Papadopoulos Christodoulos E, Karvounis Haralampos I, Parharidis Georgios E, Louridas Georgios E
First Department of Cardiology, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece.
Ann Noninvasive Electrocardiol. 2003 Oct;8(4):275-83. doi: 10.1046/j.1542-474x.2003.08403.x.
Preinfarction angina (PA) consists a strong clinical correlate to ischemic preconditioning (PC) and seems to occur in a bimodal time course. The aim of the study is to evaluate the impact of both forms of PC on QTc value representing myocardial electric stability, in patients with a first NSTEMI.
Forty-eight patients, with first NSTEMI and poor or no collateral development were enrolled in the study. QTc at admission and discharge were recorded. All patients had comparable admission QTc values and were divided into three groups according to the absence or presence and exact timing of preinfarction angina. The first group consisted of 20 patients who did not report PA (PA-, representing no PC effect); the second group of 12 patients with reported PA within 12 hours prior to admission (12h PA+, representing the classic form of PC); and the third group of 16 patients reporting PA within 12 to 48 hours prior to admission (48-hour PA+, representing the delayed form of PC). The primary outcome was determined as the effect of PA on QTc value at discharge.
Discharge QTc values were significantly reduced in both (PA+) groups compared to (PA-) group (412 +/- 50 vs. 455 +/- 53 ms, p = 0.015 and 417 +/- 29 vs. 455 +/- 53 ms, P = 0.033, respectively). Both groups of (PA+) patients compared to (PA-) patients suffered no arrhythmic events during their hospitalization (0/12 vs. 6/20, P = 0.04 and 0/16 vs. 6/20, P = 0.02).
Both forms of preconditioning, similarly and significantly reduce QTc value at discharge in patients experiencing a first NSTEMI, suggesting possible protection from future arrhythmic events.
梗死前心绞痛（PA）与缺血预处理（PC）存在密切的临床关联，且似乎呈双峰时间进程出现。本研究旨在评估两种形式的PC对首次非ST段抬高型心肌梗死（NSTEMI）患者代表心肌电稳定性的QTc值的影响。
48例首次发生NSTEMI且侧支循环发育不良或无侧支循环的患者纳入本研究。记录入院时和出院时的QTc值。所有患者入院时的QTc值具有可比性，并根据是否存在梗死前心绞痛及其确切时间分为三组。第一组由20例未报告PA的患者组成（PA-，代表无PC效应）；第二组为12例入院前12小时内报告有PA的患者（12小时PA+，代表经典形式的PC）；第三组为16例入院前12至48小时内报告有PA的患者（48小时PA+，代表延迟形式的PC）。主要结局确定为PA对出院时QTc值的影响。
与（PA-）组相比，两个（PA+）组的出院QTc值均显著降低（分别为412±50 vs. 455±53 ms，p = 0.015；417±29 vs. 455±53 ms，P = 0.033）。与（PA-）组患者相比，两个（PA+）组的患者在住院期间均未发生心律失常事件（0/12 vs. 6/20，P = 0.04；以及0/16 vs. 6/20，P = 0.02）。
两种形式的预处理均同样显著降低首次发生NSTEMI患者出院时的QTc值，提示可能对未来心律失常事件具有保护作用。
