[Reperfusion arrhythmias in acute myocardial infarction do not enhance myocardial injury].
OBJECTIVE
To investigate the clinical implications of reperfusion arrhythmias during primary percutaneous coronary intervention (PCI) for patients with acute myocardial infarction (AMI).


METHODS
Data from 228 AMI patients in whom the infarct-related artery (IRA) were successfully recanalized by primary PCI were retrospectively analyzed. The 228 patients were divided into 2 groups: myocardial ischemia-reperfusion injury (MIRI) group (n=119) in whom MIRI events occurred within minutes after successful recanalization of IRA, and non-MIRI group (n=109). The 119 patients in MIRI group were further divided into 3 subgroups: severe bradycardia with hypotension (brady-arrhythmia subgroup), lethal ventricular arrhythmias requiring electrical cardioversion (tachy-arrhythmia subgroup), and IRA antegrade flow less than or equal to TIMI 2 grade without angiographic evidence of abrupt closure (no-reflow subgroup).


RESULTS
(1) Clinical and angiographic data: Compared with non-MIRI group, MIRI group was characterized by more inferior infarct location, shorter ischemic duration, more frequently right coronary artery as IRA, more diseased vessels, more often TIMI 0 grade of initial antegrade flow in IRA, less pre-infarction angina, more renal insufficiency, and higher in-hospital mortality (13.4% vs. 4.6%, P=0.021). (2) The peak CK level was remarkably lower in brady-arrhythmia subgroup than that in non-MIRI group (2010 IU/L vs. 2521 IU/L, P=0.039). The peak CK or CK-MB level was notably higher in no-reflow subgroup than in non-MIRI group (4573 IU/L, 338 IU/L, respectively, P=0.000). (3) Left ventricular ejection fraction in no-reflow subgroup was significantly lower than in non-MIRI group (38.7% +/- 8.3% vs. 51.2% +/- 8.1%, P=0.000), left ventricular end-diastolic volume in no-reflow subgroup was greater than that in tachy-arrhythmia subgroup [(135 +/- 32) ml vs. (105 +/- 19) ml, P=0.029].


CONCLUSIONS
Reperfusion arrhythmias may imply the existence of much survived myocardium and do not enhance myocardial damage, while no-reflow increases myocardial injury and induces permanent impairment of cardiac function.
Luo
Yi
Y
Department of Cardiology, Guangzhou First People's Hospital, Guangzhou 510180, China.
Li
Guang-lian
GL
Pan
Yi-zhi
YZ
Zeng
Chong
C
Lei
Xiao-ming
XM
Liu
Zhen
Z
Feng
Kai-Wei
KW
Pi
Yao-qiu
YQ
Lü
Lei
L
D001145:Arrhythmias, Cardiac / Q000150:complications; D002470:Cell Survival; D006801:Humans; D009203:Myocardial Infarction / Q000628:therapy*; D015425:Myocardial Reperfusion; D015428:Myocardial Reperfusion Injury / Q000209:etiology; D009206:Myocardium / Q000201:enzymology; D012189:Retrospective Studies