Abstract 3875: Circadian Variation in Sudden Cardiac Death: Data from the National Hospital Ambulatory Medical Care Survey
Objective: To determine the circadian variation in the occurrence of sudden cardiac death.
Background: There is controversy regarding circadian variation in the occurrence of sudden cardiac death. Most studies are limited to selected patient populations and settings.
Methods: Patients with sudden cardiac death were classified by time of occurrence into four categories using demographic and clinical data from the National Hospital Ambulatory Medical Care Survey. Time at initial evaluation was divided into 0000 to 0600 hours, 0600 to 1200 hours, 1200 to 1800 hours, and 1800 to 2400 hours. The relationship between time strata and sudden cardiac death was analyzed in subgroups defined by etiology, age, gender, and race/ethnicity.
Results: A total of 155,942 patients presenting to the emergency room met the criteria for sudden cardiac death. The distribution of patients according to time evaluated is presented in the graph suggesting a clustering of events between 1200 and 1800 hours. The subgroup analyses did not demonstrate any significant differences between various strata.
Conclusions: In a nationally representative large dataset, circadian variation was observed in the occurrence of sudden cardiac death. This finding may have implications for understanding the predisposing states for sudden cardiac death.