Left ventricular pannus causing inflow obstruction late after mitral valve replacement for endocardial fibroelastosis

Area of Science:

• Cardiology
• Pediatric Cardiology
• Cardiac Surgery

Background:

• Endocardial fibroelastosis (EFE) is a rare congenital heart disease characterized by excessive fibrous and elastic tissue in the endocardium.
• Mitral valve replacement is a treatment option for severe mitral valve disease, including that caused by EFE.
• Complications after prosthetic valve implantation can occur, necessitating careful long-term monitoring.

Observation:

• A 14-year-old boy with a history of EFE and prior mitral valve replacement presented with cardiac failure.
• Echocardiography revealed a thickened, immobile prosthetic valve causing restrictive left ventricular inflow and severely reduced ejection fraction.
• Electrocardiogram showed atrioventricular reentry tachycardia, and the patient ultimately experienced cardiac arrest and died.

Findings:

• Postmortem examination identified severe left ventricular inflow obstruction.
• This obstruction was attributed to pannus/fibrosis formation around the prosthetic mitral valve's ventricular aspect.
• This specific complication of pannus formation after mitral valve replacement in pediatric EFE has not been previously described.

Implications:

• This case highlights a novel and potentially fatal complication following mitral valve replacement in pediatric patients with EFE.
• It underscores the importance of recognizing and investigating prosthetic valve dysfunction in this patient population.
• Further research may be needed to understand the mechanisms and optimize management strategies for EFE-related valve complications.