# Marked QTc Interval Prolongation Associated With Dronedarone in Paroxysmal Atrial Fibrillation and No Structural Disease

## TL;DR

A 44-year-old man with no heart disease experienced significant QTc prolongation while taking dronedarone for atrial fibrillation, showing the need for ECG monitoring.

## Contribution

Highlights previously underappreciated QTc prolongation risk of dronedarone in low-risk atrial fibrillation patients.

## Key findings

- Dronedarone caused marked QTc prolongation in a patient with no structural heart disease.
- QTc prolongation occurred without symptoms, emphasizing the need for ECG monitoring.
- Case suggests dronedarone may carry higher proarrhythmic risk than previously thought.

## Abstract

Dronedarone, a multichannel antiarrhythmic drug, was developed as a safer alternative to amiodarone for atrial fibrillation. Although initially considered to have a lower proarrhythmic risk, post-marketing data and clinical experience suggest otherwise. We describe the case of a 44-year-old male with paroxysmal atrial fibrillation and no structural heart disease who developed marked QTc prolongation while receiving dronedarone, despite being asymptomatic. This case highlights the potential for clinically silent but significant QTc prolongation during dronedarone therapy, underscoring the importance of careful ECG monitoring, even in low-risk patients.