Introduction: Abnormal ventricular repolarization has been proposed as a marker of arrhythmogenesis, and cardiovascular morbidity and mortality. However, little is known about the influence of the interval between the peak and the end of the T wave (Tp-Te) on the inducibility of sustained ventricular arrhythmias (VA) in patients with Chagas disease (CD).
Methods: Using a case-control design, chagasics undergoing electrophysiological study (EPS) in the last three years were matched by age and sex. Cases represented those with positive EPS and controls those with no inducible VA. Tp-Te>100 ms was considered abnormal. Logistic regression analysis was performed to assess the association between Tp-Te and a positive EPS, after adjusting for confounders.
Results: A total of 105 patients (mean age 56 years, 52.4% male) were included: 41 (39%) had a positive EPS; 85.4% with inducible VA (n=35) had non-sustained ventricular tachycardia on the Holter monitoring, compared to 62.5% with negative EPS (n=40, p<0.001). While ventricular aneurysm (adjusted OR=5.3, 95% CI: 1.11-24.96, p=0.03) and coronary artery disease (adjusted OR=8.8, 95% CI: 1.45-53.15, p=0.01) were associated with an increased risk of malignant arrhythmias, a greater ejection fraction (adjusted OR=0.96, 95% CI: 0.93-0.99, p<0.01) was associated with a lower risk of VA. Prolonged Tp-Te trended to be associated with an increased risk of induced VA (p=0.07).
Conclusions: Ventricular aneurysm, coronary artery disease, and ejection fraction are associated with inducible VA. Prolonged TP-Te may have a modest role in the identification of patients with CD who are at high risk for VA. Further studies are warranted to validate our results and to correlate them with clinical outcomes.