CHANGE OF ARRHYTHMIC EVENTS IN ACUTE MYOCARDIAL INFARCTION WITH ST-SEGMENT ELEVATION AFTER PHARMACOINVASIVE REVASCULARIZATION

Abstract

Aim. To study changes in course of arrhythmias, depending on the efficacy of coronary blood flow restoration due to pharmacoinvasive revascularization in patients with ST segment elevation myocardial infarction (STEMI).Material and methods. STEMI-patients (n=117) with an effective (according to ECG criteria) thrombolytic therapy (TLT) and the subsequent (after 3-24 hours) percutaneous coronary intervention (PCI), were included into the study. Telemetry ECG was performed before and after PCI with analysis of the arrhythmias and cardiac conduction disorders.Results. Patients (n=84; 71.8%) with an effective TLT, confirmed by the coronary angiography (CAG), and with subsequent effective PCI were included into the group "without rethrombosis" (RT(–)). Patients (n=33; 28.2%) with CAG proven rethrombosis of the infarct-related coronary artery and subsequent effective PCI were included into the group "with rethrombosis" (RT(+)). Regardless of the stability of coronary blood flow restoration after the TLT, PCI was associated with an increased incidence of ventricular tachycardia (VT) (p<0.01), sinus tachycardia (p=0.01), paroxysmal supraventricular tachycardia (SVT) (p<0.05) and paired ventricular extrasystoles (p<0.01). Compared to the RT(–) group, in the RT(+) group after PCI VT were recorded more frequently (44% vs 63.6%, respectively; p<0.05) as well as AV-block 3 degree (3.6% vs 12.1%, respectively; p<0.05). Episodes of sinus tachycardia were detected significantly more frequently before PCI in RT(–) group compared with RT(+) group (67.9% vs 45.4% respectively; p<0.01). The number of patients with episodes of sinus bradycardia increased (from 19% to 32.1%; p=0.02) after PCI in RT(–) group.Conclusion. The incidence of VT and SVT paroxysms, episodes of sinus tachycardia, atrioventricular conduction disturbances and ventricular extrasystoles increased in all patients after the effective PCI due to reperfusion. However, VT episodes and paroxysmal atrioventricular block grade 3 were more common in patients with previous re-thrombosis of the infarct-related coronary artery. Considering a high risk of arrhythmic events, continuous ECG mon itoring with automated alarm systems about life-threatening arrhythmias should be applied in STEMI patients regardless of tactics of coronary blood flow restoration and the reperfusion effectiveness.

Keywords

• acute myocardial infarction
• reperfusion
• revascularization
• rethrombosis
• arrhythmia
• ventricular tachycardia
• ventricular fibrillation