Hemodialysis induces circulatory changes also related to changes in body fluid content and plasma volume. These adjustments imply changes in several aspects of cardiac function - contractility and diastolic function - and in the peripheral circulation. Bio-electric impedance analysis (BIA) is useful in nutritional medicine to assess fat-free mass (FFM) and fat mass (FAT) and provides, among other findings, total body water (TBW) and its distribution in intracellular (ICW) and extracellular (ECW) compartments. This study used BIA and echocardiography to assess the effects of body water content changes on cardiac function in patients on maintenance dialysis. We studied 23 patients (12 m and 11 f), mean age 60.1 ± 12.7 years, mean dialytic age 51.78 ± 59.6 months. With hemodialysis there was a significant decrease of TBW% and of ECW%, with a reciprocal increase of ICW%. Significant decreases of body weight, systolic blood pressure (Syst. BP), left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (CO), ejection fraction (EF) and mean velocity of circumferential fiber (mVCF) were observed. Changes in ECW% correlated directly with LVESV (r=0.59, p<0.003) and inversely with mVCF (r=-0.55, p<0.007). Changes of cardiac EF showed a significant negative correlation (r=-0.74; p<0.001) with changes of ECW%. Body weight and TBW were not significantly related with echocardiographic changes. Comparison of the 12 patients with Δ ECW >3% (mean loss 4.11 ± 1.64) and the 11 patients with Δ ECW <3% (mean loss 2.07 ± 0.57), without differences in dialytic weight losses, showed very different cardiac and blood pressure adjustments though the decrease of body weight and of TBW with dialysis did not significantly differ. Patients with a lower ECW loss had a more marked decrease of syst. BP and CO with dialysis. Moreover while patients with a higher ECW loss showed an increase in both systolic indexes (EF and mVCF), patients with less ECW loss had lower systolic function indexes. BIA seems a useful procedure for assessing body fluid compartments and their changes with hemodialysis, especially loss of ECW. We suggest that extracellular compartment fluid loss must reach a certain optimal level: excessively low levels seem inadequate to improve and even to maintain satisfactory contractile heart function.
Cardiac function and extracellular water relationship in hemodialysis
TROVATO, Guglielmo;
1996-01-01
Abstract
Hemodialysis induces circulatory changes also related to changes in body fluid content and plasma volume. These adjustments imply changes in several aspects of cardiac function - contractility and diastolic function - and in the peripheral circulation. Bio-electric impedance analysis (BIA) is useful in nutritional medicine to assess fat-free mass (FFM) and fat mass (FAT) and provides, among other findings, total body water (TBW) and its distribution in intracellular (ICW) and extracellular (ECW) compartments. This study used BIA and echocardiography to assess the effects of body water content changes on cardiac function in patients on maintenance dialysis. We studied 23 patients (12 m and 11 f), mean age 60.1 ± 12.7 years, mean dialytic age 51.78 ± 59.6 months. With hemodialysis there was a significant decrease of TBW% and of ECW%, with a reciprocal increase of ICW%. Significant decreases of body weight, systolic blood pressure (Syst. BP), left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (CO), ejection fraction (EF) and mean velocity of circumferential fiber (mVCF) were observed. Changes in ECW% correlated directly with LVESV (r=0.59, p<0.003) and inversely with mVCF (r=-0.55, p<0.007). Changes of cardiac EF showed a significant negative correlation (r=-0.74; p<0.001) with changes of ECW%. Body weight and TBW were not significantly related with echocardiographic changes. Comparison of the 12 patients with Δ ECW >3% (mean loss 4.11 ± 1.64) and the 11 patients with Δ ECW <3% (mean loss 2.07 ± 0.57), without differences in dialytic weight losses, showed very different cardiac and blood pressure adjustments though the decrease of body weight and of TBW with dialysis did not significantly differ. Patients with a lower ECW loss had a more marked decrease of syst. BP and CO with dialysis. Moreover while patients with a higher ECW loss showed an increase in both systolic indexes (EF and mVCF), patients with less ECW loss had lower systolic function indexes. BIA seems a useful procedure for assessing body fluid compartments and their changes with hemodialysis, especially loss of ECW. We suggest that extracellular compartment fluid loss must reach a certain optimal level: excessively low levels seem inadequate to improve and even to maintain satisfactory contractile heart function.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
