These results show a reduced ability to excrete a sodium load and early abnormalities of cardiac and hemodynamic adaptations to salt excess in patients with mild heart failure and no signs or symptoms of congestion.

(1) Renal functional reserve is absent in patients with early/asymptomatic HF and normal renal function and (2) both enalapril and losartan restore a normal vasodilatory response to AA in these patients without affecting basal systemic and renal hemodynamics. These data suggest a major role of AII in the development of early abnormalities in patients with HF.

To investigate whether the response of atrial natriuretic factor (ANF) to volume expansion is impaired in the early stages of dilated cardiomyopathy, the effects of saline load (SL; 0.25 ml/kg. min for 120 min) were assessed in 12 patients with dilated cardiomyopathy and asymptomatic to mildly symptomatic heart failure (HF) and in nine normal subjects (N). SL increased plasma ANF levels in N (from 143±2 to 19.5±3 and 26±4 pg/ml, at 60 and 120 min, respectively, P < 0.001), but not in HF (from 42.9±9 to 45.9±9 and 43.9±8 pg/ml). Left ventricular end-diastolic volume (LVEDV) and stroke volume were increased (P < 0.001) by SL in N but not in HF. Urinary sodium excretion (UNSY) increased in N more than in HF during SL, whereas forearm vascular resistance (FVR) did noi change in N and increased in HF (P < 0.001). In five HF patients SL was performed during ANF infusion (50 ng/kg, 5 ng/kg min) that increased ANF levels from 37.1±10 to 146±22 pg/ml. In this group, SL raised both LVEDV (P < 0.01) and ANF (P < 0.05), whereas FVR did not rise. In addition, the UN.V increase and renin and aldosterone suppressions by SL were more marked than those observed in HF under control conditions. Thus, in patients with dilated cardiomyopathy and mild cardiac dysfunction, plasma ANF levels are not increased by volume expansion as observed in N. The lack of ANF response is related to the impaired cardiac adaptations. The absence ofan adequate increase ofANF levels may contribute to the abnormal responses of HF patients to saline load. (J.

The need for permanent pacemaker implantation is increased after concomitant tricuspid ring annuloplasty in the setting of mitral valve surgery. A clinical period of observation up to 14 days after postoperative heart conduction disorders should be observed before recommending permanent pacemaker placement.