Utility of various radionuclide techniques for distinguishing ischemic from nonischemic dilated cardiomyopathy.
BACKGROUND
Clinically, ischemic and nonischemic (idiopathic) dilated cardiomyopathy may be difficult to distinguish. Radionuclide ventriculography and exercise testing with thallium-201 scintigraphy are often used in an attempt to differentiate them noninvasively. With these techniques, the presence of (1) left ventricular (LV) regional asynergy, (2) depressed LV systolic function with normal right ventricular function, and/or (3) thallium-201 perfusion abnormalities traditionally has been regarded as evidence of ischemic heart disease. We assessed the incidence with which these abnormalities occur in patients with nonischemic-dilated cardiomyopathy.


METHODS
Seventy-six patients (45 men, 31 women, aged 18 to 75 years) with invasively proven nonischemic-dilated cardiomyopathy underwent radionuclide ventriculography (n = 75) and provocative thallium-201 perfusion imaging (n = 17).


RESULTS
Regional LV wall motion abnormalities were noted in 48% of patients, and 54% had LV systolic dysfunction without concomitant right ventricular dysfunction. Reversible and/or fixed exercise-induced thallium-201 perfusion abnormalities occurred in 94% of the patients studied.


CONCLUSIONS
Radionuclide ventriculography and exercise testing with thallium perfusion imaging cannot be used reliably to differentiate ischemic from nonischemic dilated cardiomyopathy, since many patients with the latter have radionuclide evidence of LV segmental wall motion abnormalities, selective LV systolic dysfunction, and segmental perfusion abnormalities.
Glamann
D B
DB
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235.
Lange
R A
RA
Corbett
J R
JR
Hillis
L D
LD
D000293:Adolescent; D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D003327:Coronary Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003937:Diagnosis, Differential; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015635:Radionuclide Ventriculography; D013794:Thallium Radioisotopes; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right
D013794:Thallium Radioisotopes