Restrictive cardiomyopathy in a patient with primary hyperoxaluria type II

Abstract

This is the first report of a cardiac manifestation of a primary hyperoxaluria type II (PH II) with the hemodynamic characteristics of a severe restrictive cardiomyopathy. PH II is a rare inherited metabolic disease characterized by a deficiency of D-glycerate dehydrogenase, which has also glyoxylate reductase activity. This defect causes an accumulation of hydroxypyruvate the precursor of oxalate. The renal excretion of oxalate is impaired causing a deposition of oxalate mainly in the kidneys. To date, less than fifty cases have been reported. Systemic oxalosis in PH II is an occasional finding; thus far, myocardial oxalosis due to PH II has never been reported. Described is the case of a 41 year old male with renal failure and severe neuropathy of unknown cause, who underwent endomyocardial biopsy under the suspicion of cardiac amyloidosis. Echocardiography and cardiac catheterization showed a severe restrictive cardiomyopathy; endomyocardial biopsy established the diagnosis of oxalosis. Plasma oxalate levels were markedly increased, therefore a liver biopsy was performed. Immunoreactivity for D-glycerate dehydrogenase/ glyoxylate reductase was absent and activity of the enzyme was < 5% of normal. In summary, these findings established the diagnosis of a restrictive cardiomyopathy due to PH II.

Cardiac Abnormalities in Primary Hyperoxaluria

“…13,14,23 Case reports and limited case series describe some cardiac abnormalities such as increased wall thickness due to myocardial oxalate deposition. 5,6 restrictive cardiomyopathy, 24 heart failure, 6 tricuspid and mitral regurgitation. 4,6 conduction defeels, 4,25–29 ventricular tachycardia, 30 impaired LV and RV function.…”

Genetic Infiltrative Cardiomyopathies

“…The most common echocardiographic findings were increased left ventricular mass (29%) and left atrium enlargement (21%), and abnormal electrocardiogram findings included left ventricular hypertrophy (5%), bundle branch block (9%), and atrioventricular block (5%). 36 There have also been reports of PH patients presenting with ventricular tachycardia, 37 mitral valve regurgitation, 38 restrictive cardiomyopathy 39 and heart failure. 38 Combined liver and kidney transplantation has been shown to reverse cardiac dysfunction and oxalate deposits in the heart.…”

Infiltrative Cardiovascular Diseases

“…Myocardial oxalosis. Primary hyperoxaluria is a rare autosomal recessive disorder characterized by an enhanced production of oxalic acid, leading to the deposition of oxalate crystals in different organs, particularly the heart and the kidneys (48,49). Echocardiography demonstrates biventricular symmetrically thickened walls (49,50) (Fig.…”

“…4). Diastolic function is severely impaired, with elevated filling pressures and restrictive filling pattern (49,50). Patients usually present with complete atrioventricular block and ventricular conduction abnormalities correlating with diffuse extensive oxalate infiltration of the cardiac conduction system (50,51).…”