Two Year, Single Center Clinical Outcome After Catheter Ablation For Paroxysmal Atrial Fibrillation Guided by Lesion Index.

BACKGROUND: This study describes the use of lesion index (LSI) as a direct measure to assess the adequacy of ablation lesion formation with force-sensing catheters in ablation of paroxysmal atrial fibrillation (PAF). LSI is calculated by the formula:LSI = CF (g) ×Current (mA) ×Time (sec). METHODS: Fifty consecutive patients with PAF underwent pulmonary vein (PV) isolation using a catheter dragging technique and targeting different LSI values in different anatomical areas.A force-sensing ablation catheter was used to continuously measure contact force (CF) and guide radiofrequency ablation (RF) lesion formation. Ablation lesions were delivered to achieve an LSI value of 5.0 in posterior locations, 5.5 in anterior locations and 6.0 in the regionbetween the left atrial appendage and left superiorpulmonary vein ridge. Force-time Integral (FTI) was not used to evaluate lesion formation. RESULTS: A single center, retrospective analysis was performed with 196/198 (99%) PVs acutely isolated. The mean procedure time was 134 ± 34 mins and the mean fluoroscopy time was 7.8 ± 3.2 mins. At a mean follow up of two years, 43/50 (86%) of patients were in normal sinus rhythm with no documented recurrences of atrial fibrillation. CONCLUSION: LSI can be used to guide the placement of durable lesion formation with RF ablation using CF catheters in patients with PAF.

Use of Three-dimensional Mapping to Identify an Alternating Atrial Activation Pattern in the Coronary Sinus.

Atypical left atrial flutters present following atrial fibrillation ablation have been well-documented in the literature. These arrhythmias are known to be difficult to localize and ablate. An atypical flutter with an alternating activation pattern in the coronary sinus, however, is unusual and has rarely been discussed. In this case report, we describe the use of high-density three-dimensional anatomic mapping to successfully localize and terminate an atypical flutter with an alternating atrial activation pattern in the coronary sinus.

A novel 3D anatomic mapping approach using multipoint high-density voltage gradient mapping to quickly localize and terminate typical atrial flutter.

PURPOSE: The purposes of the study were to evaluate and characterize the cavotricuspid isthmus using multipoint high density voltage gradient mapping (HD-VGM) to see if this would improve on current ablation techniques compared to standard cavotricuspid isthmus ablation techniques. METHODS: Group 1, 25 patients who underwent ablation using standard methods of 3D mapping and ablation, was compared to group 2, 33 patients undergoing ablation using HD-VGM and ablation. Using this method, we are able to identify the maximum voltage areas within isthmus and target it for ablation. Total procedure times, ablation times and number of lesions, distance ablated, and fluoroscopy times were compared. RESULTS: Fifty-eight patients were included in this study. Compared to group 1, in group 2, HD-VGM decreased the total ablation time 18.2 ± 9.2 vs 8.3 ± 4.0 min (p < 0.0001), total ablation lesions 22.7 ± 18.8 vs 5.5 ± 4.2 (p < 0.0001), and the length of the ablation lesions was significantly shorter 47.0 mm ± 13 mm vs 32.6 mm ± 10.0 mm (p < 0.0001). While the average length of the CTI was similar, 47.0 mm ± 13 mm vs 46.1 mm ± 10.0 mm (p 0.87), in group 2, only 71% of the isthmus was ablated. CONCLUSION: Multipoint high density voltage gradient mapping can help identify maximum voltage areas within the isthmus and when ablated can create bidirectional block with decreased ablation times and length of the lesion.

Catheter ablation of atypical atrial flutter: a novel 3D anatomic mapping approach to quickly localize and terminate atypical atrial flutter.

PURPOSE: This study aims to describe a novel method of High Density Activation Sequence Mapping combined with Voltage Gradient Mapping Overlay (HD-VGM) to quickly localize and terminate atypical atrial flutter. METHODS: Twenty-one patients presenting with 26 different atypical atrial flutter circuits after a previous catheter or surgical AF ablation were studied. HD-VGM was performed with a commercially available impedance-based mapping system to locate and successfully ablate the critical isthmus of each tachycardia circuit. The results were compared to 21 consecutive historical control patients who had undergone an atypical flutter ablation without HD-VGM. RESULTS: Twenty-six different atypical flutter circuits were evaluated. An average 3D anatomic mapping time of 12.39 ± 4.71 min was needed to collect 2996 ± 690 total points and 1016 ± 172 used mapping points. A mean of 195 ± 75 s of radiofrequency (RF) energy was needed to terminate the arrhythmias. The mean procedure time was 135 ± 46 min. With a mean follow-up 16 ± 9 months, 90% are in normal rhythm. In comparison to the control cohort, the study cohort had a shorter procedure time (135 ± 46 vs. 210 ± 41 min, p = 0.0009), fluoroscopy time (8.5 ± 3.7 vs. 17.7 ± 7.7 min, p = 0.0021), and success in termination of the arrhythmia during the procedure (100 vs. 68.2%, p = 0.0230). CONCLUSIONS: Ablation of atypical atrial flutter is challenging and time consuming. This case series shows that HD-VGM mapping can quickly localize and terminate an atypical flutter circuit.