Cardiac function and cardiovascular hormone balance during hemodialysis with special reference to atrial natriuretic peptide.

Echocardiographically determined left ventricular function and cardiovascular hormone balance were assessed before and after hemodialysis in 10 patients who had been on hemodialysis for 4 months to 15 years. Plasma levels of atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), renin activity and aldosterone were determined. All patients had vector- and echocardiographic evidences of slight to moderate left ventricular hypertrophy. The body weight decreased 2.0 kg (3.3 +/- 0.5%) with dialysis. Nine out of ten patients showed a slightly reduced ejection fraction that normalized after dialysis (p less than 0.05). Left atrial and ventricular systolic dimensions were around the upper reference limit before dialysis with a decrease after dialysis (p less than 0.05 and p less than 0.02, respectively). The levels of ANP decreased with dialysis from 2-17 times to 1 to 15 times the upper reference value in nine out of the ten patients. In the whole group the decrease was 117 +/- 35% (p less than 0.005). A significant regression was obtained between percentage decrease of body weight and percentage change of ANP (r = 0.67; p less than 0.05). The plasma concentration of ADH did not change following dialysis but the mean value was significantly higher than the mean value of the reference group of the laboratory (p less than 0.05 before and p less than 0.005 after dialysis). Renin activity and aldosterone levels were low and did not change during dialysis. In conclusion, the slight left ventricular hypertrophy may partly be a response to volume overload with hyperdynamic circulation and partly to metabolically depressed myocardial function.(ABSTRACT TRUNCATED AT 250 WORDS)