title: Preclinical cardiac dysfunction in transfusion-dependent children and young adults detected with low-dose dobutamine stress echocardiography.
abstract: Transfusion-dependent (TD) patients develop cardiac iron overload that will eventually lead to cardiac pump failure. Low-dose dobutamine stress echocardiography may complement resting echocardiography and identify preclinical myocardial dysfunction caused by early cardiac hemosiderosis. Twenty-six iron-overloaded TD patients had stress echocardiography with 5 microg/kg per minute of dobutamine. Indexed left ventricular (LV) mass, LV dimensions, meridional wall stress, and cardiac index were significantly increased. TD patients had similar LV shortening fraction by M-mode (40.5% +/- 5.6% vs 39.4% +/- 4.5%) but had a lower mean LV ejection fraction (53.3% +/- 3.9% vs 46.8% +/- 6.9%, P < .002) and a subnormal increase in cardiac index during dobutamine stress (35% +/- 20% vs 11% +/- 16%, P < .0001). Impairment in LV relaxation was demonstrated by a prolonged isovolumetric relaxation time (0.060 +/- 0.005 vs 0.088 +/- 0.019 seconds, P < .0001), increased peak mitral E wave, and abnormal E/A ratio. Asymptomatic TD patients demonstrate decreased systolic functional reserve and abnormal left ventricular relaxation that may be caused by cardiac hemosiderosis. Low-dose dobutamine stress echocardiography may be useful for detecting and following cardiac dysfunction in patients at risk for cardiac hemosiderosis.
authors.affiliation: Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
authors.forename: W A
authors.initials: WA
authors.lastname: Suarez
authors.forename: S A
authors.initials: SA
authors.lastname: Snyder
authors.forename: B B
authors.initials: BB
authors.lastname: Berman
authors.forename: G M
authors.initials: GM
authors.lastname: Brittenham
authors.forename: C R
authors.initials: CR
authors.lastname: Patel
mesh_terms: D000293:Adolescent; D000328:Adult; D009202:Cardiomyopathies / Q000150:complications / Q000000981:diagnostic imaging*; D002316:Cardiotonic Agents; D002648:Child; D003971:Diastole; D004280:Dobutamine; D017707:Erythrocyte Transfusion; D005080:Exercise Test; D005260:Female; D006439:Hemodynamics; D006486:Hemosiderosis / Q000150:complications* / Q000209:etiology; D006801:Humans; D008297:Male; D013599:Systole; D014463:Ultrasonography; D018754:Ventricular Dysfunction / Q000150:complications / Q000000981:diagnostic imaging*
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine