Author + information
- Received December 23, 2018
- Revision received April 17, 2019
- Accepted May 6, 2019
- Published online July 31, 2019.
- Abhishek Maan, MD, ScMa,
- Lou Sherfesee, PhDb,
- Daniel Lexcen, PhDb,
- E. Kevin Heist, MD, PhDa and
- Alan Cheng, MDb,∗ ()
- aCardiac Arrhythmia Service, Massachusetts General Hospital, Boston, Massachusetts
- bMedtronic, Mounds View, Minnesota
- ↵∗Address for correspondence:
Dr. Alan Cheng, Medtronic, 8200 Coral Sea Street, MVS-2, Mounds View, Minnesota 55112.
Objectives The aim of this study was to assess the variations in ventricular arrhythmia (VA) occurrence according to seasons, months of the year, days of the week, and the time of day in a large implantable cardioverter-defibrillator patient population.
Background Limited data exist on how VA occurrence varies as a function of time.
Methods Data from 6 prospective studies were pooled to assess VA frequency over time. All adjudicated episodes of VAs ≤500 ms were included. VA distribution as a function of hour, day, month, and season were assessed through the construction of 4 negative binomial models. The models included a random patient effect and offset for days spent in each time period.
Results Among 3,969 patients, 7,126.8 cumulative device-years with an average follow-up duration of 1.8 ± 1.4 y/patient were analyzed. VA occurrence was higher in the spring than the summer (0.86% vs. 0.70%; p = 0.009) but not significantly different from the fall (0.74%; p = 0.069) or winter (0.84%; p = 0.732). The estimated probability of occurrence of at least 1 VA episode in each 1-h block during the hours of 8 am to 10 pm over 365 days (0.10% to 0.12%) was higher (estimated 35% to 63% higher) than the referent period of midnight to 1 am (0.07%). No significant variations in VA occurrence were observed according to weekday and individual months of the year.
Conclusions Significantly higher VA occurrence in the spring and during the hours of 8 am to 10 pm were observed. Additional studies are needed to further understand the reasons for these observations, which may involve variations in temperature or differences in catecholamine triggers.
Dr. Maan has received research grants from Medtronic, Biotronik, and Biosense Webster. Dr. Sherfesee is an employee of Medtronic. Dr. Lexcen is an employee of Medtronic. Dr. Heist has received honoraria from Biotronik, Boston Scientific, Medtronic, Abbott, and Johnson and Johnson (all modest in amount); has received research grants from Boston Scientific and Abbott (all modest in amount); and has received consulting fees from Pfizer (modest in amount). Dr. Cheng is an employee of Medtronic.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received December 23, 2018.
- Revision received April 17, 2019.
- Accepted May 6, 2019.
- 2019 American College of Cardiology Foundation