[Cardiac involvement in systemic amyloidosis: myocardial scintigraphic evaluation]

To assess the clinical significance of technetium-99m-pyrophosphate (Tc-99m-PYP), -methylene diphosphonate (Tc-99m-MDP) and thallium-201 (Tl-201) myocardial scintigraphy in the diagnosis of cardiac amyloidosis and in the differential diagnosis of cardiac diseases, 12 patients with biopsy-proved systemic amyloidosis (seven with familial amyloid polyneuropathy (FAP) and five with primary amyloidosis) were investigated. The results obtained were as follows: In 10 patients (six with FAP and four with primary amyloidosis) studied by Tc-99m-PYP scintigraphy, two (FAP one, primary amyloidosis one) had diffusely positive myocardial uptake, which was of greater intensity than that of the sternum. Six (four FAP; two primary amyloidosis) also had diffusely positive myocardial uptakes, but the intensity was less than that of the sternum. The remaining two (one FAP; one primary amyloidosis) had only equivocal myocardial uptakes. Two of these patients also had hepatic uptakes and another had both hepatic and thyroid uptakes. The intensity of myocardial uptake of Tc-99m-PYP in patients with echocardiographic left ventricular hypertrophy and/or highly refractile myocardial echoes, so-called granular sparkling appearance (GS) was slightly greater than that in patients with neither myocardial hypertrophy nor GS. FAP had slightly less intensity than primary amyloidosis. In 29 persons with other cardiac diseases and normal subjects examined by Tc-99m-PYP scintigraphy, seven (two dilated cardiomyopathy; two sarcoidosis; three hypertensive heart disease) also had diffusely positive myocardial scans of mild or moderate degree. However, none of them had marked myocardial or other tissue uptakes. Both Tc-99m-PYP and -MDP scintigraphic studies were performed in four patients (three FAP; one primary amyloidosis). In Tc-99m-MDP scintigraphy, diffusely positive myocardial uptakes were observed in two patients with FAP and the remaining two had negative scans. The intensity of Tc-99m-MDP myocardial uptake in each patient was significantly lower than that of Tc-99m-PYP uptake. Tl-201 scintigraphy was carried out in 10 patients (six FAP; four primary amyloidosis). Left ventricular hypertrophy was found in six patients and right ventricular visualization in five. Although electrocardiograms in seven of 10 patients showed QS patterns in the right to mid precordial leads, similar to that seen in antero-septal and extensive anterior myocardial infarctions, neither myocardial perfusion defect nor low uptake on Tl-201 images was detected in nine of them. The scintigrams in another one, which showed low uptake at the apical portion of the left ventricle, were considered normal.(ABSTRACT TRUNCATED AT 400 WORDS)