Circadian Variation Of Acute ST Segment Elevation Myocardial Infarction By Anatomic Location

Objective:The aim of this study was to evaluate the relationship between site of infarction(anterior vs. inferior) and circadian variation in patients with acute ST segment elevation myocardial infarction(STEMI).Methods:140 cases of patients with acute STEMI in the cardic intervention center of the Second Affiliated Hospital of Nanchang University were enrolled between October 2014 to October 2015.Including 65 cases of anterior wall myocardial infarction and 75 cases of inferior wall myocardial infarction.According to patients, self-reports,the time in which chest pain had started was considered as the beginning of AMI.Collected general information of patients(including age,personal history,past history),and collected the related inspection index(including lipids,cardiac troponin,B-type brain natriuretic peptide,left ventricular ejection fraction).00:01~24:00 divide evenly into four time periods(00:01~06:00, 06:01~12:00, 12:01~18:00,18:01~24:00).Each time period of myocardial infarction incidence,morbidity spot and the related inspection results were univariate analysised by chi square analysis and student's t test.The risk factors for myocardial infarction in different parts were screened by multivariate logistic regression analysis.Results:The age of patients we recruited was 32~85.The mean age of the study population was 63.82±11.38;Of 140 patients,there were 102 male and 38 female patients,accounted for 72.85% and 27.15%,respectively.The symptoms onset was as follows: 00:01 to 06:00,45(32.14%);06:01 to 12:00,34(24.28%);12:01 to 18:00,37(26.43%);18:01 to 24:00,24(17.14%).The distribution of different parts in different time periods has a significant difference(?2=20.497,P<0.001),The onset of acute anterior MI mainly occurred in 06:01 to 12:00 and 12:01 to 18:00,accounted for30.76% and 40.00%,respectively.Multivariate logistic regression analysis showed that the risk of myocardial infarction occurred in the anterior wall in 06:01 to 12:00 and12:01 to 18:00 was higher than those of 06:01 to 12:00(OR=8.492,95%CI:2.476~29.120;P=0.001;OR=15.440,95%CI:4.527~52.663;P<0.001,respectively).The onset of acute inferior MI mainly occurred in 00:01~06:00 and 18:01~24:00,accounted for 44.00% and 22.67%,respectively.Multivariate logistic regression analysis showed that the risk of myocardial infarction occurred in the inferior wall in0:01~6:00 and 18:01~24:00 was higher than those of 06:01~12:00(OR=8.492,95%CI:2.476~29.120;P=0.001;OR=4.356,95%CI:1.258~15.082;P<0.001,respectively).No significant differences were found between circadian variation and site of acute STEMI regarding clinical characteristics,i.e.smoking,drinking,hypertension,diabetes and other factors of acute STEMI happened, among the 6-h period groups.Conclusion:Different circadian periodicity in the time of onset of STEMI was found regarding infarction site in our research. This may be related to genetic and?or demographic characteristics of the general population.