The utility of a novel mapping algorithm utilizing vectors and global pattern of propagation for scar-related atrial tachycardias.

BACKGROUND: Activation maps of scar-related atrial tachycardias (AT) can be challenging to interpret due to difficulty in inaccurate annotation of electrograms, and an arbitrarily predefined mapping window. A novel mapping software integrating vector data and applying an algorithmic solution taking into consideration global activation pattern has been recently described (Coherent™, Biosense Webster "Investigational"). OBJECTIVE: We aimed to assess the investigational algorithm to determine the mechanism of AT compared with the standard algorithm. METHODS: This study included patients who underwent ablation of scar-related AT using the Carto 3 and the standard activation algorithm. The mapping data were analyzed retrospectively using the investigational algorithm, and the mechanisms were evaluated by two independent electrophysiologists. RESULTS: A total of 77 scar-related AT activation maps were analyzed (89.6% left atrium, median tachycardia cycle length of 273 ms). Of those, 67 cases with a confirmed mechanism of arrhythmia were used to compare the activation software. The actual mechanism of the arrhythmia was more likely to be identified with the investigational algorithm (67.2% vs. 44.8%, p = .009). In five patients with dual-loop circuits, 3/5 (60%) were correctly identified by the investigational algorithm compared to 0/5 (0%) with the standard software. The reduced atrial voltage was prone to lead to less capable identification of mechanism (p for trend: .05). The investigational algorithm showed higher inter-reviewer agreement (Cohen's kappa .62 vs. .47). CONCLUSIONS: In patients with scar-related ATs, activation mapping algorithms integrating vector data and "best-fit" propagation solution may help in identifying the mechanism and the successful site of termination.

Recurrent Atrial Fibrillation After Initial Long-Term Ablation Success: Electrophysiological Findings and Outcomes of Repeat Ablation Procedures.

BACKGROUND: Atrial fibrillation recurrence after initial long-term success of catheter ablation has been described, yet not well studied. We assessed the electrophysiological findings and outcomes of repeat ablation procedures in this setting. METHODS AND RESULTS: Between 2000 and 2015, 10 378 patients underwent atrial fibrillation ablation and were enrolled in a prospectively maintained data registry. From this registry, we included all 137 consecutive patients who had initial long-term success, defined as freedom from recurrent arrhythmia for >36 months off antiarrhythmics, then underwent repeat ablation for recurrent atrial fibrillation. The median arrhythmia-free period that defined long-term success was 52 months (41-68 months). In redo ablations, reconnection along at least one of the pulmonary veins (PVs) was found in 111 (81%) patients. Reconnection along a left superior, left inferior, right superior, and right inferior PV was found in 64%, 62%, 50%, and 54% of patients, respectively, and were reisolated. Additional non-PV ablations were performed in 127 (92.7%) patients: posterior wall (46%), septal to right PVs (49%), superior vena cava (35%), roof lines (52%), and cavotricuspid isthmus (33%). After a median follow-up of 17 months (5-36.9 months), 103 patients (75%) were arrhythmia free (79 off antiarrhythmics, 24 on antiarrhythmics). CONCLUSIONS: PV reconnection is the most common electrophysiological finding in patients with atrial fibrillation recurrence after long-term success, but with lower rates than what had been reported for early recurrences. In our experience, repeat ablations in this setting involve complex ablation approaches to reisolate the PVs and modify the atrial substrate and are associated with good success rates.

Characteristics, treatment, and outcomes of periprocedural cerebrovascular accidents during electrophysiologic procedures.

OBJECTIVES: We sought to identify the characteristics, treatment, and outcomes of periprocedural cerebrovascular accident (PCVA) during electrophysiologic (EP) procedures. BACKGROUND: Periprocedural cerebrovascular accident is one of the most feared complications during EP procedures with very few data regarding its characteristics, management, and outcomes. METHODS: Between January 1998 and December 2008, we reviewed 30,032 invasive EP procedures for PCVA occurrence and characteristics. Management and outcomes were also determined. RESULTS: Thirty-eight CVAs were identified. Twenty (53 %) were intraprocedural and 18 (47 %) postprocedural. Thirty-two (84 %) were classified as strokes and six (16 %) as transient ischemic attacks. All CVAs except one (37, 97 %) were ischemic and the vast majority occurred during ablation procedures (36, 95 %). Among the 31 patients with ischemic stroke, 11 (35 %) were treated with reperfusion (eight catheter-based therapy and three intravenous t-PA) of whom five (46 %) had complete recovery, three (27 %) had partial recovery, and three (27 %) had no recovery. No hemorrhagic transformations occurred. CONCLUSION: Periprocedural cerebrovascular accident during EP procedures is rare and is almost always ischemic. It occurs more frequently during ablation procedures. Reperfusion therapy is feasible and safe.