TREATMENT OF SUBCLINICAL FLUID RETENTION IN PATIENTS WITH SYMPTOMATICHEART-FAILURE - EFFECT ON EXERCISE PERFORMANCE

Background: Patients with heart failure frequently have elevated intra cardiac diastolic pressures but no clinical evidence of excess fluid r etention. We speculated that such pressure elevations may indicate sub clinical fluid retention and that removal of this fluid could improve exercise intolerance. Methods: To test this hypothesis, we studied 10 patients with right atrial pressure greater than or equal to 8 mm Hg b ut without rales, edema, or apparent jugular venous distension. Right- sided heart catheterization was performed, after which patients underw ent maximal treadmill cardiopulmonary testing. Patients were then hosp italized and underwent maximal diuresis, after which exercise was repe ated. Results: Before diuresis, right atrial pressure averaged 16 +/- 5 mm Hg (+/- standard deviation), pulmonary capillary wedge pressure 3 0 +/- 6 mm Hg, and peak exercise Vo(2) 11.2 +/- 2.3 ml/min/ kg. Patien ts underwent diuresis of 4.5 +/- 2.2 kg over 4 +/- 2 days to a resting right atrial pressure of 6 +/- 4 and wedge pressure of 19 +/- 7 mm Hg . After diuresis, all patients reported overall symptomatic improvemen t. Maximal exercise duration increased significantly from 9.2 +/- 4.2 to 12.5 +/- 4.7 minutes. At matched peak workloads, significant improv ements were also seen in minute ventilation (45 +/- 12 to 35 +/- 9 L/m in), lactate levels (42 +/- 16 to 29 +/- 9 mg/dl), and Borg dyspnea sc ores (15 +/- 3 to 12 +/- 4) (all p < 0.05). Conclusions: Invasive hemo dynamic monitoring allows the identification of excess fluid retention in patients with heart failure when there are no clinical signs of fl uid overload. Removal of this subclinical excess fluid improves exerci se performance and exertional dyspnea.