Abnormal patterns of noninvasively reconstructed epicardial signals and right ventricle activations in patients with Arrhythmogenic Right Ventricular Cardiomyopathy and gene-carriers
Authors: Kommata B , Sciaraffia E , Blomstrom- Lundqvist C 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Selanders stiftelsen

Background
ARVC primarily affects the epicardium resulting in electrical abnormalities and ventricular arrhythmias that can appear before its clinical correlate with structural changes, which is often hard to evaluate non-invasively.

Purpose
To evaluate whether a 252-leads Body Surface Mapping (BSM) system can reveal RV activation abnormalities by non-invasively reconstructed epicardial signals of the right ventricle (RV) in ARVC patients and non-affected gene-carriers (GC).

Methods
Twelve ARVC patients, 20 GC and 8 genotype-negative family members serving as controls (C) underwent 12-leads ECG, signal-average ECG, echocardiography and 10 minutes recording with a non-invasive 252-leads BSM System. A thoracic CT scan was required for the construction of anatomically adapted epicardial signals. The reconstructed epicardial signals were studied using the Activation Time Editing tool of the BSM system. The morphologies of QRS complexes and T waves in predefined areas, including anterior free wall (AW), apex, RV base, RV inferior wall (IW) and RVOT, were studied. The pattern of RV activation was also studied.

Results
In controls the QRS morphology showed a rS pattern in most RV regions except for in the RVOT showing a rSr’ pattern and the IW where the signals had either a rS or rSr’ morphology. The T waves were positive in all areas, except for in the RV basis and in the IW, where 6 and 3 controls, respectively, had negative/isoelectric T waves. The earliest activation of the RV occurred in the anterior paraseptal region in 7/8 C, while the latest activation occurred in RVOT in 7/8 C (figure 1).
ARVC patients also more commonly had a rS pattern in all regions except for in the RVOT (rSr’ pattern) and IW (rS or rSr’ pattern), but had a higher variation in the QRS morphology. Fractionated signals were seen in 7/12 cases. The epicardial T waves were negative/ isoelectric in 11/12 cases. Even though the RV activation more commonly started in the anterior paraseptal region and ended at the RVOT, 58% of ARVC patients had different areas of earliest and/or latest activation (figure 1).
GC had the same distribution of QRS morphology as in C, but up to 75% of the T waves were negative or isoelectric, particularly in the RV base and IW. Fractionated signals were seen in two cases. In 60% of GC the earliest and/or latest activation location differed from those see in C.

Conclusions
Using the 252-leads BSM system, distinct characteristics of reconstructed epicardial signals and RV activation patterns were detected in ARVC patients, distinguishing them from C. The observation that similar changes were observed in epicardial signals and activation patterns among GC suggest that the 252-leads BSM system may be useful as a non-invasive tool evaluating genetically predisposed subjects for early manifestations of the disease.