[Dissection of the accessory conduction pathways with simultaneous mitral valve surgery].

Area of Science:

• Cardiology
• Cardiac Surgery
• Electrophysiology

Background:

• A 44-year-old female presented with severe heart failure and hypotonia due to rapid ventricular rates from double atrioventricular accessory pathways during atrial fibrillation, exacerbated by mitral stenosis.
• Medical management with antiarrhythmics (prajmaline, propafenone, digoxin) initially slowed ventricular rates but did not fully resolve symptoms.
• Echocardiography and hemodynamic evaluation confirmed mitral stenosis (orifice 75 mm2) with moderate regurgitation, and minor aortic and tricuspid regurgitation.

Observation:

• Initial medical management involved antiarrhythmic drugs (prajmaline and propafenone) to block accessory pathway conduction, followed by digoxin to further slow ventricular rate, achieving rates of 80-100 bpm without pre-excitation.
• ECG analysis during atrial fibrillation localized the accessory pathways to the lateral and posterior left free wall.
• Diuretics and vasodilators were continued to manage heart failure symptoms.

Findings:

• Surgical intervention included dissection of both atrioventricular bypass tracts using Sealy's method (Cox modification) and implantation of a Medtronic-Hall 27 mm mitral valve prosthesis.
• Post-operatively, antiarrhythmic medications were discontinued, and pre-excitation did not recur.
• Successful electroversion restored sinus rhythm, and the patient was discharged without overt heart failure.

Implications:

• This case highlights the efficacy of a combined surgical and medical strategy for managing complex cardiac conditions involving accessory pathways and valvular heart disease.
• The successful treatment underscores the importance of accurate pathway localization and tailored therapeutic approaches for patients with refractory heart failure.
• The long-term absence of pre-excitation post-surgery suggests a durable solution for this challenging clinical presentation.