[Przezskórne zamknięcie ubytku w przegrodzie międzyprzedsionkowej: wpływ na prawy przedsionek, dyspersję załamka P i zaburzenia rytmu serca w obserwacji średnioterminowej].

: The size of the right atrium (RA) reduces after transcatheter closure of the atrial septal defect (ASD). Inverse structural and electrical remodeling is observed. AIM: The aim of study was to analyze the parameters predisposing to the lack of normalization of enlarged RA after transcatheter closure of ASD during 6-month follow-up. MATERIALS AND METHODS: A prospective study included 56 consecutive adult patients (12 men) aged from 23 to 76 years (49.8±13.3 years) with ASD, in whom transcatheter ASD closure was performed. Each patient was assessed before and 6 months after the treatment using standard 12-lead resting electrocardiogram (ECG), 24-hour Holter monitoring and echocardiography. RESULTS: Before the procedure in 37 patients with ASD enlarged RA was observed, while after transcatheter ASD closure in 24 patients normalization of enlarged RA was noted. Patients in whom 6 months after the procedure there was no normalization of the enlarged RA were older, characterized by higher right ventricular systolic pressure (RVSP), pulmonary to systemic blood flow ratio (Qp/Qs), larger size of the occluder, interatrial septal defect, longer fluoroscopy time and lower left ventricular ejection fraction. P-wave dispersion (Pdysp) was found to be a destimulant i.e. increased Pdysp (>67 ms, P 72ms, P<0.000) increased the chance of RA normalization. A significant association was found between the reduction of supraventricular extrasystolic beats and RA area normalization (P<0.001), and there was no association between the incidence of atrial fibrillation episodes and RA area normalization. CONCLUSIONS: Evaluation of the duration of the P-wave and its dispersion may help to assess the prognosis of the right atrium size normalization in the mid-term follow-up after transcatheter closure of ASD. There is a significant relationship between normalization of the right atrium size and reduction of supraventricular extrasystolic beats.