Assessment of the relationship between reperfusion success and T-peak to T-end interval in patients with ST elevation myocardial infarction treated with percutaneous coronary intervention

Tpeak-Tend ECG Marker in Obesity and Cardiovascular Diseases: A Comprehensive Review

Globally, cardiovascular diseases are still the leading cause of death. Numerous methods are used to diagnose cardiovascular pathologies; there is still a place for straightforward and noninvasive techniques, such as electrocardiogram (ECG). Depolarization and repolarization parameters, including QT interval and its derivatives, are well studied. However, the Tpeak-Tend interval is a novel and promising ECG marker with growing evidence for its potential role in predicting malignant arrhythmias. In this review, we discuss the association between the Tpeak-Tend interval and several cardiovascular diseases, including long QT syndrome, cardiomyopathies, heart failure, myocardial infarction, and obesity, which constitutes one of the risk factors for cardiovascular diseases.

The impact of hydroxychloroquine-azithromycin combination on Tpeak-to-end and Tpeak-to-end/QT ratio during a short treatment course

BACKGROUND

Since there was no proven treatment of coronavirus disease 2019 (COVID-19), hydroxychloroquine-azithromycin (HCQ-AZM) combination is being used in different countries as a treatment option. Many controversies exist related to the safety and effectiveness of this combination, and questions about how HCQ-AZM combination affects the ventricular repolarization are still unknown.

OBJECTIVE

The aim of the study was to show whether the hydroxychloroquine-azithromycin (HCQ-AZM) combination prolonged Tpeak-to-end (TpTe) duration and TpTe/QT interval ratio or not.

METHODS

One hundred and twenty-six consequent COVID-19(+) patients meeting the study criteria were enrolled in this study. Baseline ECGs were obtained immediately after hospitalization and before commencing the HCQ-AZM combination. On-treatment ECG was obtained 24-48 hr after the loading dose of HCQ/AZM. ECG parameters including PR interval, QRS duration, QT interval, QTc interval, TpTe duration, and TpTe/QT interval ratio were assessed. Demographic and laboratory findings were collected from an electronic recording system.

RESULTS

ECGs of 126 COVID-19(+) patients who received HCQ-AZM combination were assessed. Mean baseline QTc (by Fridericia formula), TpTe, and TpTe/QT ratio were 420.0 ± 26.5 ms, 82.43 ± 9.77 ms, and 0.22 ± 0.02, respectively. On-treatment QTc, TpTe and TpTe/QT ratio were 425.7 ± 27.18 ms, 85.17 ± 11.17 ms, and 0.22 ± 0.03, respectively. No statistically significant acute impacts of HCQ-AZM combination on TpTe duration and TpTe/QT interval ratio were observed compared with baseline values. No ventricular tachycardia/fibrillation and the significant conduction delays were seen during in-hospital follow-up.

CONCLUSION

HCQ-AZM combination increased TpTe duration. However, no significant impact on TpTe/QT interval ratio was observed.

T-Wave Indices and Atherosclerosis

Tpeak-Tend interval, the time difference between the peak and the end of the T-wave, reflects the degree of dispersion of repolarization. Its prolongation has been associated with higher risks of developing ventricular arrhythmias and sudden cardiac death in different pro-arrhythmic conditions such as Brugada and long QT syndromes. In this review, we will provide a comprehensive overview on how Tpeak-Tend is altered in different atherosclerotic conditions such as hypertension, stable coronary artery disease, acute coronary obstruction, and coronary slow flow as well as inflammatory diseases affecting the arterial tree. We will explore its relationship with arterial function and dysfunction, ventricular remodeling, and arrhythmic and mortality outcomes. The published literature shows that patients with coronary atherosclerosis, whether in the form of stable coronary artery disease, chronic total occlusion, slow flow, or acute coronary obstruction, have prolonged Tpeak-Tend intervals and Tpeak-Tend/QT ratios. These can be used to predict the occurrence of ventricular arrhythmias and sudden cardiac death. They also correlate with the extent and severity of arterial stenosis and structural remodeling of the ventricles as well as arterial function and dysfunction. Finally, they can be normalized following revascularization and may therefore be used as a surrogate measure of treatment success.