# Evaluation of electrocardiographic alterations before and after bariatric surgery

**Authors:** Shokoufeh Hajsadeghi, Aida Iranpour, Faranak Olamaeian, Ali Tayebi, Mahdis Gheitasi

PMC · DOI: 10.21542/gcsp.2025.22 · 2025-05-15

## TL;DR

This study found that bariatric surgery in severely obese patients led to significant improvements in heart-related measurements, including a reduced corrected QT interval.

## Contribution

The study provides empirical evidence of electrocardiographic improvements following bariatric surgery in patients with severe obesity.

## Key findings

- Bariatric surgery significantly reduced the corrected QT interval in severely obese patients.
- Heart rate, blood pressure, and blood sugar levels also decreased significantly after surgery.
- Body mass index and waist circumference were notably reduced six months post-surgery.

## Abstract

Background: Obesity is a key risk factor for cardiac arrhythmia and sudden cardiac death. Additionally, morbid obesity is associated with an acquired elongation of the corrected QT interval, which could potentially lead to dangerous arrhythmias. In this study, we compare electrocardiography changes in patients with body mass index ≥40 before and after bariatric surgery.

Methods: We enrolled 55 patients with severe obesity in this study. All patients underwent bariatric surgery; electrocardiography along with anthropometric data and laboratory tests before and at least six months after bariatric surgery were performed.

Results: In total, 55 patients completed the study protocol (44 women and 11 men) and the mean age was 37.0 ± 10.5 years. Mean body mass index decreased from 46.7 ± 6.1 to 32.5 ± 5.1 (P < 0.0001) and the average variables of waist circumference, systolic and diastolic blood pressure, fasting blood sugar and glycated hemoglobin before and at least six months after bariatric surgery were significantly decreased (P < 0.0001). The postoperative assessment revealed a considerable decrease in the heart rate (P < 0.0001) and the corrected QT interval (P < 0.003).

Conclusion: This study showed that in a select group of patients with severe obesity, the corrected QT interval was reduced at least 6 months following the procedure. Also, as we expected, we observed decrease in systolic and diastolic pressure, heart rate, fasting blood sugar, glycated hemoglobin, the body indices including body mass index and waist circumference notably.

## Linked entities

- **Diseases:** obesity (MONDO:0011122), sudden cardiac death (MONDO:0007264)

## Full-text entities

- **Diseases:** Obesity (MESH:D009765), sudden cardiac death (MESH:D016757), arrhythmias (MESH:D001145), morbid obesity (MESH:D009767)
- **Chemicals:** blood sugar (MESH:D001786)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC13025551/full.md

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Source: https://tomesphere.com/paper/PMC13025551