Conduction velocity is reduced in the posterior wall of hypertrophic cardiomyopathy patients with normal bipolar voltage undergoing ablation for paroxysmal atrial fibrillation

• Published in: Journal of interventional cardiac electrophysiology Vol. 67; no. 1; pp. 203 - 210
• Main Authors: Zahid, Sohail, Malik, Tahir, Peterson, Connor, Tarabanis, Constantine, Dai, Matthew, Katz, Moshe, Bernstein, Scott A., Barbhaiya, Chirag, Park, David S., Knotts, Robert J., Holmes, Douglas S., Kushnir, Alexander, Aizer, Anthony, Chinitz, Larry A., Jankelson, Lior
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-01-2024; Springer Nature B.V
• Subjects: Ablation; Arrhythmia; Atria; Atrial Appendage - surgery; Atrial Fibrillation - diagnostic imaging; Atrial Fibrillation - etiology; Atrial Fibrillation - surgery; Cardiac arrhythmia; Cardiology; Cardiomyopathy; Cardiomyopathy, Hypertrophic - complications; Cardiomyopathy, Hypertrophic - diagnostic imaging; Cardiomyopathy, Hypertrophic - surgery; Catheter Ablation - adverse effects; Catheters; Conduction; Disease control; Electric potential; Fibrillation; Heart Atria - diagnostic imaging; Heart Atria - surgery; Humans; Medical instruments; Medicine; Medicine & Public Health; Radio frequency; Radiofrequency ablation; Review; Statistical analysis; Velocity; Voltage; Hypertrophic cardiomyopathy; Cardiac electrophysiology; Biomedical engineering
• ISSN: 1572-8595; 1383-875X; 1572-8595
• DOI: 10.1007/s10840-023-01533-9

Objectives
We investigated characteristics of left atrial conduction in patients with HCM, paroxysmal AF and normal bipolar voltage.
Background
Patients with hypertrophic cardiomyopathy (HCM) exhibit abnormal cardiac tissue arrangement. The incidence of atrial fibrillation (AF) is increased fourfold in patients with HCM and confers a fourfold increased risk of death. Catheter ablation is less effective in HCM, with twofold increased risk of AF recurrence. The mechanisms of AF perpetuation in HCM are poorly understood.
Methods
We analyzed 20 patients with HCM and 20 controls presenting for radiofrequency ablation of paroxysmal AF normal left atrial voltage(> 0.5 mV). Intracardiac electrograms were extracted from the CARTO mapping system and analyzed using Matlab/Python code interfacing with Core OpenEP software. Conduction velocity maps were calculated using local activation time gradients.
Results
There were no differences in baseline demographics, atrial size, or valvular disease between HCM and control patients. Patients with HCM had significantly reduced atrial conduction velocity compared to controls (0.44 ± 0.17 vs 0.56 ± 0.10 m/s,
p
 = 0.01), despite no significant differences in bipolar voltage amplitude (1.23 ± 0.38 vs 1.20 ± 0.41 mV,
p
 = 0.76). There was a statistically significant reduction in conduction velocity in the posterior left atrium in HCM patients relative to controls (0.43 ± 0.18 vs 0.58 ± 0.10 m/s,
p
 = 0.003), but not in the anterior left atrium (0.46 ± 0.17 vs 0.55 ± 0.10 m/s,
p
 = 0.05). There was a significant association between conduction velocity and interventricular septal thickness (slope = -0.013, R
2
 = 0.13,
p
 = 0.03).
Conclusions
Atrial conduction velocity is significantly reduced in patients with HCM and paroxysmal AF, possibly contributing to arrhythmia persistence after catheter ablation.