# Daily Energy Drink Intake and Arrhythmia Resistant to Direct Current Cardioversion

## TL;DR

A young woman with a history of heart rhythm issues had treatment-resistant arrhythmia, possibly linked to her daily energy drink consumption.

## Contribution

This case highlights the potential role of energy drink consumption in causing resistance to electrical cardioversion in supraventricular tachycardia.

## Key findings

- The patient's excessive energy drink intake may have contributed to treatment-resistant arrhythmia.
- Higher-energy shocks were required to restore normal heart rhythm despite appropriate initial attempts.
- The case suggests a possible link between stimulant consumption and altered myocardial response to cardioversion.

## Abstract

Supraventricular tachycardia (SVT) is a common arrhythmia, often responsive to pharmacologic intervention or electrical cardioversion. Resistance to direct current cardioversion (DCCV) is uncommon and can be clinically challenging. Lifestyle factors, including dietary stimulant intake, may influence arrhythmia dynamics and treatment responsiveness. We present a case of a 26-year-old female known to have SVT, who presented with six hours of palpitations, with a past medical history of successful cryoablation performed in 2021 for atrial tachycardia originating from tissue near the atrioventricular bundle. Her maintenance therapy included bisoprolol 2.5 mg. Notably, the patient reported regular and excessive consumption of energy drinks, averaging multiple servings daily. The pharmacological intervention failed to achieve rhythm control, necessitating DCCV. Despite appropriate sedation and energy dosing, initial cardioversion attempts were unsuccessful. Subsequent higher-energy shocks ultimately restored sinus rhythm. This case underscores an unusual presentation of cardioversion-resistant SVT in a young adult with prior ablation. The patient’s habitual intake of energy drinks raises concern for potential pro-arrhythmic and electrophysiologic alterations induced by high caffeine and other stimulant content. While caffeine’s arrhythmogenic potential is recognized, its role in altering myocardial excitability and threshold for cardioversion is not well established. This case adds to the limited literature suggesting that excessive stimulant use may contribute to treatment-resistant arrhythmic episodes. Clinicians should be aware of dietary and lifestyle factors, such as energy drink consumption, which may influence the efficacy of electrical cardioversion. Further research is warranted to elucidate the mechanisms by which stimulants impact cardioversion outcomes in patients with SVT.