Biventricular hypoplasia with myocardial fiber hypertrophy and disarray

Area of Science:

• Cardiology
• Pathology
• Developmental Biology

Background:

• Investigating rare congenital heart conditions.
• Understanding the impact of severe atrioventricular valve regurgitation on ventricular development.
• Examining the histological features of congenital cardiomyopathies.

Observation:

• A 25-year-old woman presented with lifelong effort intolerance and systemic venous congestion.
• Cardiac catheterization revealed restrictive ventricular filling and severe atrioventricular (A-V) valve regurgitation.
• The patient died post-valve replacement surgery.

Findings:

• Autopsy showed enlarged, thickened atria and small ventricles.
• Myofibers in both ventricles were hypertrophied.
• Widespread fiber disarray was noted in the left ventricle, interventricular septum, and focally in the right ventricle.
• The ventricles were not enlarged or thickened, a finding inconsistent with chronic severe A-V regurgitation.

Implications:

• This case represents a rare instance of biventricular hypoplasia and dysplasia.
• The findings challenge typical understandings of ventricular remodeling in response to chronic volume overload.
• Further research into the genetic and developmental mechanisms underlying such conditions is warranted.