Acute effects of hemodialysis on echographic-determined cardiac performance: improved contractility resulting from serum increased calcium with reduced potassium despite hypovolemic-reduced cardiac output.

The hemodialysis session leads to reduction in circulating blood volume (TBV) and arterial pressure (BP) plus correction of electrolyte imbalance. The effect of these alterations on cardiac performance was evaluated in 18 patients with end-stage renal disease. Hemodialysis for 5 hours led to significant reduction (p less than 0.001) in weight TBV, and BP. Neither ejection fraction nor percentage fiber shortening was altered, whereas mean velocity of circumferential fiber shortening (mean VCF) and mean systolic ejection rate (MSER) were both significantly increased (1.17 +/- 0.20 to 1.38 +/- 0.28 circ/sec and 2.38 +/- 0.27 to 2.80 +/- 0.40 EDV/sec, respectively; p less than 0.001 for each). Since both venous return and systolic BP were decreased, increase in velocity of ventricular contraction implies enhancement of cardiac performance beyond what would be expected from alterations in ventricular filling and resistance to ejection. This enhancement is possibly related to concomitant reduction in serum potassium (p less than 0.001) and increase in serum calcium (p less than 0.005) achieved by hemodialysis.