Cardiomyopathy Resulting From Primary Hyperoxaluria Type II
A 41-year-old man with right-sided dominant heart failure, dialysis-dependent renal insufficiency, and severe neuropathy of unknown cause was sent to our institution for cardiac examination. An echocardiogram showed reduced left ventricular systolic function and an echo-dense myocardium; therefore, amyloidosis was suspected. However, 2 rectal biopsies failed to show amyloid deposits.
Transthoracic echocardiography revealed a severely hypertrophied (interventricular septum, 17 mm; left ventricular posterior wall, 15 mm) and slightly dilated left ventricle with a moderately impaired ejection fraction (see the Movie at http://circ.ahajournals.org/cgi/content/full/113/3/e••/DC1). The right ventricle was also slightly hypertrophied and dilated; both atria were severely dilated. Severe tricuspid regurgitation was found, with an elevated systolic pulmonary artery pressure of 70 mm Hg. There was also a small pericardial effusion present. Doppler echocardiography was consistent with a restrictive filling pattern (Figure 1). Cardiac catheterization revealed markedly elevated left and right ventricular end-diastolic pressures (Figure 2); endomyocardial biopsy (Figure 3) established the diagnosis of oxalosis. Plasma oxalate levels were excessively increased (109 μmol/L; normal, 1 to 3 μmol/L). Immunoreactivity for glyoxylate reductase in a liver biopsy specimen was absent, and glyoxylate reductase activity was <5% of normal, establishing the diagnosis of primary hyperoxaluria type II.
Primary hyperoxaluria type II is a rare metabolic disease characterized by a deficiency of D-glycerate dehydrogenase, which leads to the accumulation of L-glycerate and oxalate in the body. This is, to the best of our knowledge, the first report of cardiomyopathy resulting from primary hyperoxaluria type II.
The Movie is a transthoracic apical 4-chamber view showing the echo-dense and granular sparkling structure of the left ventricular myocardium, especially in the interventricular septum and anterolateral papillary muscle. Left ventricular systolic function is moderately impaired (ejection fraction, 30%, biplane Simpson’s rule).
The online-only Data Supplement can be found at http://circ.ahajournals.org/cgi/content/full/113/3/e••/DC1.