[Dobutamine echocardiography in children after heart transplantation].

Coronary disease of the transplanted heart is the principal cause limiting long-term survival of patients and grafts. In view of the invasive nature of coronary angiography, dobutamine echocardiography has been proposed as a non-invasive diagnostic method for this disease. The aim of this study was to determine the feasibility and reliability of this investigation in transplanted children. Twenty-one echoes were performed with dobutamine infusions in 17 patients transplanted at 10 months to 16.9 years of age (average 8.4 years), and followed up 1.1 to 10.1 years (average 4.4 years): 4 were on antihypertensive drugs but none were treated by betablockers. Dobutamine echocardiography was performed according to the standard protocol used in adults. The maximal level was attained in all cases. No major side effects were observed. The maximal heart rate attained 57 to 89% of the theoretical maximal rate, an increase of 44 to 184% compared with the basal heart rate. The maximal systolic blood pressure rose to 120 to 194 mmHg, an increase of 8 to 109% compared with resting values. The contractility scores and segmental contractile index were normal in 18 cases, abnormal at the maximal level in 2 cases (hypokinesia of segments 8 and 9 and akinesia of segments 10 and 16 with an index of 1.2), abnormal at the lowest levels (hypokinesia of segment 7 with an index of 1.1) and maximal level (hypokinesia of segments 1 and 7 with an index of 1.2) in one case. These results were concordant with coronary angiography performed within 2 to 8 days of echocardiography, and considered as the diagnostic investigation of reference (sensitivity 75%, specificity 100%, positive predictive value 100% and negative predictive value 93%). The authors conclude that dobutamine echocardiography is a non-invasive method easily performed with low risk in transplanted children but its diagnostic performance in coronary disease of the transplanted heart should be confirmed in larger studies.