Glycogen storage disease confined to the heart due to cardiac phosphorylase kinase deficiency causes a fatal infantile cardiomyopathy. Cardiomegaly can be detected in utero and is progressive. Electrocardiographic and echocardiographic findings are characteristic but not specific; these include large QRS complexes, short PR interval, and a hypertrophic nonobstructive pattern. Conclusive diagnosis requires biochemical analysis of myocardium, which may not be possible premortem due to the amount of tissue required. Pathologic examination of a standard cardiac biopsy can provide a presumptive diagnosis. There is no current treatment except a heart transplant. Infants succumb to heart failure and/or respiratory compromise due to pulmonary compression. This is a rare entity; only three cases have been reported to our knowledge. We report two additional cases.
- Glycogen storage disease type IX
- Infantile hypertrophic cardiomyopathy
- Phosphorylase kinase deficiency
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Pediatrics, Perinatology, and Child Health