Clinical significance of dipyridamole Tl-201 emission computed tomography perfusion abnormality for evaluating pathophysiological and pathological aspects in hypertrophic cardiomyopathy.
A dipyridamole-induced Tl-201 perfusion abnormality was evaluated from its clinical features, echocardiography and myocardial histopathology in 39 patients with hypertrophic cardiomyopathy (HCM). From the findings of Tl-201 emission computed tomography (ECT), subjects were divided into three groups: group 1 (n = 16) which did not show a perfusion abnormality in the hypertrophic region; group 2 (n = 12) which showed a perfusion defect on the initial image with complete redistribution on the delayed image; and group 3 (n = 11) which showed a persistent perfusion defect--this group included most patients who revealed partial and/or incomplete redistribution. Echocardiography revealed that group 2 showed a marked asymmetrical septal hypertrophy and an incidental obstructive pattern, and that group 3 had a significantly dilated left ventricular diastolic dimension and a decreased percentage of fractional shortening. Group 3 also showed frequent ventricular tachycardia and a familial history of cardiomyopathy. As for the myocardial biopsy findings, group 3 had significantly advanced myocardial fibrosis, the percentage being 6.0 +/- 3.1% in group 1; 5.5 +/- 2.5% in group 2; and 11.9 +/- 3.4% in group 3. Thus, it was concluded that the persistent perfusion defect on dipyridamole stress Tl-201 ECT testing is an important finding corresponding to the advanced clinical and pathological aspects of HCM.
Mori
T
T
First Department of Internal Medicine, Kobe University School of Medicine, Japan.
Yamabe
H
H
Yokota
Y
Y
Fukuzaki
H
H
D000328:Adult; D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D003326:Coronary Circulation; D004176:Dipyridamole; D004452:Echocardiography; D005260:Female; D006346:Heart Septum / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013794:Thallium Radioisotopes; D014055:Tomography, Emission-Computed
D013794:Thallium Radioisotopes; D004176:Dipyridamole