Effect on peripheral arterioles of chronic fluid and sodium retention in heart failure

To determine whether chronic fluid and sodium retention in heart failure adversely affects peripheral arteriolar behavior, systemic vascular resistance and skeletal muscle vasodilation were compared in eight control dogs and nine dogs with chronic fluid and sodium retention (ascites = 2.3 +/- 2.3 liters) induced by rapid ventricular pacing for 2 months. At rest, both groups exhibited comparable systemic vascular resistance (control 45 +/- 14 versus heart failure 40 +/- 7 U) and femoral bed vascular resistance (control 18.7 +/- 6.9 versus heart failure 19.0 +/- 7.2 x 10(2) U) (both p = NS). Femoral bed resistance also decreased similarly in both groups during treadmill exercise (resistance at peak exercise: control 4.7 +/- 3.0 versus heart failure 4.9 +/- 0.9 x 10(2) U [p = NS]). In isolated gracilis muscle, vascular resistance was also comparable in both groups at rest (control 7.3 +/- 3.3 versus heart failure 10.2 +/- 3.6 x 10(3) U/100 g), at peak exercise (control 1.6 +/- 0.5 versus heart failure 1.8 +/- 0.9 x 10(3) U/100 g) and after maximal vasodilation with papaverine (control 0.7 +/- 0.3 versus heart failure 0.9 +/- 0.3 x 10(3) U/100 g) (all p = NS). These data suggest that chronic fluid and sodium retention in heart failure does not alter peripheral arteriolar behavior.