Mohammad Rouzbahani - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Javad Azimivaghar - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Nader Asgari - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Nafiseh Montazeri - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Nahid Salehi - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Mostafa Bahremand - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Reza Heidari-Moghadam - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Alireza Rai - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Maryam Babakhani - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
Sousan Mahmoudi - Cardiovascular Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran

BACKGROUND: Circadian variation is known as an important factor in acute myocardial infarction (AMI). Moreover, the circadian pattern may help in disease prevention and better medication prescription. Therefore, the aim of our study was to investigate the circadian pattern of symptom onset in patients with ST-segment elevation myocardial infarction (STEMI).METHODS: This cross-sectional study was conducted on ۷۷۷ patients admitted to the Imam Ali Cardiovascular Center, Kermanshah, Iran, with a diagnosis of STEMI from March ۲۰۱۸ to February ۲۰۱۹. Data were collected using a checklist developed based on the study's objectives. Differences between subgroups were assessed using one-way analysis of variance (ANOVA) with post-hoc testing and chi-square test (or Fisher’s exact test).RESULTS: Out of the ۷۷۷ patients, ۶۱۶ (۷۹.۳%) were men. The mean and standard deviation (SD) of age of the patients was ۶۰.۹۳ ± ۱۲.۸۶ years. ۳۸۰ patients (۴۸.۹%) were current smoker, ۴۰.۳% were hypertensive, ۲۱.۱% had hypercholesterolemia, ۱۸.۳% had diabetes mellitus (DM), ۲۵.۲% had history of angina, and about ۱۵.۰% had history of myocardial infarction (MI). The occurrence of STEMI was most common during hours between ۰۶:۰۱-۱۲:۰۰ (۲۷.۷%), followed by ۱۲:۰۱-۱۸:۰۰ (۲۷.۳%), ۰۰:۰۰-۰۶:۰۰ (۲۴.۳%), and ۱۸:۰۱-۲۴:۰۰ (۲۰.۷%), respectively. Gender was significantly associated with circadian pattern of STEMI. Women showed a double peak of symptom onset in ۰۶:۰۱-۱۲:۰۰ and ۱۲:۰۱-۱۸:۰۰.CONCLUSION: The present study of Iranian patients displayed circadian pattern of STEMI with ۲ peaks in the morning and afternoon, and the both peaks were dominated by women.

Circadian Rhythm, Myocardial Infarction, Iran