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Fasciculoventricular and atrioventricular accessory pathways in patients with Danon disease and preexcitation: A
Douglas Darden1, Jonathan C Hsu1, Wendy S Tzou2
1Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla, California.
Insights
Fasciculoventricular pathways (FVP) are common in Danon disease patients with preexcitation. Electrophysiological study (EPS) is recommended to identify these pathways and assess risks in patients with Danon disease.
Area of Science:
- Cardiology
- Genetics
- Electrophysiology
Background:
- Danon disease is a rare X-linked dominant genetic disorder causing hypertrophic cardiomyopathy.
- Fasciculoventricular pathway (FVP) is a suspected cause of preexcitation in Danon disease patients.
Purpose of the Study:
- To determine the prevalence of ventricular preexcitation in Danon disease patients using electrocardiogram (ECG).
- To analyze electrophysiological study (EPS) findings in Danon disease patients with preexcitation.
Main Methods:
- Retrospective analysis of a multicenter registry of Danon disease patients.
- Inclusion criteria: confirmed Danon disease with ECG-diagnosed preexcitation.
- Data collected: arrhythmias, implantable cardioverter-defibrillator (ICD) procedures, ICD shocks, and EPS results.
Main Results:
- Preexcitation found in 32.5% of 40 Danon disease patients.
- EPS in 9 patients revealed FVP or extranodal pathways in all.
- Two patients had malignant accessory pathway (AP) properties; 85% received ICDs.
Conclusions:
- High prevalence of FVP and extranodal pathways in Danon disease patients with preexcitation.
- EPS is crucial for assessing FVP and potential malignant AP in these patients.
- Early identification and management are vital for improving outcomes in Danon disease.
Background:
Studies have suggested that a fasciculoventricular pathway (FVP) may be the cause of preexcitation in patients with Danon disease, a rare X-linked dominant genetic disorder of hypertrophic cardiomyopathy.
Objective:
The purpose of this study was to describe the prevalence of ventricular preexcitation on resting 12-lead electrocardiogram (ECG) in patients with Danon disease and the electrophysiological study (EPS) results of those with preexcitation.
Methods:
Patients with confirmed Danon disease diagnosed with preexcitation (PR ≤120 ms, delta wave, QRS >110 ms) on ECG were included from a multicenter registry. The incidence of arrhythmias, implantable cardioverter-defibrillator (ICD) procedures, ICD shocks, and EPS results were collected.
Results:
Thirteen of 40 patients (32.5%) with Danon disease were found to have preexcitation (mean age 17.3 years; 38% women). EPS performed in 9 of 13 patients (69%) demonstrated FVP only in 2 (22.2%), extranodal pathway without exclusion of FVP in 2 (22.2%), and both FVP and extranodal pathway in 5 (55.6%). Two patients had malignant accessory pathway (AP) properties. Over median follow-up of 842 days (interquartile range 138-1678), 11 patients (85%) had ICD placement, and 6 (46.1%) underwent heart transplantation. No patients required therapy for ventricular tachycardia, and 2 patients (15%) had paroxysmal atrial fibrillation.
Conclusion:
In a large multicenter cohort of patients with Danon disease, there was a high prevalence of FVP and extranodal pathways diagnosed on EPS in those with preexcitation. These findings suggest patients with preexcitation and Danon disease should undergo EPS to assess for FVP and potentially malignant extranodal AP.
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