| Dobutamine stress echocardiography for children with acquired and congenital cardiac diseases | |
Abstract/OtherAbstract
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(Uncorrected OCR) Abstract of thesis entitled Dobutamine Stress Echocardiography for Children with Acquired and Congenital Cardiac Diseases Submitted by Ling Hui for the degree of Doctor of Philosophy at the University of Hong Kong in December 2003 Dobutamine stress echocardiography was proven to be a sensitive, accurate and non-invasive diagnostic technique for detecting cardiac dysfunction in adults with coronary artery disease. The relationship of left ventricular (LV) meridonal wall stress and rate-corrected velocity of circumferential fibre shortening was described as a load-independent index of myocardial contractility (stress-velocity index). This study combined dobutamine stress echocardiography with a number of echocardiographic indices, including the stress-velocity index, for possible early detection of myocardial dysfunction in two groups of children, those with congenital heart diseases and those with acquired diseases. For congenital heart diseases, two major groups with potential coronary arterial involvement, namely transposition of the great arteries (TGA) after arterial switch operation and coronary arterial fistula (CAF) after interventions were studied. Since the coronary arteries supply the myocardium, it is anticipated that the LV function and wall motion may be affected if the coronary arteries are affected intra-operatively or post-operatively. For acquired heart disease, patients with Kawasaki� disease (KD) who have persistent coronary arterial aneurysm were included as they have coronary abnormalities. In addition, patients with �thalassemia major were included as they might have iron overload by repeated transfusions, resulting in damage to the myocardium. The above four sub-groups of patients comprised the sample for the study. The LV systolic indices and wall motion scores were detected at rest and under stress in the patients and compared with normal controls. Those patients had their wall motion abnormalities correlated with the findings of thallium scan. For TGA patients after operation (n=31), the LV indices were significantly lower than normal controls both resting and stressed. Using the stress-velocity index, abnormal myocardial contractility was found in 19 of 31 patients at rest. Under stress, an additional six patients were found to have abnormal myocardial contractility, but only one patient had wall motion abnormality. For CAF patients (n=9), resting indices were not significantly different between the patients and controls. The stressed indices were all significantly lower in the patients. At rest, the stress-velocity index was normal for all patients. When stressed, this was significantly lower in two patients. The �thalassemia patients (n=26) were divided into two subsets under stress using the stress-velocity index: 11 patients were found to be in the "abnormal" subset under stress, while only three were in the abnormal subset at rest. Two years later, at follow up, using the same measures, all patients in the "abnormal" subset under stress, were ranked in the abnormal subset at rest. For KD patients (n=22), their LV indices were significantly lower than normal controls at rest. Sixteen patients having abnormal wall motion had impaired perfusion defects proved by thallium scan, the areas of wall motion abnormalities correlated well with the findings of thallium scan. As a conclusion, dobutamine stress echocardiography can be safely applied to children and can early detect wall motion abnormalities. Additionally, this technique can early identify those subsets of patients with LV myocardial dysfunction in both congenital and acquired cardiac diseases in children. |
Authors
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Hui, Ling, 許凌 |
Contributors
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Publication Detail
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Publisher : University of Hong Kong (Pokfulam Road, Hong Kong) Type : Electronic Thesis & Dissertation Format : application/pdf, 122 leaves : ill. (some col.) ; 30 cm. |
Date Detail
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2004 |
Subject
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Dobutamine - Diagnostic use., Echocardiography., Coronary heart disease in children - Diagnosis. |
Coverage
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Relation
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Source
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http://sunzi.lib.hku.hk/hkuto/record/B29914954 |
Copyright Information
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unrestricted, The author retains all proprietary rights, (such as patent rights) and the right to use in future works. |
Other Details
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Languages : eng |
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