Assessment of wave front activation duration and speed across the right ventricular outflow tract using electrocardiographic imaging as predictors of the origin of the premature ventricular contractions: A validation study

Enhancing premature ventricular contraction localization through electrocardiographic imaging and cardiac digital twins

Premature ventricular contractions (PVCs) represent a common and clinically significant cardiac arrhythmia, contributing to a spectrum of cardiovascular disorders. Accurate localization of the origin of PVCs is essential for devising targeted therapeutic strategies and refining our comprehension of ventricular arrhythmogenesis. Traditionally, the 12-lead ECG has been the go-to diagnostic tool for PVCs. However, individual anatomical differences and inter-patient electrophysiology variability limit its effectiveness. This study presents a new method that combines electrocardiographic imaging (ECGI) with the concept of cardiac digital twins (ECGI-DT) to improve the accuracy of pinpointing the source of PVCs. By simulating a database of PVCs, we developed an ECGI-DT capable of estimating the origins of PVCs with much greater precision than possible previously. This study shows a notable improvement in identifying the initial site of PVC origin using ECGI-DT compared to ECGI alone: the average localization error dropped from 30.69 ± 23.71 mm with standard ECGI to 7.81 ± 3.82 mm using the ECGI-DT method. This marked reduction in error highlights the potential of ECGI-DT in revolutionizing PVC diagnosis and treatment. With its ability to provide more accurate and reliable data, ECGI-DT could improve the planning of catheter ablation treatments, a preferred intervention for managing PVCs that face challenges such as high costs and in some cases long procedure times.

Electrocardiographic imaging to guide ablation of ventricular arrhythmias and agreement between two different systems

BACKGROUND AND AIM

A recent study using an epicardial-only electrocardiographic imaging (ECGI), suggests that the agreement of ECGI activation mapping and that of the contact mapping for ventricular arrhythmias (VA) is poor. The aim of this study was to assess the diagnostic value of two endo-epicardial ECGI systems using different cardiac sources and the agreement between them.

METHODS

We performed 69 ECGI procedures in 52 patients referred for ablation of VA at our center. One system based on the extracellular potentials was used in 26 patients, the other based on the equivalent double layer model in 9, and both in 17 patients. The first uses up to 224 leads and the second just the 12‑lead ECG. The localization of the VA was done using a segmental model of the ventricles. A perfect match (PM) was defined as a predicted location within the same anatomic segment, whereas a near match (NM) as a predicted location within the same segment or a contiguous one.

RESULTS

44 patients underwent ablation, corresponding to 58 ECGI procedures (37 with the first and 21 with the second system). The percentage of PMs and NMs was not significantly different between the two systems, respectively 76% and 95%, p = 0.077, and 97% and 100%, p = 1.000. In 14 patients that underwent ablation and had the ECGI performed with both systems, raw agreement for PMs was 79%, p = 0.250 for disagreement.

CONCLUSIONS

ECGI systems were useful to identify the origin of the VAs, and the results were reproducible regardless the cardiac source.

A simplified approach to radiofrequency catheter ablation of idiopathic ventricular outflow tract premature ventricular contractions

BACKGROUND

Frequently, low voltage areas (LVAs) and diastolic potentials (DPs) are present at ablation site in sinus rhythm in patients with idiopathic premature ventricular contractions (PVCs).

OBJECTIVE

Validate these findings as substrate for PVCs and evaluate the feasibility of a simplified substrate approach based on LVAs and DPs for ablation of idiopathic outflow tract PVCs, in patients with a low PVC burden during the procedure.

METHODS

Prospective single-arm clinical trial at two centers with comparison with a historical group, matched to age and gender. The study group consisted of consecutive patients referred for ablation of frequent idiopathic PVCs with inferior axis, that presented with less than 2 PVCs/min in first 5 minutes of the procedure. The ablation was based on fast mapping of the RVOT in sinus rhythm looking for LVAs and DPs, defined as isolated small amplitude potentials occurring after the T wave of the surface ECG. The area with LVAs and DPs was tagged, and a simplified activation mapping of the PVCs was done in that area. The procedure time, success rate and recurrence rate were compared with the historical group in whom ablation was performed based on activation and pace mapping only. A validation group without PVCs was also studied to assess the prevalence of LVAs and DPs in the general population.

RESULTS

The study (n=38), historical (n=38) and validation (n=38) groups did not differ in relation to age or gender. Prevalence of LVAs and DPs was significantly higher in the study group in comparison with the validation group, respectively, 71% vs 11%, p<0.0001 and 87% vs 8%, p<0.0001. Procedure time was significantly lower in the study group when comparing to the historical group, 130 (100-164) vs 183 (160-203) min, p<0.0001 and the success rate was significantly higher, 90% vs 64%, p=0.013. The recurrence rate in patients with a successful ablation was not significantly different between both groups, Log-Rank=0.125.

CONCLUSION

Prevalence of LVAs and DPs was significantly higher in the study group than in the validation group. The proposed approach proved to be feasible, faster and more efficient than the historical approach. This article is protected by copyright. All rights reserved.