Efficiency of Electrical Cardioversion of Paroxysmal Atrial Fibrillation in the Use of Bipolar QuasiSinusoidal Impulse in Patients with Coronary Heart Disease

Abstract

Objective: to study the dose-dependent efficacy of bipolar quasisinusoidal (BPQS) impulse in eliminating 24—48-hour atrial fibrillation (AF) in patients with different clinical forms and course of coronary heart disease (CHD) and different transthoracic resistance (TTR). Subjects and method. Ninety-seven patients (103 AF episodes) who had undergone transthoracic electrical cardioversion (ECV) with a BPQS impulse according to the protocol of dose escalation (from 1—2 to 5 discharges) were analyzed. The discharge power range was from ≤40—65 to 195 J. The diameter of electrodes was 12 cm; its location was anterolateral. Results. Elimination of 70% of the AF episodes required 1—2 discharges; that of 18.3 and 11.7% of the episodes needed 3 and 4—5 discharges, respectively. Low-power (40—85 J) discharges were found to be highly effective (90%) in eliminating 24-hour AF; ~90% ECV success was recorded in patients with 28—48-hour episodes when greater power (≤115 J) discharges were applied to 17% of the patients. The total success rate for cardioversion was 94.2%; that of emergency ECV was 81% (p=0.022). The ECV success rate was 88.6% in patients with clinically relevant and severe (acute chronic) heart failure (HF), 98% in those with mild HF and without its clinical signs (p<0.05), and 83% in those with acute myocardial infarction. The patients with acute and chronic alveolar lung edema and hydrothorax were recorded to have the lowest BPQS impulse efficacy (73.5% (by 24.3% less than those without lung edema and hydrothorax)) (p<0.001). It was ascertained that TTR was in the range of 70 to 142 ohms (versus the lowest values) substantially decreased the efficacy of smaller power (as high as ~70 J) discharges.Conclusion. The findings are indicative of the high (90%) efficacy of low-power (≤85—115 J) discharges of the BPQS pattern while eliminating 24—48-hour AF in patients with different clinical forms and course of CHD. There was an association between the severity of HF and the success of ECV and between TTR and the efficacy of low-power (as high as ~70 J) discharges.

Keywords

• electrical cardioversion, bipolar quasi-sinusoidal impulse, atrial fibrillation