OBJECTIVE We examined the cardiac function of patients who underwent Tc-99m sestamibi quantitative gated myocardial single photon emission computed tomography with 16-framing data acquisition between January 1, 2004 and March 31, 2006 for an evaluation of suspected or known heart disease in our hospital. METHODS In 192 patients aged >or=40 years, the left ventricular (LV) systolic function [parameter: ejection fraction (EF)] and diastolic function [first third filling fraction (1/3FF), peak filling rate (PFR), and time-to-peak filling (TPF)] were estimated by volume curve analysis. In 51 (age >or=60 years) of 192 patients, brachial-ankle pulse wave velocity (baPWV) was also measured. RESULTS The correlation between diastolic parameters PFR and 1/3FF was mild (r = 0.28, P < 0.001). On the basis of EF and PFR, 192 patients were divided into four groups: P (preserved LV function), Q (isolated systolic dysfunction, EF < 50%), R (isolated diastolic dysfunction, PFR < 1.8 EDV/s), and S (both dysfunctions). The numbers of patients in P, Q, R, and S groups were 94 (49.0%), 7 (3.6%), 31 (16.1%), and 60 (31.3%), respectively. The 1/3FF correlated weakly but significantly with age (r = -0.16, P < 0.05). The TPF also correlated weakly with age (r = 0.25, P < 0.01), but EF did not. The baPWV, an indicator of cardiovascular stiffness, correlated inversely with 1/3FF (r = -0.59, P < 0.001) or correlated positively with TPF (r = 0.45, P < 0.001), but not with EF. CONCLUSIONS Our study suggests that cardiovascular stiffness associated with increased baPWV may contribute to the occurrence of diastolic dysfunction in elderly patients.