Dobutamine stress echocardiography: experience in pediatric heart transplant recipients.
BACKGROUND
Transplant coronary arteriopathy causes late death and is difficult to detect noninvasively. Dobutamine stress echocardiography is being used for risk stratification in adult recipients at some transplant centers, thus we investigated its role in a pediatric population.


METHODS
We performed 46 stress echo studies (mean age = 11.8 years; mean years post transplantation = 4.3). An atropine/dobutamine protocol (5-40 mcg/kg/min) was used to attain a predicted target heart rate. Serial echocardiographic images were acquired at baseline and at each increment of dobutamine and recovery, and were digitized online. Data were correlated with endomyocardial biopsy (n = 23), coronary angiography (n = 26) or autopsy (n = 6). All studies were well tolerated.


RESULTS
Target heart rate was achieved in 41/46 (89%) studies. The mean heart rate significantly increased from 95 to 169 beats/min and mean systolic blood pressure from 123 to 153 mm Hg (p<.05). The mean peak pressure-rate product was 23,041 beats-mm Hg/min. Coronary arteriopathy was confirmed in 5 patients by angiography (n = 3) explanted heart (n = 1) or autopsy (n = 4). In this group, abnormalities included a new reversible wall motion abnormality (n = 2), left ventricular cavity dilation with stress (n = 3), ischemia (n = 2), increased mitral insufficiency (n = 1) and marked diastolic dysfunction (n = 1). A positive study predicted death or graft failure (p< .0005).


CONCLUSIONS
Echocardiographic abnormalities during stress correlated with coronary arteriopathy in this small cohort of patients; however, larger multi-center studies are warranted to assess the utility of dobutamine stress echocardiography for risk stratification for coronary disease in pediatric transplant recipients.
Pahl
E
E
Heart Transplantation, The Children's Memorial Hospital, Chicago, Illinois 60614, USA.
Crawford
S E
SE
Swenson
J M
JM
Duffy
C E
CE
Fricker
F J
FJ
Backer
C L
CL
Mavroudis
C
C
Chaudhry
F A
FA
D000293:Adolescent; D001706:Biopsy; D002316:Cardiotonic Agents; D016009:Chi-Square Distribution; D002648:Child; D015331:Cohort Studies; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis; D004280:Dobutamine; D004452:Echocardiography / Q000379:methods* / Q000706:statistics & numerical data; D005080:Exercise Test / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D016027:Heart Transplantation / Q000000981:diagnostic imaging* / Q000473:pathology / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D009206:Myocardium / Q000473:pathology; D015588:Observer Variation; D012189:Retrospective Studies
D002316:Cardiotonic Agents; D004280:Dobutamine