[Study of diastolic function in peritoneal dialysis patientes. Comparison between pulsed and Tissue Doppler]

Left ventricular hypertrophy (LVH) is the main expression of uremic cardiomyopathy. Alteration of the diastolic function is frequently associated with LVH, indicating future cardiovascular events. Recent studies suggest that the Tissue Doppler (TID) of the mitral annulus obtains parameters of diastolic function that are not influenced by other factors, unlike what occurs with the pulsed Doppler (PD), and that the relationship between the velocity of the proto-diastolic waves of both techniques (E/E') would be the most important datum to diagnose a diastolic malfunction. The objective of this study is to verify LVH prevalence in a population of End Stage Renal Disease patients (ESRD) in peritoneal dialysis (CAPD), and to study diastolic function, comparing the results of both techniques (PD/TID), as well as the possible causes that determine the appearance of diastolic malfunction in these patients.

We carried out a cross-section study with 42 patients in peritoneal dialysis. All patients had an ejection fraction of over 50% and had no clinical signs of heart failure, valvular heart disease or arrhytmia. A basic biochemistry, residual renal function, C-reactive protein and an ultrasonic study with M-mode doppler, pulsed doppler and tissue doppler of the mitral annulus, were performed in all patients.

26.2% of the patients had a concentric LVH, 14.3% an asymmetric LVH and 23.8% a concentric growth. The PD showed an E/A ratio under 0.75 in 20 cases (which would indicate an alteration of ventricular relaxation), an E/A between 0.75 and 1.5 in 22 (normal or pseudonormal pattern) and none with an E/A over 1.5. On the other hand, the TID showed: 24 patients with an E/A < 0.75, 16 between 0.75 and 1.5, and 2 with an E/A > 1.5. The E/E' proportion was normal in 13 cases(< 8), intermediate in 12 (8-10), and greater than 10 in 17, expressing a clear diastolic malfunction. Twelve of the 17 with diastolic malfunction had a pseudo-normal pattern with the PD. A relationship was observed between the E/A and age and hs-CRP. A relationship was also found between RRF, ejection fraction and diastolic pressure (p = 0.03, r = 0.32 and p = 0.006, r = 0.29), while, in the multivariant study, the presence of LVH was the only variable with enough significance to influence the diastolic malfunction (odds ratio of 7.6).

Patients in CAPD have a high incidence of diastolic malfunction. LVH, present in a high percentage of patients, is one of the factors that favours its appearance. The non-invasive TID technique and the E/E' ratio have shown to be more sensitive than the PD in diagnosing a diastolic malfunction.