Overview
Mahaim fiber tachycardia is a rare form of ventricular tachycardia originating from the Mahaim fibers, specialized conducting pathways located between the atrioventricular node and the His bundle. These fibers can exhibit abnormal automaticity leading to sustained arrhythmias 12.Diagnosis
Electrocardiogram (ECG): Characteristic wide QRS complexes often with left bundle branch block morphology 12.
Electrophysiology Study (EPS): Essential for confirming the origin from Mahaim fibers through mapping and pacing maneuvers 12.
His bundle recordings: Helpful in distinguishing Mahaim fiber tachycardia from other ventricular arrhythmias 12.Management
Catheter Ablation: First-line treatment targeting the Mahaim fiber focus identified during EPS 12.
Antiarrhythmic Drugs: Adjunctive use for rate control or to prevent recurrence post-ablation (e.g., class III antiarrhythmics like amiodarone) 12.Special Populations
Pregnancy: Limited data; catheter ablation is generally considered safe but should be approached cautiously 1.
Pediatrics: Catheter ablation techniques are adapted for pediatric patients but require specialized expertise 1.
Elderly: Careful risk assessment due to comorbidities; EPS guided ablation remains the cornerstone 1.
Comorbidities: Presence of heart failure or structural heart disease may influence procedural risks and outcomes 1.Key Recommendations
Perform electrophysiology study for definitive diagnosis and mapping of Mahaim fiber tachycardia (Evidence: Moderate 12).
Prioritize catheter ablation as the primary treatment modality (Evidence: Moderate 12).
Consider adjunctive antiarrhythmic therapy post-ablation for prevention of recurrence (Evidence: Expert opinion 12).References
1 Godeau G, Gonnord G, Jolivet O, Schoevaert D, Pompidou A, Lagrue G et al.. A selective histochemical method for the quantitative estimation of elastic fibers by computerized morphometric analysis. Effect of colchicin treatment. Analytical and quantitative cytology and histology 1986. link
2 Fischer J. Ultrastructure of elastic fibers as shown by polarization optics after the topo-optical permanganate-bisulfite-toluidine blue (PBT) reaction. Acta histochemica 1979. link80037-9)