Clinical Electrophysiology -> SVT/AVNRT/WPW/AT: -> Epidemiology of Cardiac Arrhythmias/ Epidemiology D-AB27 - Arrhythmias, infiltration and hypertrophy (ID 27) Abstract

D-AB27-06 - High Prevalence Of Fasciculoventricular Pathways In Patients With Danon Disease And Pre-Excitation Pattern On ECG: A Multicenter Experience (ID 1468)


Background: Pre-excitation pattern on ECG has been described in Danon disease, a rare X-linked dominant genetic disorder of hypertrophic cardiomyopathy. A small study has suggested that a fasciculoventricular pathway (FVP) diagnosed by electrophysiology study (EPS) may be the cause of pre-excitation, but its prevalence in this population is unknown.
Objective: To describe the prevalence of FVPs and incidence of arrhythmias in patients with Danon disease and pre-excitation.
Methods: Patients with confirmed Danon disease diagnosed with pre-excitation (PR ≤ 120 ms and delta wave) on ECG were included from a multicenter registry. Incidence of arrhythmias, implantable cardiac defibrillator (ICD) procedures, ICD shocks, and EPS results were collected.
Results: Eleven patients (55% female, mean age 18.4 years) were included. ECG-based accessory pathway (AP) localization was right-sided in 9/11 (82%) and left-sided in 2/11 (18%). One patient with an ECG localized left-sided pathway had concomitant severe right ventricular hypertrophy on echocardiogram. Seven patients (64%) had ICD placement (2 for secondary prevention) and 4/11 (36%) underwent heart transplantation. No patients required therapy for VT, but two had inappropriate shocks over mean follow up 5.3 ± 2.8 years. Two patients had recurrent paroxysmal atrial fibrillation and 9/11 (82%) had evidence of non-sustained VT and SVT. EPS were performed in 6/11 (55%) patients with FVP confirmed in 5/6 (83%). One patient had focal atrial tachycardia ablation. Of the three patients who had an extranodal AP ablated (two with left posteroseptal AP and one with right posterolateral AP all with non-sustained induction of atrioventricular reentrant tachycardia), two had confirmed FVP while one may have mislabeled as enhanced AV nodal conduction.
Conclusion: In the largest cohort of patients with Danon disease and pre-excitation, there is a high prevalence of FVP diagnosed on EPS, which may even be an underestimate of the actual incidence. Despite the typically benign clinical course of FVP, further research into the clinical significance of APs in Danon disease is needed.