Favorable electrocardiographic changes after substantial weight loss in patients with morbid obesity : Results of a prospective study.

Background: Obese patients have an increased risk of arrhythmias and sudden death, even in the absence of structural heart disease and cardiac dysfunction. This study aimed to determine whether weight loss by bariatric surgery has an effect on arrhythmia-related electrocardiographic (ECG) variables in morbidly obese patients.

Methods: In this prospective study, the data of 48 patients were analyzed. All ECG variables that have the potential to predict ventricular arrhythmia were evaluated before surgery, and were compared with the 1‑month and 6‑month follow-up results.

Results: The mean body mass index was 45.74 ± 5.60 kg/m before surgery. There was a statistically significant decline in body mass index in the first and sixth month after surgery (39.26 ± 5.00 kg/m and 31.71 ± 4.49 kg/m, respectively; p < 0.001). Furthermore, notable reduction was found in terms of heart rate measurements-QTc‑d, JTc, JTc‑d, Tp‑e, TP-e/QT, TP-e/QTc-in the first month and sixth month compared with baseline (p < 0.001 for all comparisons). Several ECG variables, such as heart rate (r = 0.369, p = 0.001), QTc‑d (r = 0.449, p = 0.001), JTc‑d (r = 0.324, p = 0.002), Tp‑e (r = 0.592, p = 0.001), Tp-e/QTc (r = 0.543, p = 0.001), Tp-e/JTc (r = 0.515, p = 0.001), exhibited a positive and significant correlation with weigh loss. Moreover, a negative and weakly significant correlation was found between the index of cardiac electrophysiological balance (r = -0.239, p = 0.004) and body mass index.

Conclusion: Substantial weight loss following laparoscopic sleeve gastrectomy in obese patients is accompanied by a significant improvement in ventricular repolarization. Therefore, this effect may lead to a decrease in the incidence of lethal ventricular arrhythmia and sudden cardiac death.