The relationship of the occurrence of heart attacks with circadian variations and other cardiovascular risk factors

Background and aim: Heart attacks are among the leading causes of disability and death worldwide. Many intrinsic and extrinsic factors, such as circadian variations, can affect the occurrence of heart attacks. The aim of this study was to investigate the relationship of the occurrence of heart attacks with circadian variations and other cardiovascular risk factors Methods: This descriptive-analytical study was conducted in 2009–2010. A convenience sample of 170 male and 122 female patients (292 patients in total) with ischemic heart disease was recruited. Study data were collected by using questionnaires which were completed through interviewing patients or their families and referring to patients' medical records. The Chi-square test was conducted by using the SPSS software (v. 14) for analyzing the study data. Findings: There was no significant relationship between circadian variations and the occurrence of heart attacks. Moreover, the relationship of the occurrence of heart attacks with demographic characteristics and cardiovascular risk factors was not statistically significant. However, the type of ischemic heart disease was significantly correlated with variables such as employment, gender, and addiction to cigarette (P = 0.0001). Male and female patients differed significantly from each other regarding the time of experiencing a heart attack (P value < 0.05). Conclusion: Circadian variations do not affect the occurrence of heart attacks. Physical and psychological stress can exert more significant effect than circadian variations on the occurrence of heart attacks.