ECG lead selection for detection of prolongation of ventricular repolarization as measured by the Tpeak-end interval

“…Furthermore, these findings were validated in an independent cohort. Interestingly, in our participants in the derivation and validation cohorts at supine rest, the maximal Tp-e was never localized in leads V5 or V6, even though these leads have been among those selected for Tp-e measurement in several studies 9,[12][13][14] , including studies that did not find an association between Tp-e length and risk of ventricular arrhythmias or sudden cardiac death 26,27 .…”

Optimizing ECG lead selection for detection of prolongation of ventricular repolarization as measured by the Tpeak‐end interval

“…Furthermore, these findings were validated in an independent cohort. Interestingly, in our participants in the derivation and validation cohorts at supine‐rest, the maximal Tp‐e was never localized in leads V5 or V6, even though these leads have been among those selected for Tp‐e measurement in several studies (Shimizu et al, 2002 ; Panikkath et al, 2011 ; Lubinski et al, 1998 ; Bachmann et al, 2016 ), including studies that did not find an association between Tp‐e length and risk of ventricular arrhythmias or sudden cardiac death (Michalek et al, 2020 ; Porthan et al, 2013 ).…”

Steep repolarization time gradients in pig hearts cause distinct changes in composite electrocardiographic T‐wave parameters

“…T peak-end has been a topic for discussion in relation to repolarization heterogeneity in recent literature (Malik et al, 2019). Studies report a relation between T peak-end and arrhythmia risk in patients with heart failure (Rosenthal et al, 2015), ischemic heart disease (Shenthar et al, 2015) and BrS (Castro Hevia et al, 2006), although other studies contradict that prolonged T peak-end interval is proarrhythmic (Michalek et al, 2020;O'Neal et al, 2017). We have previously shown that the onset of the electrocardiographic T wave occurs before first measured RT and that 75% of recording sites repolarized after T peak (Meijborg et al, 2014).…”