Comparing Safety and Efficacy of Irrigated Radiofrequency Catheter Ablation Versus Combined Cryoballoon and Catheter Ablation for Persistent Atrial Fibrillation.

Background: Catheter and cryoballoon ablation are established treatments for atrial fibrillation. Frequently, substrate modification of the left atrium is performed in patients with persistent AF or evidence of left atrial adverse remodeling. We compared one year outcomes of AF ablation with substrate modification utilizing radiofrequency catheter ablation (RFA) compared to a combination of cryoballoon ablation with radiofrequency catheter ablation (HAFA). Methods: Ablation for persistent AF was performed using stand-alone catheter ablation (RFA group, n=31) or cryoballoon for pulmonary vein isolation with RFA catheter ablation for substrate modification (HAFA group, n=21) and procedural and clinical outcomes were analyzed. Pulmonary vein isolation and LA substrate modification including creation of left atrial ablation lines and/or CFAEs was performed in all patients. Patients were followed for up to one year. A three- month blinding window was applied for analysis. Results: Clinical characteristics were similar between groups. Total procedure (244.15±64.7 vs 235.5±54.6, p=0.6) and fluoroscopy time (37±15.4 vs 29.5±15.7, p=0.96) were not different between the HAFA and RFA groups, respectively. Periprocedural complications were similar among groups. AF free survival was not significantly different between Conclusions: Combined cryoballoon and catheter ablation for LA substrate modification (HAFA) has similar safety and efficacy compared to stand-alone catheter ablation for persistent AF. Recurrent atrial flutter is more frequently observed after cryoballoon ablation for persistent AF.

Frequency of serious arrhythmias detected with ambulatory cardiac telemetry.

Ambulatory cardiac telemetry has been shown to be effective in establishing diagnoses in patients with suspected arrhythmias. A critical component of ambulatory telemetry is the immediate transfer of rhythm information to a central monitoring station without requiring patient action. The frequency with which potentially life-threatening events are detected using ambulatory telemetry has not previously been evaluated in a large patient population. All patients (n = 26,438) who underwent monitoring from April to December 2008 at a single service provider formed the patient population of this study. Arrhythmic events noted in these patients were defined as those requiring physician notification and those that represented potentially life-threatening arrhythmias. Of the 26,438 patients included in the study, 5,459 (21%) had arrhythmic events meeting physician notification criteria during a mean monitoring period of 21 days. Of these, 262 patients (1%) had arrhythmic events that could potentially be classified as emergent. These included 120 patients with wide complex tachycardia > or = 15 beats at > or = 120 beats/min, 100 patients with pauses > or = 6 seconds, and 42 patients with sustained heart rates <30 beats/min. An additional 704 patients (3%) had narrow complex tachycardia > or = 180 beats/min at rest. In conclusion, approximately 1% of patients who underwent ambulatory telemetry for routine clinical indications experienced life-threatening arrhythmic events over a 3-week monitoring period. Ambulatory cardiac telemetry could be potentially lifesaving in this group of patients.