# QT Prolongation and Torsade De Pointes After Catheter Ablation for Persistent Atrial Fibrillation in a Patient With Tachycardia-Induced Cardiomyopathy: A Case Report

## TL;DR

A patient with tachycardia-induced cardiomyopathy developed QT prolongation and Torsade de Pointes after catheter ablation for atrial fibrillation, highlighting the need for careful risk management.

## Contribution

This case report highlights the rare occurrence of QT prolongation and Torsade de Pointes in patients with tachycardia-induced cardiomyopathy undergoing catheter ablation.

## Key findings

- QT prolongation and Torsade de Pointes occurred in a patient with tachycardia-induced cardiomyopathy after catheter ablation.
- No evidence of myocardial edema or coronary artery abnormalities was found.
- QT prolongation and left ventricular dysfunction improved without treatment.

## Abstract

Atrial fibrillation (AF) is the most common cause of tachycardia-induced cardiomyopathy (TIC). A 75-year-old woman was referred to our hospital for catheter ablation for persistent AF. On admission, transthoracic echocardiography (TTE) revealed diffuse left ventricular (LV) hypokinesis, which was suspected to be due to TIC. Catheter ablation was performed on the fifth day of hospitalization, and Torsade de Pointes (TdP) appeared on the sixth day. The serum concentration of bepridil and potassium was below the reference level. An electrocardiogram revealed marked QT prolongation, giant-negative T waves, and T-wave alternans on the seventh day of hospitalization. Cardiac magnetic resonance imaging with no contrast indicated diffuse mild LV hypokinesis, mild prolonged native T1, and no evidence of myocardial edema at T2. Coronary angiography revealed normal coronary arteries, and the ergonovine stress test results were negative. The results for five long QT syndrome susceptibility genes, including the three major genes, were negative. Subsequently, QT prolongation, giant-negative T waves, and LV dysfunction improved without treatment. This case report highlights the importance of risk management for AF patients with TIC scheduled for catheter ablation and carefully evaluating the risks of QT prolongation. Moreover, patients with TIC can experience marked QT prolongation and TdP during the perioperative period of catheter ablation. Therefore, caution should be required.