# Silent and Cold: A Case of Bradycardia Associated With Isolated Hypothermia

## TL;DR

This case study shows how treating hypothermia resolved a patient's abnormally slow heart rate, highlighting the link between the two conditions.

## Contribution

The paper presents a rare case where isolated hypothermia was the sole cause of bradycardia.

## Key findings

- The patient's bradycardia resolved after treating hypothermia.
- Common cardiac causes were ruled out, confirming hypothermia as the underlying issue.

## Abstract

Sinus bradycardia is defined as a heart rate of less than 60 beats per minute and can occur as an adaptive response but can also be pathologic. Sinus bradycardia can be a normal finding in children, individuals who exercise often, and as a physiologic response during sleep. Pathologic causes of sinus bradycardia include sinus node dysfunction, medications, acute myocardial infarction, heart failure, obstructive sleep apnea, exaggerated vagal activity, increased intracranial hypertension, infection, hypothyroidism, hypothermia, anorexia nervosa, and prolonged hypoxia. When pathologic, addressing the underlying cause will lead to an improvement in heart rate. Here, we present a case of sinus bradycardia in a 61-year-old female with hypothermia. Evaluation for common causes of bradycardia including cardiac evaluation was unremarkable. Treatment of hypothermia led to the resolution of bradycardia. The importance of the case is to help clinicians recognize hypothermia as a cause of bradycardia.