Unforeseen cardiac involvement in McArdle's disease

Area of Science:

• Biochemistry
• Genetics
• Cardiology

Background:

• McArdle's disease (glycogen storage disease type V) is a rare autosomal recessive metabolic myopathy.
• It results from myophosphorylase deficiency, primarily affecting skeletal muscle.
• Symptoms include exercise intolerance, muscle pain, and myoglobinuria, typically appearing in the second or third decade of life.

Observation:

• This report details an unusual case of a 33-year-old man with a known diagnosis of McArdle's disease.
• The patient presented with an incidental finding during a medical evaluation.
• The finding was severe obstructive hypertrophic cardiomyopathy.

Findings:

• Cardiac muscle involvement is exceptionally rare in McArdle's disease.
• This case presents a unique instance of significant cardiac pathology in a patient with this condition.
• The hypertrophic cardiomyopathy was obstructive in nature.

Implications:

• This case expands the understanding of potential McArdle's disease manifestations.
• It underscores the importance of considering cardiac evaluations even in rare presentations.
• Further research may elucidate the mechanisms linking McArdle's disease to cardiac complications.