How does hypothermia affect an EKG?

Hypothermia has a significant impact on the electrocardiogram (EKG), particularly by prolonging the QT interval. When the body temperature drops, it affects the electrical conduction system of the heart, which can lead to an alteration in the repolarization phase of the cardiac cycle. This manifests as a prolonged QT interval on the EKG.

A prolonged QT interval can increase the risk of life-threatening arrhythmias, such as Torsades de Pointes, indicating that hypothermia's effects on the heart are not merely superficial. The decreased metabolic rate and slowed cellular activity associated with lower body temperatures can further disrupt normal heart rhythms. Therefore, understanding that hypothermia can lead to significant and measurable changes in the heart's electrical activity is crucial for monitoring and managing patients in a hypothermic state.