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Background: Atrial fibrillation (AF) is a frequent complication of acute myocardial infarction (AMI), with a reported incidence of 7-18%. The incidence of congestive heart failure, in-hospital mortality, and long-term mortality is higher in AMI patients with AF than in those without. P-wave duration (PWD) on Signal-Averaged ECG is a non-invasive marker of intra-atrial conduction disturbances, which are believed to be the main electrophysiological cause of AF., Material/methods: In the present study we investigated whether PWD can predict development of AF in 130 AMI patients (100 men and 30 women, aged 56.9+/-12). PWD was recorded, along with clinical and hemodynamic characteristics., Results: During the observation period (up to 21 days) 22 patients (16.9%) developed AF. In univariate analysis the variables associated with development of AF were age>65, Killip class III-IV, and PWD>125 ms. Stepwise logistic regression analysis showed that age>65 and PWD>125 ms were independently associated with AF., Conclusions: PWD measured in a very early period of AMI is a useful tool in predicting AF.

Background: Survivors of acute myocardial infarction (AMI) are at increased risk for arrhythmic events (AE), which include sudden death (SD) or sustained ventricular tachycardia (sVT). In the prethrombolytic era, abnormal parameters of depolarization and repolarization were considered to be markers of susceptibility to these events. The purpose of the present study was to assess whether these variables should still be considered predictors of AE in postinfarction patients with normal intraventricular conduction., Material/methods: The study population consisted of 236 survivors of AMI, in whom the parameters of depolarization on SAECG (QRSd, LAS, RMS, LPs) and repolarization on ECG (QTc-max, QTd) were assessed before hospital discharge. The patients were followed for 18 months, and all episodes of SD and sVT were recorded., Results: During long-term observation, 3 patients died from SD, and sVT occurred in 1 patient. Univariate Cox regression analysis showed that among the SA-ECG and ECG variables, only QRSd was significantly related to the incidence of AE (p<0.04). A comparison of event-free survival curves by the Kaplan-Meier method at the dichotomy limit of 119ms showed significantly worse prognosis in patients with QRSd> or =119ms (p<0.01)., Conclusions: In postinfarction patients with normal intraventricular conduction treated in the acute and chronic phase of MI according to recent management strategies, QRSd> or =119ms on SAECG is associated with arrhythmic events. Other parameters of depolarization, such as LAS, RMS, and positive LPs, and also repolarization, such as prolonged QTc-max and QTd, seem to be of little use in predicting these events.

Background: In survivors of acute myocardial infarction (AMI), an occluded infarct-related artery (IRA) is an important predictor of cardiac death (CD) and sudden death (SD). Early reperfusion of the IRA was associated with improved survival rate. The purpose of the present study was to assess if late IRA revascularization, performed 10-30 days after AMI, also has a beneficial effect on the incidence of CD and SD during an 18-month follow-up., Material/methods: The study population consisted of 93 post-MI patients with occluded IRA on coronary angiography. The patients were divided into 2 groups according to IRA status at discharge -- revascularized (47 patients) or occluded (46 patients) -- and followed. Before revascularization, the two groups of patients did not differ in the prevalence of clinical and angiographic variables, or in the incidence of risk factors for SD. In patients who underwent angioplasty or bypass graft surgery of closed IRA, the markers of electrical instability demonstrated no significant improvement after revascularization., Results: During the 18-month follow-up a significantly lower incidence of CD (0% vs 15%, p<0.01) and SD (0% vs 11%, p<0.03) was observed in the group of patients with revascularized IRA than in the group of patients with occluded IRA., Conclusions: In survivors of AMI, late reperfusion of occluded IRA is associated with reduced 18-month cardiac mortality. The beneficial effect of this procedure on the incidence of sudden death, not associated with improvement in myocardial electrical stability, suggests that ischemia can be considered an important factor modulating the arrhythmogenic substrate.

QT interval prolongation is discussed as a possible risk factor of dangerous arrhythmias. The aim of this study was to evaluate the influence of different interventional treatment of coronary artery disease in patients after myocardial infarction on QT interval duration. Two groups of patients were analyzed. The first group (G1) consisted of 37 patients in whom PTCA was performed; the second group (G2)--42 pts after surgical myocardial revascularisation (CABG). The 24-hour electrocardiography monitoring was performed in all the patients. Results were analyzed especially considering the average daily values of QT, QTp, QTc and RR duration. In patients after CABG we observed statistically significant prolongation of QTc interval duration what was not noticeable in patients after PTCA. The cardiosurgical procedure of coronary by-pass grafting in patients with coronary artery disease after the myocardial infarction in contrary of PTCA may lead to significant prolongation of QTc interval duration. This problem needs further investigation.