The aim – to study heart structure and function according to the results of MR and ultrasound imaging, heart rate variability parameters, immune status indices in patients with myocarditis and to detect prognostic markers of unfavorable myocarditis clinical course.
Material and methods. Fifty two patients with clinically suspected acute diffuse myocarditis, sinus rhythm and heart failure with reduced LV ejection fraction (LV EF ≤ 40 %), among them 30 men and 22 women were examined. They were divided into two groups: 1st group – 27 patients with recovery of left ventricular ejection fraction (> 40 %) in 12 months, 2nd group – 25 patients without restoration of myocardial contractile function (LV EF ≤ 40 %). Within the 1st month after disease onset and after 12 months magnetic resonance imaging (MRI) of the heart, transthoracic echocardiography, Holter ECG monitoring with HRV parameters and examination of the immune status were performed.
Results. Left ventricular ejection after 12 months observation in patients of the 1st group increased by 27.8 % (P<0.01) and averaged 48.7 %, in patients of the 2nd group – by 12.4 % (P>0.05), on average to 38.5 %. Within the 1st month after myocarditis onset, myocardial edema at MRI was detected in 100 % and early contrast accumulation – in 92.3 % of patients (n=48). After 12 months of follow-up, both study groups were comparable by the results of detection of myocardial edema (18.5 and 20 %, respectively), and early contrast accumulation (22.2 and 28 %, respectively). The amount of delayed contrast accumulation zones at 12 months was significantly higher in patients in the second group – 42 (80.7 %) and 45 (86.5 %). The SDNN indicator in the 1st group increased by 18.3 % (P<0.05) for 12 months, while in the 2nd group it increased by 9.6 % (P>0.05). Number of ventricular arrhythmias and episodes of an unstable ventricular tachycardia after 12 months in patients of the 2nd group almost 2 and 2.5 times (P<0.01) respectively, exceeded the similar indicators of the 1st group. Conclusions. In patients with myocarditis, in which LV EF remained ≤ 40 % after 12 months, significantly greater amount of delayed contrast accumulation and a decrease of HRV parameters were noted, related to more frequent development of ventricular arrhythmias. Patients with myocarditis having sites with delayed MRI accumulation of contrast, had a significantly higher risk of developing episodes of unstable ventricular tachycardia after 12 months of follow-up, according to Fisher’s exact test (F=0.012, OR=6.88).