Extreme Heat and Arrhythmia in Patients With Implanted Devices.

Area of Science:

• Environmental Health
• Cardiology
• Climate Change Impacts

Background:

• Global incidence of arrhythmia, particularly atrial fibrillation (AF), is increasing.
• While known risk factors contribute, the impact of emerging risks like extreme heat remains underexplored.

Purpose of the Study:

• To investigate the association between ambient temperature and cardiac arrhythmia events.
• To determine if extreme heat is a risk factor for atrial tachycardia/fibrillation (AT/AF) and ventricular tachycardia/fibrillation (VT/VF).

Main Methods:

• Utilized a US-based registry of implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator devices (2016-2023).
• Employed a case-crossover design matching arrhythmia event hours with control hours for individual patients.
• Analyzed nonlinear dose-response relationships between temperature and arrhythmia using conditional logistic models across all US climate zones.

Main Results:

• A significant dose-response relationship was found between high outdoor temperatures and AT/AF events.
• At 39°C, 40°C, and 41°C, the odds ratios for AT/AF events were 2.41, 2.60, and 2.81, respectively, compared to 19°C.
• No significant association was observed between temperature and ventricular tachycardia/ventricular fibrillation events.

Conclusions:

• Extreme hot outdoor temperatures are significantly associated with increased odds of atrial fibrillation episodes.
• This finding highlights a potential public health risk linked to climate change and rising global temperatures.