Effects of Extreme Humidity and Heat on Ventricular Arrhythmia Risk in Patients With Cardiac Devices

Area of Science:

• Environmental Health
• Cardiology
• Public Health

Background:

• Climate change is increasing extreme heat and humidity events.
• The impact of these conditions on ventricular arrhythmias (VT/VF) in susceptible individuals is not well understood.

Purpose of the Study:

• To investigate the association between warm-season weather conditions and the risk of VT/VF in patients with pacemakers and defibrillators.

Main Methods:

• A case time-series design was used, linking clinical and device data from 5,944 patients in North Carolina (2010-2021) with daily weather data.
• Distributed lag nonlinear models adjusted for temporal trends and individual factors to assess associations between extreme humidity, temperature, and VT/VF.

Main Results:

• Extreme humidity (90% relative humidity) was associated with increased VT/VF risk within 7 days of exposure (aOR 1.23).
• Increased risk was observed in males, individuals aged 67-75, and those with coronary artery disease, heart failure, diabetes, hypertension, or prior myocardial infarction.
• Higher VT/VF risk was also noted in communities with high socioeconomic deprivation, income inequality, and urban areas with less green space. High temperatures showed no association with VT/VF.

Conclusions:

• Extreme humidity elevates VT/VF risk in patients with cardiovascular disease, particularly in vulnerable subgroups and disadvantaged communities.
• Findings underscore the importance of public health policies addressing environmental risks for susceptible populations.