Blood pressure and ejection fraction changes due to ultrafiltration in hemodialysis.

Background: Nocturnal hypertension (NH) is an unsolved problem in hemodialysis (HD) patients. The effect of ultrafiltration (UF) on NH and myocardial performance has not been systematically investigated in HD patients.

Methods: Seventeen reverse-dipper (RD) HD patients were subjected to intensified UF. Before and after UF, echo-cardiographic and blood pressure (BP) measurements were taken.

Results: Excluding daytime diastolic BP, all BP parameters (mmHg), namely daytime systolic BP (138.1 +/- 15.1; 131.1 +/- 12.5), night-time systolic BP (150.4 +/- 17.6; 125.3 +/- 16.5), night-time diastolic BP (87.3 +/- 10.3; 76.5 +/- 11.6), daytime pulse pressure (56.1 +/- 7.6; 50.5 +/- 5), night-time pulse pressure (63.3 +/- 9.4; 48.7 +/- 7), significantly decreased (p < 0.001 for all comparisons). Thirteen patients converted to non-dipper and two patients converted to dippers, whereas two patients remained on RD. Unit for measurement of diameters was mm. Ejection fractions (EF) increased (51.23 +/- 9.01; 64.05 +/- 7.23, p < 0.001), left atrial diameters (LAD) decreased (35 +/- 8.29; 32.05 +/- 7.12, p < 0.001), the vena cava inferior collapse index increased (VCICI) [24.82 +/- 8.20 (%); 51.76 +/- 9.65 (%), p < 0.001], left ventricular end-systolic (LVES) and diastolic diameters (LVED) decreased (3.19 +/- 0.60; 2.77 +/- 0.51, p < 0.001; 4.39 +/- 0.65; 4.18 +/- 0.56, p = 0.002, respectively). Percentage reduction in night-time diastolic BP correlated with the percentage reduction in LAD (p = 0.038). Percentage reduction in night-time pulse pressure correlated with the percentage increase in EF (p < 0.013). Similarly, percentage reductions in night-time systolic BP, night-time diastolic BP and night-time mean BP correlated with the percentage reduction in LVESD (p = 0.014, p < 0.001 and p = 0.001, respectively).

Conclusions: NH in HD patients is a volume dependent phenomenon. Improved night-time BP parameters have a more profound effect on myocardial function than daytime BP parameters.