Evidence of evolution towards left midventricular obstruction in severe Anderson-Fabry cardiomyopathy

Area of Science:

• Cardiology
• Genetics
• Rare Diseases

Background:

• Fabry cardiomyopathy is a genetic disorder causing progressive cardiac damage.
• Left ventricular outflow tract obstruction is a rare complication, often mimicking hypertrophic cardiomyopathy.
• Severe left ventricular hypertrophy (LVH) is a hallmark of advanced Fabry cardiomyopathy.

Purpose of the Study:

• To investigate the evolution of cardiac phenotype in Fabry disease patients.
• To identify specific patterns of LVH leading to left ventricular outflow tract obstruction.
• To describe a newly observed midventricular obstructive form of Fabry cardiomyopathy.

Main Methods:

• Case series of three classically affected male patients with Fabry disease.
• Analysis of cardiac imaging to assess left ventricular hypertrophy (LVH) and obstruction.
• Evaluation of disease progression despite enzyme replacement therapy.

Main Results:

• All patients developed a midventricular obstructive phenotype over time.
• Massive LVH involving papillary muscles was the primary cause of obstruction.
• This obstruction pattern differed from typical hypertrophic cardiomyopathy.

Conclusions:

• Fabry cardiomyopathy can evolve into a midventricular obstructive form.
• This progression is linked to significant diagnostic delay and severe LVH prior to treatment.
• The midventricular obstructive phenotype may represent an adverse outcome of Fabry disease.