DIASTOLIC DYSFUNCTION IN PATIENTS WITH RENAL-FAILURE

Left ventricular hypertrophy of the concentric or asymmetric-septal type is the most common pathological finding in the heart of dialysis patients, while heart size and left ventricular systolic function are usually within the normal range. A reduced left ventricular compliance (or increased myocardial stiffness) is frequently present, leading to compromised diastolic filling. Left ventricular hypertrophy and diffuse interstitial fibrosis of the myocardium have been demonstrated both in uremic animals and in dialysis patients. They are thought to be responsible for diastolic dysfunction. Clinical sequelae of the compromised diastolic filling consist of a propensity towards hemodynamic instability during hemodialysis on the one hand. Ultrafiltration causes a rapid fall of cardiac filling pressure that is necessary for the maintenance of an adequate cardiac output. On the other hand, affected patients are at an increased risk of developping pulmonary edema with relatively small increments of intravascular volume. During hemodialysis the lowest possible ultrafiltration rates should be sought. Therapeutic alternatives such as peritoneal dialysis or hemofiltration, where changes of extracellular volume and/or of the electrolyte composition occur less rapidly, should be considered in such patients.