Circadian variation of sudden cardiac death reflects age-related variability in ventricular fibrillation.

Abstract

The circadian pattern of sudden cardiac death reflects primarily a circadian variation in onset of ventricular fibrillation. The different circadian patterns of ventricular fibrillation, pulseless bradyarrhythmias, and asystole suggest different pathophysiological mechanisms of causation of death. The age dependence of the pattern of ventricular fibrillation may indicate different underlying external or endogenous triggers.

Examination of Patterns in Intubation by an Emergency Airway Team at a Large Academic Center: Higher Frequency During Daytime Hours

“…It is impossible to determine from these data the explanation for such a drop in frequency overnight, although there is evidence to support circadian variations in the frequency of medical emergencies. 6 An alternative possibility would be diurnal variations in the extent of attention and therapeutic interventions delivered to patients, perhaps as a calculated tradeoff to improve sleep quality and quan- tity. 13,14 This phenomenon has been witnessed when studying calls to medical emergency teams 15 and might imply that intubations that should have been performed overnight are instead delayed until daybreak.…”

“…[6][7][8][9] We therefore hypothesized that the majority of airway emergencies would follow this pattern, with the greatest number of airway consults occurring before the start of a standard work day, particularly during late night and early morning hours. Given the usual reduction in resources during such hours, an increase in emergency airway events would have potential implications for staffing adequacy.…”

Long-Term Follow-up of the Circadian Rhythm of Heart Rate and Heart Rate Variability in Healthy Elderly Patients

“…[11][12][13][14]19 Furthermore, cardiovascular events occur more frequently in elderly people and aging itself is an independent risk factor. 11,12,19 However, how HRV changes with aging in elderly patients and how ANA is involved in the occurrence of cardiovascular events are still unknown.…”

“…Arntz et al also reported that more cardiovascular events in the morning occurred in subjects over 65 years old. 11,12 Accordingly, these age-related changes in the time course, or the fluctuation, of the ANA in the morning might be a characteristic of elderly people and the background to their susceptibility to cardiovascular events in the morning.…”

Warning: The Short Days of Winter May Be Hazardous to Your Health

“…8 Changing electrophysiological conditions accompany the greater frequency of morning sudden death, which may be due to ventricular fibrillation. 9 A morning peak in ventricular tachyarrhythmias can be detected by therapy delivered with implantable cardioverter-defibrillators. 10 Maximal shortening of ventricular effective refractory period occurs in the early morning hours, 11 along with a morning peak in defibrillation threshold and failed first shock frequency.…”