Spectrum of left ventricular dysfunction in potential pediatric heart transplant donors

Although myocardial dysfunction severe enough to preclude harvest for transplantation has been reported in approximately 20% of potential adult organ donors, the incidence of myocardial dysfunction in the pediatric population has not been studied systematically. Therefore, the purpose of this study was to determine the spectrum of myocardial dysfunction in potential pediatric heart transplant donors.

We reviewed the pediatric cardiology database at Primary Children's Medical Center to identify all children who had screening echocardiograms for potential organ donation. We reviewed charts for patient age and size, cause of brain death, and type of pharmacologic support. Echocardiograms were reviewed retrospectively for left ventricular systolic function (shortening or ejection fraction), wall motion abnormalities, diastolic function (mitral E/A ratio), Tei index, and mitral regurgitation.

We identified 23 potential donors (age, 6.7 +/- 4.4 years; range, 5 days to 15 years). All patients were receiving pharmacologic support. We found systolic left ventricular dysfunction, defined as an ejection fraction <50% or a shortening fraction <28%, in 57% (13/23) of the patients. We found mitral regurgitation in 85% (11/13) of the patients with systolic dysfunction and in zero of 10 with normal ejection phase indices. Diastolic dysfunction (mitral E/A reversal) was found in 45% (6/13) of those with systolic dysfunction and in 60% (6/10) of patients with normal systolic ejection phase indices. The Tei index was abnormal in 8 of 13 patients with left ventricular systolic dysfunction (range, 0.5-1.4), and was normal in the 6 patients with isolated diastolic dysfunction. One patient, who was electrocuted, had regional wall motion abnormalities. Of the 23 potential donors, 19 (87%) had evidence of systolic or diastolic dysfunction. A total of 13 hearts (3 with normal systolic function, 4 with systolic dysfunction, and 6 with isolated diastolic dysfunction) were harvested for transplantation.

Left ventricular systolic and diastolic dysfunctions are common findings in potential pediatric organ donors. Despite this, previous studies have shown that some of these hearts can be transplanted successfully. We speculate that some of the abnormalities occur as a physiologic consequence of brain death and, thus, may be reversible after transplantation. To avoid wasting a valuable, limited resource, further study is needed to identify the donors suitable for pediatric heart transplantation.