Efficacy of advanced pace-mapping technology for idiopathic premature ventricular complexes ablation

Catheter ablation of idiopathic outflow tract ventricular arrhythmias with low intraprocedural burden guided by pace mapping

Background

There are limited data comparing ablation outcomes in patients with low intraprocedural burden of ventricular arrhythmias (VA) undergoing a pace mapping (PM)–guided strategy vs those with high burden guided by standard activation mapping strategy (non-PM).

Objective

We sought to determine if catheter ablation–guided by PM of low-intraprocedural-burden idiopathic outflow tract VA would be noninferior compared to non-PM-guided ablation.

Methods

Outcomes of catheter ablation of idiopathic outflow tract VA in 22 patients with a low burden of intraprocedural VA using PM-guided ablation were compared to 44 patients with a high burden of intraprocedural VA undergoing ablation using standard techniques.

Results

Sixty-six patients were included (age 46.5 ± 14.8 years; 68% female, left ventricular ejection fraction 59% ± 5%). Within the PM group, 24-hour preprocedure premature ventricular complex (PVC) burden was 9.5% (interquartile range [IQR] 4%–13.8%), number of pace maps 33.6 ± 18.5, surface area of ≥95% pace map correlation 1.9 ± 1.2 cm², with best pace map correlation 96% (IQR 92%–97%). Within the non-PM group, 24-hour preprocedure PVC burden was 13.5% (IQR 6.6%–30%), earliest activation time -33.7 ± 9.9 ms. Procedural duration, general anesthesia administration, fluoroscopy dose, and complications were all comparable. Following final procedure, 24-hour VA burden (PM 0% [IQR 0–2.4%] vs non-PM 0% [IQR 0–4.2%], P = .98), along with VA-free survival at 6-month follow-up (PM 77% vs non-PM 71%, P = .77), were both comparable.

Conclusion

In patients with low intraprocedural burden of outflow tract VA, PM-guided catheter ablation can accurately identify the VA site of origin, leading to outcomes comparable to those achieved with standard ablation techniques.

Impact of a predefined pacemapping protocol use for ablation of infrequent premature ventricular complexes: A prospective, multicenter study

BACKGROUND

Pacemapping (PM) is a useful maneuver for aiding premature ventricular complex (PVC) ablation. Its standalone clinical value is still to be defined.

OBJECTIVES

The purpose of this study was to analyze the efficacy of a predefined PM protocol for low-burden PVC ablation, regardless of their site of origin (SOO) and the presence of structural heart disease.

METHODS

This was a prospective, nonrandomized, multicenter study. The PM protocol was performed when <1 PVC/min was found. The "target area" was delimited by the 3 best matching points >94% correlation, and 3 radiofreqency (RF) applications were delivered.

RESULTS

Of 185 patients, 105 (57%) underwent activation mapping, 60 (32%) were PM-guided, and 20 (11%) were canceled due to absence of PVCs. Baseline QRS, PVC burden, and outflow tract origin were independent predictors of PM-guided ablation. A higher proportion of right ventricular outflow tract SOO in the PM group (52% vs 40%; P = .03) was observed. Mean target area was 0.6 ± 0.9 cm². Mean 10-ms isochronal area in local activation time (LAT)-guided procedures was higher (1.7 ± 2.3 cm²; P <.001). Mean number of PM matching points acquired was 39 ± 21 (range 6-98). Mean mapping and RF times were similar in both groups. However, significantly shorter procedural (53 ± 24 vs 61 ± 26 minutes; P = .04) as well as RF times (111 ± 51 vs 149 ± 149 seconds; P = .05) were needed in the PM group using the proposed protocol. Global clinical success reached 87% for the PM group and 90% (P = .58) the for LAT mapping group.

CONCLUSION

When LAT mapping is precluded, application of a PM-guided ablation protocol directed to >94% matching correlation target area is a more efficient alternative with comparable clinical results.

Mapping and Ablation of Arrhythmias from Uncommon Sites (Aortic Cusp, Pulmonary Artery, and Left Ventricular Summit)

Despite advances in our understanding of the relevant anatomy and mapping and catheter ablation techniques of idiopathic outflow tract ventricular arrhythmias, challenging sites for catheter ablation remain the aortic cusps, pulmonary artery, and notably the left ventricular summit. A systematic approach should be used to direct mapping efforts efficiently between endocardial, coronary venous, and epicardial sites. Foci at the left ventricular summit, particularly intraseptal and at the inaccessible epicardial region, remain difficult to reach and when percutaneous techniques fail, surgical ablation remains an option but with risk of late coronary artery stenosis.

Comparative spatial resolution of 12-lead electrocardiography and an automated algorithm

BACKGROUND

The spatial resolution of pacemapping using 12-lead electrocardiography (ECG) or PaSo software is unknown.

OBJECTIVE

The purpose of this study was to determine the spatial resolution of traditional ECG pacemapping and pacemapping using the PaSo coefficients.

METHODS

Seventeen patients undergoing ablation of supraventricular tachycardias or atrioventricular node were included. After ablation, chamber (right ventricular outflow tract/rest of the right ventricle/left ventricle) geometry was created with Carto 3. Pacingwas performed from any point in these cardiac regions, the QRS morphology being the template and the point being considered as arrhythmia "origin." Subsequently, pacing was performed from points around the "origin" (1538 points). The QRS of these tagged points were compared by traditional ECG pacemapping and PaSo coefficients. The spatial resolution was calculated using correlations between the distance away from the origin (measured by 3 computational methods) and traditional ECG pacemapping and PaSo coefficients, independently.

RESULTS

A 0.01-unit decrease in the PaSo coefficient resulted in 1.1 mm increased Cartesian distance (95% confidence interval [CI] 0.9-1.3 mm; P < .001) and 2.4 mm increased geodesic distance (95% CI 1.9-2.9 mm; P < .001) and 664 mm³ increase in convex hull volume (95% CI 423-906 mm³; P < .0001). For traditional ECG pacemapping, each decrease in lead match resulted in 1.7 mm increased Cartesian distance (95% CI 1.5-2.0 mm; P < .001) and 3.4 mm increased geodesic distance (95% CI 2.8-4.1 mm; P < .001) and 712 mm³ increase in convex hull volume (95% CI 599-830 mm³; P < .0001). Both PaSo coefficients and traditional pacemapping showed a significant inverse linear correlation with distance from the "origin."

CONCLUSION

The resolution of mapping using the Paso software is better than that of traditional pacemapping.