Cardiomyopathy associa ted with ventricular pre-excitation or dissynchronous cardiomyopathy in patients with asymptomatic and symptomatic Wolff-Parkinson-White syndrome: personal experience in patient management

Aim . To study the causal relationship between the functioning of accessory pathway and changes in intraventricular hemodynamics in patients with dissynchronous cardiomyopathy. Methods . The study included 83 patients with registered preexitation according to ECG data. Patients were divided into study and control group. The study group included 33 patients with diagnosed echocardiographic signs of dissynchronous cardiomyopathy (reduced ejection fraction (EF), increased chamber volume and/or decreased global longitudinal strain (GLS) of the left ventricle (LV)). The control group included 50 patients with Wolff-Parkinson-White syndrome/ phenomenon without dissynchrony. Results . After radiofrequency ablation (RFA), patients in the study group showed natural normalization of the QRS complex width and LV GLS. The median QRS width before RFA was 110 ms [100; 120] and after RFA 70 ms [60; 80] (p<0.0001). The median LV GLS before RFA was -18.2% [-19.1; -17] and after RFA -21.3% [-23; -19.2] (p<0.0001). Despite the absence of statistically significant differences in the QRS width in patients in the study and control groups, statistically significant differences in the size and LV EF were revealed. In the study group, the median of end-diastolic volume (EDV) of LV (as a percentage of the parameter from the individual predicted norm) was 112% [102; 123] and EF was 64% [55; 65], and in patients from the control group 102% [97; 112] and 65% [64; 66], respectively. The level of significance of the differences for EDV was p=0.0183, for EF it was p=0.0003. Conclusion . Risk factors of dissynchronous cardiomyopathy (age of patients, right-sided localization of accessory pathway, severity of ventricular preexcitation) are probably of important clinical significance, but are not specific.