Electroanatomic Mapping of Endocardial Right Ventricular Activation as a Guide for Catheter Ablation in Patients with Arrhythmogenic Right Ventricular Dysplasia

Abstract

Arrhythmogenic right ventricular dysplasia is a structural heart disease characterized by fibrofatty degeneration of right ventricular myocardium and arrhythmias of right ventricular origin. The aim of this study was to characterize endocardial right ventricular activation by electroanatomic mapping as a guide for catheter ablation in patients with arrhythmogenic right ventricular dysplasia. Electroanatomic mapping and entrainment procedures were performed in 5 patients with arrhythmogenic right ventricular dysplasia. Endocardial mapping during ventricular tachycardia demonstrated a focal activation pattern with radial spreading of activation from a site of earliest ventricular activation in all directions. Right ventricular activation time (127 +/- 34 ms) was markedly shorter than tachycardia cycle length (415 +/- 92 ms). The site of earliest ventricular activation was found in an aneurysmal outflow tract (n = 2), at the border of aneurysms near the tricuspid annulus (n = 2), and at the apex of the right ventricle (n = 1). Entrainment mapping criteria of these areas of earliest endocardial activity were consistent with exit sites of a reentrant circuit in an area of abnormal myocardium. Fractionated potentials were found 61 +/- 29 ms before the onset of the QRS complex at these sites. Catheter ablation rendered the "clinical" ventricular tachycardia noninducible in four patients but "nonclinical" faster ventricular tachycardias were inducible in three patients. During the follow-up of 7 +/- 3 months after ablation, the frequency of therapies in 4 patients with an implantable cardioverter defibrillator decreased from 49 +/- 61 episodes per month before ablation, to 0.3 +/- 0.5 episodes per month after ablation (P < 0.05). Electroanatomic mapping during ventricular tachycardia facilitates localization of exit sites in relation to aneurysms in diseased right ventricle and may guide catheter ablation in patients with arrhythmogenic right ventricular dysplasia.

Short- and Long-Term Success of Substrate-Based Mapping and Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Dysplasia

“…This has also been the experience of other investigators. 2,3,6 One reason is that ARVD is a progressive disease, with new regions of scar developing over time and creating new circuits or changes in current ones. 20 Another explanation is that because ARVD may create a large number of potential circuits, an empiric approach may not eliminate all of the possible pathways.…”

“…1 In ARVD, fibrofatty replacement of myocardium produces "islands" of scar region that may lead to reentrant ventricular tachycardias (VTs), and patients have an increased risk of sudden cardiac death, mostly secondary to VT. [1][2][3] The use of implantable cardioverter/defibrillators (ICDs) is the treatment of choice for many ARVD patients with VT. 2,4,5 However, VT ablation may be indicated for some patients either as a primary therapy or as an adjunct to ICD implantation. 3,6 Although successful VT ablation is feasible in ARVD patients, long-term recurrence is common, probably because of the progressive nature of the disease. 2 Furthermore, multiple morphologies, hemodynamic instability, or noninducibility may limit the success of VT ablation.…”

Right ventricular dysplasia: management and treatment in light of current evidence

“…RFA is not a definitive therapy for patients with ARVC [31,46]. However, RFA can be considered as an adjuvant therapy to ICD placement in patients with VT or frequent ICD firing despite using BB or antiarrhythmic drugs or in patients who were not able to tolerate ARVC recommended medications (class I) [22].…”

“…However, RFA can be considered as an adjuvant therapy to ICD placement in patients with VT or frequent ICD firing despite using BB or antiarrhythmic drugs or in patients who were not able to tolerate ARVC recommended medications (class I) [22]. Furthermore, multiple electrophysiologic mapping techniques have been used to treat VA including voltage mapping and substrate mapping [31,32,46–48]. …”

Ventricular tachycardia mapping and ablation in arrhythmogenic right ventricular cardiomyopathy/dysplasia: Lessons Learned

“…This is likely the result of a number of different mapping and ablation strategies with variable endpoints, follow-up assessment, and operator experience [8][9][10][11][12][13] . In our experience at the University of Pennsylvania, a comprehensive ablation strategy that targets both the endocardial and epicardial substrate with elimination of abnormal electrograms and all inducible VT provides long-term drug-free arrhythmia control in a large majority of patients.…”