Circadian variation of death from congestive heart failure after prior myocardial infarction in patients >60 years of age

In the present prospective study, there was a circadian pattern in the number of deaths per hour in patients with congestive heart failure after prior myocardial infarction. The primary peak occurred between 6 a.m. and 12 p.m., with 202 of 517 deaths (39%) occurring in that 6-hour period.