Increased morning incidence of myocardial infarction in the ISAM Study: absence with prior beta-adrenergic blockade. ISAM Study Group.

Abstract

(Circulation 1989;80:853-858) T he incidence of myocardial infarction has been reported to exhibit a circadian variation.1 This finding was revealed in the data base evaluation of a major myocardial infarction study, and its significance is not yet clear. However, the potential importance of the observation is underlined by the emerging knowledge of a circadian variation in the incidence of other cardiovascular diseases, such as sudden cardiac death, symptomatic and asymptomatic myocardial ischemia, and stroke, all of which have been shown to occur more frequently during the morning than at other times of day. [2][3][4][5][6] In the case of myocardial infarction and sudden cardiac death, a minor secondary peak period in the

Circadian Variation of the Onset of Acute Myocardial Infarction in the Osaka Area, 1998-1999

“…The morning peak of the onset of AMI has been consistently observed in previous studies [1][2][3][4][5][6][7][8][9][10] and is probably associated with the normal biologic rhythm. Our data also indicate that these intrinsic circadian rhythms are important triggering mechanisms of AMI in elderly females.…”

“…The study group comprised 1,609 consecutive patients with AMI who were admitted to 25 collaborating hospitals within 1 week of onset between April 1998 and January 2000. The diagnosis of definite AMI required 2 of the following 3 criteria: (1) a clinical history of central chest pressure, pain, or tightness lasting for 30 min or more, (2) ST-segment elevation greater than 0.1 mV in at least one standard or 2 precordial leads, and (3) a rise in serum creatine kinase concentration to greater than twice the normal laboratory value. Standard clinical variables, including the timing of the onset of AMI, therapeutic procedures and clinical events, were assessed during the patient's stay in hospital.…”

Circadian Patterns of ST Elevation Myocardial Infarction in the New Millennium

“…In addition to changes in lifestyle and medical intervention, significant progress has also been made in the past several years in recognizing differences in symptoms of ischemic heart disease in women. 26 Accordingly, the number of female subjects noted in studies over time has increased from 18.4% in a 1989 study by Willich et al 7 to 21% in 1997 by Sayer et al, 12 and 31% in the present study. Our findings are consistent with those that have appeared in the literature over time, 11,13,15,17 and suggest that despite major changes in lifestyle and significant improvements in medical care over the past nearly four decades, the effects of circadian rhythm on AMI occurrence have remained constant.…”

Impact of the human circadian system, exercise, and their interaction on cardiovascular function

“…As we hypothesized, the endogenous circadian trough in most of the cardiovascular risk biomarkers, as well as the circadian peak in "protective" vagal markers, occurred during the biological night (≈midnight-8:00 AM; ≈300°-50°) for most variables (except for cortisol: 10:30 PM; 270°; Table 1), possibly underlying the nighttime trough in adverse cardiovascular events in epidemiological studies (3)(4)(5)(6)(7)(8)(9)(10).…”

“…cardiovascular disease C ardiovascular disease is the leading cause of mortality in both men and women in developed countries (1,2). Epidemiological studies show a clear day/night pattern in risk for myocardial infarction (3)(4)(5)(6), stroke (7), angina (5), ventricular arrhythmias (8), and sudden cardiac death (9) with primary peaks in the morning (≈6:00 AM-noon), secondary peaks in the evening (≈6:00-10:00 PM), and lowest vulnerability during the night (≈midnight-6:00 AM) (reviewed in ref. 10).…”