The aim of this study was to assess left ventricular (LV) systolic and diastolic function and myocardial performance (the Tei index) by tissue Doppler imaging (TDI) in patients with primary hyperparathyroidism (PHPT). We prospectively evaluated 21 patients with PHPT [nine women, 12 men; aged 50 +/- 11 years, serum calcium 2.9 +/- 0.17 mmol/l, intact PTH (iPTH) 51.5 +/- 52.1 pmol/l] and 27 healthy control subjects (13 women, 14 men; aged 49 +/- 10 years, serum calcium 2.35 +/- 0.12 mol/l, iPTH 2.9 +/- 0.9 pmol/l). LV systolic and diastolic function was assessed by conventional echocardiography and by TDI. Early diastolic (Em), late diastolic (Am) and peak systolic (Sm) mitral annular velocities, the ratio Em/Am and the Tei index were calculated from TDI measurements. Mitral inflow velocities, colour M-mode flow propagation velocity (Vp), relative wall thickness (RWT) and LV mass index (LVMI) were assessed by two-dimensional echocardiography. Em and Em/Am were lower in patients with PHPT than in healthy controls (11.2 +/- 1.5 cm/s vs. 13.5 +/- 2.5 cm/s, P = 0.005; 0.94 +/- 0.27 vs. 1.36 +/- 0.44, P = 0.02, respectively). In patients with PHPT, the Tei index was significantly higher than that in controls (0.45 +/- 13.6 vs. 0.33 +/- 8.1, P = 0.02). Peak (E) velocity and the ratio of E to peak late (A) velocity (E/A) were lower in those with PHPT than in those without (59 +/- 15 cm/s vs. 72 +/- 19 cm/s, P = 0.02; 0.8 +/- 0.15 vs. 1.1 +/- 0.33, P = 0.001, respectively). Patients with PHPT had significantly higher RWT (0.50 +/- 0.02 cm vs. 0.41 +/- 0.02 cm, P = 0.0001), isovolumetric relaxation time (IVRT) (115 +/- 13 ms vs. 103 +/- 11 ms P = 0.04) and A velocity (79 +/- 16 cm/s vs. 68 +/- 13 cm/s P = 0.05) than controls. Vp was lower in PHPT patients than in healthy subjects (42 +/- 9.98 cm/s vs. 54 +/- 19.01 cm/s P = 0.04). There were no significant differences between the two groups regarding LV end-diastolic and end-systolic dimensions, LVMI, deceleration time of the mitral E wave, Am and Sm. TDI analysis of mitral annular velocities, Em/Am and the Tei index is useful for assessing LV diastolic dysfunction in patients with PHPT. The parameters obtained from the lateral mitral annulus by TDI can be used for the identification of LV diastolic dysfunction in PHPT patients.