ASSESSMENT OF SYSTOLIC FUNCTION AND DYSSYNCHRONY PARAMETERS IN PATIENTS WITH MYOCARDIAL INFARCTION

Aim. To investigate the parameters of systolic function in patients with acute Q-wave myocardial infarction (AMI), comparing the results of two-dimensional echocardiography (2D EchoCG), three-dimensional real-time EchoCG (3D EchoCG), and computed tomography (CT) as a verification method. To study the parameters of dyssynchrony, which develops due to mechanic myocardial heterogeneity in AMI patients. Material and methods. In total, 82 patients (61 men and 21 women; mean age 52±21 years) were examined within the first 6 days of AMI. The comparison group, comparable by age and sex, included 65 individuals without clinically manifested cardiovascular pathology. All participants underwent standard examinations, electrocardiography (ECG), 24-hour ECG monitoring, EchoCG, angiography, and CT. Mechanic dyssynchrony was assessed by dispersion of the time to the minimal volume of 16 segments (strain dyssynchrony index, SDI). Results. The difference for end-diastolic volume (EDV; 2D vs. 3D EchoCG and 2D EchoCG vs. CT) was statistically significant (respective p-values 0,014 and <0,005). Ejection fraction (EF) and local contractility index (LCI) were significantly different for 2D vs. 3D EchoCG (>p=0,0002 and <0,005, respectively). EF values were similar for 3D EchoCG and CT (>p=0,3). SDI values in AMI patients were significantly higher than in the comparison group participants (6,8±2,7% vs. 2,9±1,6%; p<0,001). In patients with anterior AMI, the SDI differences were observed for one vs. two-vessel (p<0,05) and one vs. three-vessel pathology (>< 0,05) and one vs. three-vessel pathology (p<0,005), but not for two vs. three-vessel pathology.><0,005), but not for two vs. three-vessel pathology. Patients with inferior AMI did not demonstrate any marked differences in SDI values. Among patients with SDI >5,1, the incidence of clinical complications (pulmonary edema, ventricular fibrillation, high-grade atrioventricular block) was higher by 55% (p<0,05; ><0,05 r=0,35). SDI was also associated with high-grade ventricular arrhythmias (p<0,005; ><0,005r=0,48). Conclusion. Three-dimensional visualization provides an opportunity to assess systolic function parameters more accurately. SDI values were linked to the number of affected coronary vessels. The significance of the observed differences was related to AMI localization. SDI could be regarded as a determinant of both mechanical myocardial heterogeneity and the risk of clinical and arrhythmic complications in AMI.

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