Abstract

The most common strategies in the managementof atrial fibrillation (AF) involve electrical cardioversion andpharmacological agents. Bisoprolol is a high selective β1-adrenoceptor blocker used for ventricular rate control and tohelp maintain sinus rhythm. In a retrospective study we comparedECG frequency domain variables between patients whounderwent a successful electrical cardioversion and those thatwere unsuccessful. As well as this we assessed whether therewas a difference in these variables for patients who underwent electrical cardioversion while on bisoprolol. Signal processingwas performed on 51 patients undergoing electrical cardioversion:bandpass filtering (0.5-50Hz), QRST cancellation andfrequency analysis. An incremental defibrillation energy protocolwas delivered until cardioversion or up to a maximumlevel of 200 [J]. The study indicated a significant difference inthe dominant AF frequency for long segments (DAFF_L) betweencardioverted and non-cardioverted subgroups, employingan energy less or equal to 100 Joules respectively: (5.5391 ±1.0396) [Hz] vs. (6.0859 ±0.8071) [Hz] (n=48, p = 0.048), and inpatients on bisoprolol: (5.5250 ±1.0302) [Hz] vs. (6.4489±0.5828) [Hz] (n=26, p = 0.008). Also, the energy required forsuccessful cardioversion was significantly lower for patients onbisoprolol: (110.00 ± 27.77) [J] vs. (129.41 ±30.92) [J], p=0.046.Also, there was a positive correlation between the DAFF_Land the minimal energy necessary for successful cardioversion( =0.434, p=0.007); a better correlation was obtained for patientson bisoprolol ( =0.575, p=0.005). Therefore, analysis ofDAFF_L on Lead II can be a useful indicator for predictingdefibrillation success in AF patients undergoing transthoracicelectric cardioversion, and there is a positive incidence of Bisoprololupon the values of DAFF_L and electrical cardioversionsuccess at minimal shock energy.