Weather and triggering of ventricular arrhythmias in patients with implantable cardioverter-defibrillators

Abstract

Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR) = 1.16, 95% confidence interval (CI) 1.05–1.27 for a 1 °C decrease in the 24-h average) and lower absolute humidity (OR = 1.06, 95% CI 1.03–1.08 for a 0.5 g/m3 decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients.

Fine-scale spatial and temporal variation in temperature and arrhythmia episodes in the VA Normative Aging Study

“…In the same cohort the authors found a nonlinear association between outdoor temperature and ventricular arrhythmias, with lower temperature and drier air were associated with increased risk of ventricular arrhythmia onset (Nguyen et al, 2013). Similarly, in another study of implanted cardiac defibrillators and daily outdoor temperatures McGuinn et al found a negative association between outdoor temperature and ventricular arrhythmias (McGuinn et al, 2013).…”

“…Increased mortality has been linked not only to heat wave episodes (Kaiser et al, 2007; Le Tertre et al, 2006; Ostro et al, 2009), but also to exposure to colder weather conditions (Analitis et al, 2008; Lee et al, 2014). These studies focused on hospital admissions or mortality, while fewer studies have investigated patient’s specific onset of arrhythmia (Nguyen et al, 2013; Nguyen et al, 2015; McGuinn et al, 2013). Some studies showed that chronic disease including cardiovascular disease, diabetes mellitus, mental illness, but also sociodemographic characteristics, and social isolation may heighten susceptibility to temperature-related mortality (Basu, 2009; O’Neill et al, 2003; Zanobetti et al, 2013), and that even without known chronic medical conditions, aging may increase susceptibility to the cardiovascular effects of temperature extremes and changes in temperature.…”

Drier Air, Lower Temperatures, and Triggering of Paroxysmal Atrial Fibrillation

“…Further complicating the interpretation of these results is the fact that outdoor and indoor temperatures in Boston correlate weakly in the colder months because of universal home heating. 28 Nguyen et al 29 found a nonlinear association between outdoor temperature and ventricular arrhythmias in a cohort of patients implanted with cardioverter-defibrillators living in Boston, which they attributed to the poor correlation between outdoor and indoor temperatures during the winter months. It is possible that the current study did not have sufficient power to detect a nonlinear association for temperature.…”

Hospitalizations from Hypertensive Diseases, Diabetes, and Arrhythmia in Relation to Low and High Temperatures: Population-Based Study

“…Comprising all residents of New York City, US, this study reported that summer-time high temperatures were associated with reduced risk of hypertension-related hospital admissions, but it did not evaluate any possible effect from cold temperatures. The impact of temperatures on diabetes 15 16 17 and arrhythmia 18 19 , two conditions that often co-exist 20 21 22 23 24 with hypertension and share similar risk factors 25 , have been assessed in a handful of studies. A positive relationship between diabetes-related hospital admissions and apparent temperature (a composite index of temperature and humidity) was found in California, US 15 .…”

“…The relationship between diabetes hospitalizations and heat waves was also investigated in two other studies, with a positive association reported in one study 16 but null association in another 17 . More recently, two panel studies of patients implanted with cardioverter-defibrillator devices reported that cold temperatures may trigger arrhythmia 18 19 .…”