Background: The disadvantageous effect of kidney dysfunction on left ventricular (LV) diastolic function is still unknown.
Methods: Forty non-chronic kidney disease (CKD) patients and 202 CKD patients, aged 40-89, were examined by standard echocardiography and the new modality of tissue Doppler imaging. All subjects were divided into 5 groups depending on their estimated glomerular filtration rate (GFR: ml/min/BSA). Classifications by GFR were defined as follows: group 1 (more than 90: normal subjects), group 2 (60-89), group 3 (30-59), group 4 (15-29) and group 5 (less than 15).
Results: There were no significant differences in LV systolic function among the groups. Mitral E velocity was significantly lower in groups 1-4 (p<0.01-0.02) compared with group 5. Mitral A velocity was higher in groups 2-5 (p<0.01-0.04) compared with group 1. The ratio of mitral E and A velocities (E/A) was significantly higher in group 1 (p<0.02-0.05) compared with groups 2-5. Deceleration time was significantly shorter in groups 1 and 2 (p<0.01-0.02) compared with groups 4 and 5. Furthermore, it was significantly lower in group 5 (p<0.01) compared with group 4. Early diastole velocity of mitral annulus (Ea) by tissue Doppler was also higher in group 1 (9.1+/-2.5; p<0.01-0.04) compared with group 2 (7.9+/-1.7), group 3 (7.9+/-1.6), group 4 (7.5+/-2.1), and group 5 (7.6+/-2.0). Severity of the kidney dysfunction appears to parallel with the rise of E/Ea significantly (p<0.02). A, E/A and Ea could differentiate between groups 1 and 2 with early stage of CKD.
Conclusions: These data suggest that LV diastolic dysfunction was observed even in patients with early stages of chronic kidney dysfunction. Doppler indices combined with conventional and tissue Doppler methods could detect the subtle changes of diastolic function due to kidney dysfunction.