Apical sparing of longitudinal strain, left ventricular rotational abnormalities, and short-axis dysfunction in primary hyperoxaluria type 1.

A 24-year-old woman with end-stage renal failure because of primary hyperoxaluria type 1 was evaluated in our hospital for systemic calcium oxalate deposition in the course of long-term (5 years) hemodialysis therapy. Diagnosis of primary hyp-eroxaluria type 1, a hereditary cause of calcium oxalate kidney stones or progressive nephrocalcinosis that frequently results in end-stage renal failure, 1 was made by liver biopsy (reduced alanine:glyoxylate aminotransferase activity, 3.0 µmol/h per milligram protein; normal, 19.1–47.9) and by genetic testing (homozygosity for the c.302 T>C, AGXT mutation). Her plasma oxalate level on regular hemodialysis (3× per week over 4 hours) was increased (86 µmol/L predialysis; normal, <10 µmol/L). Transthoracic echocardiography revealed increased wall thickness of the left ventricle (LV; Figure 1). The LV was mildly dilated and showed a decreased systolic function. Flow across the mitral valve demonstrated a restrictive filling pattern. Moreover, the myocardium had a characteristic echo-dense granular sparkling appearance (Movie in the online-only Data Supplement). 2 Both atria were enlarged. Moderate tricuspid regurgitation was present. A right ventricle systolic pressure of 62 mm Hg was calculated. We used 2-dimensional speckle tracking echocardiography to assess the multidirectional myocardial function. Global LV longitudinal peak systolic strain (LS) was impaired (−13.5%; normal, −20.9±1.3%). 3 LS was severely reduced in the basal and midventricular segments of the lateral and septal LV walls. Moreover, LS in the apical segments was relatively preserved resulting in a typical apical sparing strain pattern (Figure 2). Short-axis myocardial function was also affected (Figure 3), and reversed LV rotation at the basal level with loss of LV twist mechanics was noted, suggesting impairment of both systolic and diastolic myocardial LV function (Figure 4). Currently, the patient experiences increasing oxalate osteopathy and heart failure. We, hence, recommended to increase the hemodialysis regimen to 6×3−4 hours/week to achieve a maximal oxalate removal. However, no form of dialysis will sufficiently remove the body oxalate stores and hence, she would urgently need combined or sequential liver–kidney transplantation. Discussion This report highlights the adjunctive role of 2-dimensional speckle tracking echocardiography in metabolic conditions such as primary hyperoxaluria type 1. Although typical characteristics of infiltrative cardiomyopathy with restrictive physiology were easily recognized using conventional echocardiography in our patient, 2-dimensional speckle tracking echocardiogra-phy identified important additional echocardiographic features, which may increase our understanding of the mechanisms contributing to cardiac dysfunction in systemic oxalosis. Apical sparing is a pattern of regional differences in deformation , in which LS …