Novel algorithms for improved lesion visualization utilizing electroanatomic mapping during pulmonary vein isolation

Background and aims

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Recently, high-power short-duration (HPSD) ablation protocols have been introduced to clinical practice. Electroanatomic mapping is the gold standard when HPSD ablation is performed. Visualization of lesion creation by HPSD ablation may be challenging for electroanatomic mapping systems due to short ablation application durations, especially when catheter positions are unstable. Nevertheless, the effectiveness of catheter ablation relies on transmurality and contiguity of ablation lesions and therefore optimal lesion visualization during ablation procedures is of great importance. Two novel algorithms have recently been incorporated into a commercially available electroanatomic mapping system facilitating continuous analysis of catheter movement during HPSD ablation and offering automated display of interlesion gaps to enable optimized lesion creation. We investigated the impact of this novel algorithms on procedural parameters in patients undergoing first-time PVI with HPSD ablation.

Methods

Consecutive patients undergoing first-time PVI with two different laboratory setups were evaluated. Ablation was performed in all patients with HPSD ablation containing of applications of 90 Watt over 4 seconds and under guidance of high-density mapping utilizing an octaspline mapping catheter. In the study group the novel algorithm was utilized. In case of automated interlesion gap display additional touch-up ablation was performed. A patient cohort without movement analysis and in which interlesion distance was manually assessed by the operator served as control group.

Results

A total of 86 patients were analyzed (28 in the study group and 58 in the control group). PVI was successful in all patients. In three cases additional ablation of the cavotricuspid isthmus was conducted and in three cases additional lesions were created for the treatment of organized atrial tachycardias which occurred during the interventional procedures. No major periprocedural complications occurred in both groups. Procedural duration (83±19 minutes in the study group and 75±19 minutes in the control group, P=0.11, Figure 1 A), fluoroscopy duration (314±149 seconds versus 315±147 seconds, P=0.98, Figure 1 B), radiofrequency (RF) ablation times for isolation of right and left pulmonary veins (376±171 seconds versus 357±102 seconds, p=0.55, Figure 1 C) and numbers of RF applications (93.9±42.8 applications versus 89.4±25.5 applications, P=0.55, Figure 1 D) were comparable between patient cohorts. First-pass isolation of all pulmonary veins (PVs) was significantly more often achieved in the study group as compared to the control group (22/28 patients (78.6 %) versus 28/58 patients (48.3 %), P=0.008, Figure 1 E). There was no significant difference among first-pass isolation rates for right PVs (24/28 patients (85.7%) versus 43/58 patients (74.1%), P=0.23) and for left PVs (24/28 patients (85.7% %) versus 36/58 patients (62.1 %), P=0.25).

Conclusion

The integration of novel algorithms for continuous catheter movement analysis and automatic interlesion gap visualization can lead to higher first-pass isolation rates of HPSD ablation without increase of the number of RF applications as compared to standard mapping algorithms. The impact of these tools on long-term clinical effectiveness of AF ablation have to be evaluated in further studies.

Figure 1