Abstract: ［Abstract］ Objective〖HTSS〗To evaluate the relationship between the circadian rhythm and the slow/noreflow phenomenon after percutaneous coronary intervention(PCI) in patients with acute STsegment elevation myocardial infarction(STEMI).
〖HTH〗〖WTHZ〗Methods〖HTSS〗Three hundred and twelve STEMI patients treated with emergency PCI were divided into normal flow group (286 cases) and slow flow group(26 cases) or no reflow group according to the results of PCI. The basic clinical data of the two groups were compared. The correlation factors between slow blood flow and no reflow after emergency PCI were screened and further multivariate Logistic regression analysis was performed.
〖HTH〗〖WTHZ〗Results〖HTSS〗〖JP2〗Multivariate Logistic regression analysis showed that body mass index ≥〖JP〗28 and reperfusion time ≥6 h were risk factors for slow flow/no reflow after emergency PCI for STEMI patients(P＜0.05).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗Circadian  rhythm has no effect on the occurrence of slow blood flow or no reflow after emergency coronary intervention in patients with acute STEMI.

Key words: myocardial infarction, percutaneous cornonary intervention, noreflow phenomenon