# Accidental Hypothermia-Induced J Wave Coupled With Giant R Wave Augmented by Premature Atrial Contraction: A Case Report

## TL;DR

This case report describes a rare ECG pattern in a hypothermic patient, suggesting J waves are caused by conduction delays rather than transient currents.

## Contribution

The report presents a novel ECG finding of J waves coupled with giant R waves during hypothermia, supporting conduction delay as the mechanism.

## Key findings

- Hypothermia-induced J waves were observed alongside giant R waves, a previously unreported combination.
- Short RR intervals from premature atrial contractions augmented the giant R wave phenomenon.
- Findings support that J waves arise from conduction delay rather than transient outward currents.

## Abstract

The 12-lead electrocardiographic findings in hypothermia include the presence of J waves; prolongation of the PR, QRS, and QT intervals; and atrial and ventricular dysrhythmias. Among these findings, the J wave, known as the Osborn wave, is considered pathognomonic. In 1953, the J wave was reported as a specific response to hypothermia in dogs, representing the current at the site of injury instead of a widening of the QRS complex that occurs caused by a conduction delay. The J wave is often accompanied by ventricular fibrillation. For the past 28 years, it was assumed that the hypothermia-induced J wave was mediated by the transient outward current. However, it was recently been reported that the J waves in some patients with hypothermia can be considered delayed conduction-related waveforms. Here, we present a case of hypothermia-induced J waves together with giant R waves, which have not been previously reported during hypothermia, augmented by short RR intervals arising from premature atrial contractions. Our observations indicate that the underlying mechanism for the genesis of J waves is indeed conduction delay and not transient outward currents.