# Ventricular fibrillation during football training as a consequence of kratom and caffeine use in an adolescent: case report

## TL;DR

An 18-year-old experienced ventricular fibrillation during football training, possibly due to kratom and caffeine use, highlighting the risks of these substances.

## Contribution

This case report is the first of its kind to suggest a link between kratom, caffeine, and exercise-induced ventricular fibrillation in adolescents.

## Key findings

- Ventricular fibrillation occurred in an adolescent during exercise after kratom and caffeine use.
- No pathogenic gene variant was found, but a variant of unknown significance was identified in MYOM1.
- The patient was implanted with an ICD and has had no recurrence of arrhythmia.

## Abstract

There is an increase in the sale of legal drugs in our country. One of these substances is kratom. Kratom (Mitragyna speciosa) is a partial agonist of the opioid kappa, mu, and delta receptors. It acts as a stimulant at low concentrations, making users feel more energetic and euphoric. It has sedative and antinociceptive effects at higher doses.

An 18-year-old man collapsed during football training and required cardiopulmonary resuscitation; the initial rhythm was ventricular fibrillation managed by defibrillation. Laboratory parameters were unremarkable. Blood samples sent for toxicological evaluation were positive for kratom and caffeine. Echocardiographic examination, coronary computed tomography angiography, and cardiac magnetic resonance imaging did not prove the cause. Genetic testing did not find a pathogenic gene variant associated with familial ventricular fibrillation, but a variant of unknown significance was found in MYOM1. Given this situation, we implanted an implantable cardioverter-defibrillator (ICD) from the secondary prevention of sudden cardiac death (SCD) according to the guidelines of the European Society of Cardiology (ESC). No recurrence of ventricular arrhythmia has been reported by ambulatory ICD memory checks on our patient.

In some country, kratom is freely available and sold as a plant, not a drug. Only incident cases of ventricular fibrillation after kratom use are described in the literature. There is insufficient scientific evidence linking kratom to ventricular fibrillation. This is an absolutely crucial case report of this type, which has not yet been published in similar circumstances in the world. Therefore, the development of ventricular fibrillation was assumed to be due to a combination of kratom, caffeine, and exercise. The safety profile and effects of kratom should be the subject of future research. We would like to stress the importance of reporting further case series for more scientific evidence and thus increasing the pressure for stricter availability and regulation of kratom in some countries, especially where it is over-the-counter.