Blood pressure and ejection fraction changes due to ultrafiltration in hemodialysis

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.

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

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).

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.