---

Background and Aim: Many studies have reported a circadian variation with a peak in the rate of acute myocardial infarction in mornings. The purpose of this study is further analysis of circadian patterns with which symptoms of AMI occur in a different population with different characteristics that influence their physiologic status. Materials and Methods: A descriptive study was done on 246 patients with the diagnosis of AMI. Patients were questioned about their activity during 30 minutes prior to onset of pain, exposure to stress in the past 24 hours, history of diseases and cardiac medications. The frequency of symptom related to attacks within four periods of 6 hours (6 Am to 12 MD, 12 MD to 6 PM, 6PM to 12 MN, and 12 MN to 6 Am) in all samples and sub groups were gathered.The data were analyzed using Chi-Square test and analysis of variance test. Results: The data revealed no significant circadian variation, regarding to attacks of acute myocardial infarction. However, statistically significant relation between the onset time and physical activity (P<0.0001), and stress exposure before pain (P<0.05) was observed, also no significant relationship between onset time and other variables was noticed. Conclusion: The findings were in contrast to previous reports, and no circadian rhythm was observed in occurrence of AMI so further studies are required to clarify the presence of circadian rhythm in onset of AMI and interaction between endogenous and exogenous rhythms and ischemic events in different population with different conditions.

---

Background and Aim: Statins provide effective secondary prevention in cardiovascular disease. However, it remains controversial that how soon statin should be started after an Acute Coronary Syndrome (ACS). We hypothesize that statins should be initiated without delay. Materials and Methods: In this interventional study we had two groups of patients in cardiovascular research center of Mashhad University of medical sciences in 2007 with acute ST elevation Myocardial Infarction (MI), which in one group (150 cases) statin was started early after Myocardial Infarction (MI) and in the second group (150 cases) not receiving statin or it started after at least 48 hours. The data were analyzed with student t-test and x2 test. Results: The first time Statin receivers had lower (all cases) 7 day mortality and better outcomes. Our study showed that major cardiac events are also lower in the study group. Conclusion: These data suggest that very early Statin therapy is associated with reduced mortality rate in patients with myocardial infarction.