Methods: Out of 200 patients who underwent robotically guided ablation for AF between 2007 and 2009 at our institute, 100 patients (29 women, age 56.5 �� 10 years) had paroxysmal AF refractory to antiarrhythmic drugs. Electroanatomic mapping using NavX system (St. Jude Medical) provided anatomical shell for subsequent circumferential ablation with robotic catheter (Artisan) loaded with a 3.5-mm, open-irrigation, cooled-tip ablation catheter. Results: A mean of 69 radiofrequency current applications (duration 2082 �� 812 seconds) were delivered to achieve circumferential electrical isolation of pulmonary venous antra. Total procedural time reached 222 �� 54 minutes. The mean fluoroscopic time was 11.9 �� 7.8 minutes. There were no major procedure-related complications. After a median follow-up of www.selleckchem.com
15 months (range 3-28 months), 63% of the patients were free from any atrial arrhythmias �� 30 seconds after the single INPP5D
procedure. Success rate increased to 86% after 1.2 procedures. Multivariate analysis revealed that only predictor of recurrent AF/AT was shorter overall procedural time (207 �� 36 vs 236 �� 64 minutes in patients with and without recurrences, respectively, P = 0.0068). Conclusions: This study demonstrates feasibility and safety of robotic navigation in catheter ablation for paroxysmal AF. Midterm follow-up documents success rate comparable to other technologies and potential for improvement in more extensive ablation along the ridges with thicker myocardium. (J Cardiovasc Electrophysiol, Vol. 22, pp. 534-540 May 2011) ""Beta-Blockers and Microvolt T-Wave Alternans.?Introduction: Results of microvolt T-wave alternans (MTWA) studies vary and may be influenced by whether beta-blocker therapy was withheld prior to MTWA assessment. We conducted a meta-analysis of the predictive value of MTWA screening for ventricular arrhythmic events in primary prevention patients with left ventricular dysfunction and examined whether results differed depending upon whether beta-blocker use was withheld prior to MTWA testing. Methods and Results: Prospective studies that evaluated whether MTWA predicted ventricular arrhythmic events published between January 1980 and September 2008 were identified. Summary estimates for the predictive value of MTWA were derived with random-effects Cisplatin research buy
models. Nine studies involving 3,939 patients were identified. Overall, an abnormal MTWA (positive and indeterminate) test was associated with an almost 2-fold increased risk for arrhythmic events (pooled RR = 1.95, 95% CI: 1.29�C2.96; P = 0.002). However, significant heterogeneity across studies was observed (P = 0.024). In the 4 studies in which beta-blocker therapy was not withheld prior to MTWA assessment, an abnormal MTWA test was associated with a 5-fold increased risk for arrhythmic events (pooled RR = 5.39, 95% CI: 2.68�C10.84; P < 0.001) and was robust to sensitivity analyses.