Nonfluoroscopic catheter ablation of paroxysmal atrial fibrillation.

AIMS: Radiofrequency catheter ablation of atrial fibrillation (AF) is one of the most complex ablation procedures. Both patients and operators are exposed to scattered radiation. This study evaluated the safety and efficacy of intracardiac echo (ICE)-guided pulmonary vein isolation (PVI) without fluoroscopy. METHODS: We retrospectively analyzed the data of 481 consecutive patients with paroxysmal AF undergoing radiofrequency PVI with the CARTO 3 system (Biosense Webster, Diamond Bar, CA, USA). ICE-guided PVI without fluoroscopy and without CT/MRI integration (Nonfluoro group) was performed for 245 patients, and conventional fluoroscopy-guided PVI (Fluoro group) was performed for 236 patients. The primary safety endpoint was the incidence of major adverse events. The primary efficacy endpoint was freedom from AF during follow-up. Secondary endpoints included procedure duration, fluoroscopy duration, and acute PVI rate. RESULTS: Mean procedure times between groups were similar (108.8 ± 18.2 minutes in the Non-fluoro group vs 113.6 ± 26.8 minutes in the Fluoro group; P  =  not significant [NS]). Acute PVI was achieved in all patients, with mean radiofrequency application times of 43.4 ± 7.5 and 44.4 ± 10.7 minutes for the Nonfluoro and Fluoro groups, respectively (P  =  NS). The incidence of cardiac tamponade was 1.2% (3/245 patients) in the Nonfluoro group and 0.8% (2/236 patients) in the Fluoro group (P  =  NS). During 15.2 ± 4.1 months of follow-up, after a single procedure, AF recurrence was documented in 65 of 245 (26.5%) patients and 61 of 236 (25.8%) patients in the Nonfluoro and Fluoro groups, respectively (P  =  NS). CONCLUSIONS: Nonfluoroscopic ICE-guided catheter ablation of AF without prior cardiac image integration or angiography is feasible and safe. PVI without fluoroscopy did not affect procedure duration or long-term efficacy.

Comparison of strategies for catheter ablation of focal atrial tachycardia originating near the His bundle region.

BACKGROUND: Recent studies have suggested that para-Hisian atrial tachycardia (AT) can be successfully ablated from the right atrium (RA), left atrium (LA), or noncoronary cusp (NCC) in the aorta; however, the best approach remains unclear. OBJECTIVE: This study aimed to compare different approaches to radiofrequency catheter ablation (RFCA) of para-Hisian AT. METHODS: We retrospectively analyzed 68 consecutive patients (49[72%] women; mean age 61 ± 13 years) treated with RFCA for this type of AT. Mapping of the RA (n = 68), LA (n = 21), and NCC (n = 52) was performed during AT to identify the earliest activation site and to apply RFCA. RESULTS: RFCA successfully terminated AT in the RA in 13 of 28 patients (46.4%), in the LA in 4 of 16 patients (25.0%), and in the NCC in 46 of 52 patients (88.5%) after 1 procedure (P < .05). Atrioventricular block occurred only during RFCA in the RA in 4 of 28 patients (14.3%). After a mean follow-up of 33.5 ± 25.4 months, AT recurrence was observed in 5 of 13 patients (38.5%) ablated in the RA, 1 of 4 (25.0%) ablated in the LA, and 2 of 46 (4.4%) ablated in the NCC (P < .05). RFCA in the LA was effective only if the local activation time (LAT) was earlier than that in the RA. RFCA in the NCC was successful regardless of the LAT (P < .05). CONCLUSION: Mapping and ablation in the NCC should be always considered in cases of AT originating from the His bundle region, regardless of the LAT.

Study of genetic markers of cardiac arrhythmias in Kazakhstan.

INTRODUCTION: Cardiac arrhythmias are the most common cause of mortality and sudden cardiac death worldwide. In the past decade, genetic factors underlying arrhythmogenic diseases have been revealed and given novel insights in to the understanding and treatment of arrhythmias predisposing one to sudden cardiac death. MATERIAL AND METHODS: We conducted a pilot genetic screening of two patients with catecholaminergic polymorphic ventricular tachycardia (CPVT) and 14 patients with ventricular tachycardia (VT) for genetic variants in the human ryanodine receptor gene 2 (hRYR2). The most relevant 45 hot-spot exons of hRYR2 were amplified by polymerase chain reaction (PCR) and directly sequenced. RESULTS: One novel mutation in a CPVT patient (c.A13892T; p.D4631V) and a novel mutation in a VT patient (c.G5428C; p.V1810L) were identified. Both variants are located at phylogenetically conserved positions and predicted pathogenesis. Three known synonymous SNPs (rs3765097, rs2253273, and TMP ESp1 237664067) were detected in the study group. No further variants within the target regions were detected in the study group. CONCLUSION: The results of study can be applied to risk asssessment for life-threatening arrhythmias and assist in development of appropriate strategies for prevention of sudden cardiac death. The implementation of these strategies would assist in the management of patients with genetically determined arrhythmias in Kazakhstan.