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

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.

Keywords: accidental hypothermia; giant r wave; j wave; osborn wave; premature atrial contraction; standard 12-lead electrocardiogram.

Figure 1. A 12-lead ECG obtained at a core body temperature of 28.1°C on admission

Osborn waves, which are present particularly in the inferior and left precordial leads, are augmented by premature atrial contractions, whereas slurs remain slurs and notches remain notches. In addition, giant R waves in leads with J waves, vertical P-wave axis, rightward frontal QRS axis shift, and phasic voltage variation of QRS complexes when compared to those on the follow-up ECG are also shown. Numbers indicate RR intervals (ms). The arrows indicate Osborn waves. ECG: electrocardiogram

Figure 2. An axial computed tomography image of the chest on admission showing right pneumothorax

A right pneumothorax (asterisk) with the build-up of air between the collapsed right lung (arrows) and chest wall is shown. The heart was suspected to develop a leftward shift. LA: left atrium; LV: left ventricle; RA: right atrium; RV: right ventricle

Figure 3. A plain film chest radiograph following chest drain insertion obtained on day 2 of hospitalization

The right lung is re-expanded with no evidence of pneumothorax or overt pulmonary congestion. The cardiac silhouette is normal. The arrows indicate a chest drain appropriately positioned with its tip pointing superiorly within the pleural cavity. The arrowheads indicate a central venous catheter inserted via the right internal jugular vein, with its tip placed in the superior vena cava or at the cavoatrial junction.

Figure 4. A 12-lead ECG obtained on day 6 of hospitalization

The ECG shows the disappearance of prominent J waves, giant R waves, vertical P-wave axis, rightward frontal QRS axis shift, and phasic voltage variation in QRS complexes. RSR pattern in lead III and notched R in the ascending part of the R wave in lead aVF, which are considered fragmented QRS complex, in addition to the early repolarization pattern with notched or slurred J-point elevation ≥0.1 mV in leads I, II, and V6 are shown. ECG: electrocardiogram