%0 Journal Article %T Influencia de la variabilidad diurna en el tama£¿o del infarto agudo de miocardio %A Arroyo ¨²car %A E. %A Dominguez-Rodriguez %A A. %A Abreu-Gonzalez %A P. %J Medicina Intensiva %D 2012 %I Ediciones Doyma, S.L. %X objective: to evaluate whether the size of acute myocardial infarction (ami) shows circadian variability. design: an observational, prospective study. setting: a 12-bed coronary care unit. patients: consecutive patients diagnosed with st-elevation myocardial infarction (stemi) undergoing primary percutaneous coronary intervention. interventions: the patients were divided into two groups according to the time of onset of ami symptoms (group a: 0-12hours, group b: 12-24 hours). main variables of interest: age, sex, cardiovascular risk factors, coronary anatomy, left ventricular ejection fraction, infarct location, time from onset of symptoms to reperfusion, presence of heart failure upon admission, and peak troponin i value. results: a total of 108 patients with a diagnosis of stemi were included. patients in group a showed a higher troponin i concentration compared to group b (troponin i: 70.85¡À16.38 versus 60.90¡À22.92ng / ml, p=0.003). in the multivariate analysis the onset of ami between 0-12 hours was identified as an independent predictor of infarct size (or: 1.133, 95%ci 1.012-1.267, p=0.01). conclusions: an onset of ami between 0-12 hours results in a significantly larger final size of necrosis compared with any other time of presentation. %K acute myocardial infarction %K circadian rhythm %K infarct size. %U http://scielo.isciii.es/scielo.php?script=sci_abstract&pid=S0210-56912012000100003&lng=en&nrm=iso&tlng=en