CLINICAL INVESTIGATIONS Diastolic Dysfunction in Patients with Systemic Sclerosis Detected by Gated Myocardial Perfusion SPECT: An Early Sign of Cardiac Involvement

Diagnosis of cardiac involvement is important for the manage-ment of patients with systemic sclerosis (SSc). This study was undertaken to determine the significance of gated myocardial perfusion SPECT in patients with SSc and whether diastolic function measured by gated SPECT is an early sign of cardiac complications. Methods: Thirty-four patients with SSc and 16 control patients were studied using exercise nongated and rest-ing gated myocardial perfusion SPECT. The SSc was classified by the modified Rodnan total skin score (TSS) into high-TSS (score $ 10; n 5 18) and low-TSS (score, 10; n 5 16) groups. Gated SPECT was performed using 99mTc-methoxyisobutyl-isonitrile with 16 frames per cardiac cycle and quantitatively analyzed by QGS software and Fourier filtering of the volume curve. The parameters of ejection fraction (EF), peak filling rate (PFR), one-third mean filling rate, and time to PFR (TPFR) were calculated. Results: A slight perfusion abnormality was ob-served in four and five patients in the low-TSS and high-TSS groups, respectively (not statistically significant). A decreased resting EF less than 55 % was found in no and two patients in the low-TSS and high-TSS groups, respectively. TPFR wa