Effects of dobutamine on ischemic vasodilation of the forearm in patients with severe congestive heart failure.

BACKGROUND

The significant changes that occur in the peripheral circulatory system in heart failure are well known. Although the central hemodynamic effects of dobutamine have been well described, data on its effect on peripheral vascular function in patients with severe left ventricular dysfunction are limited.

METHODS AND RESULTS

Resting and hyperemic forearm blood flow and resistance were measured using forearm venous occlusion plethysmography in patients with advanced congestive heart failure (CHF) before and during the infusion of increasing doses of dobutamine. Total hyperemia was also calculated. We studied eight patients with New York Heart Association classes III to IV CHF who had a mean age of 62 +/- 5 years and a mean ejection fraction of 17.4% +/- 2.9%. Resting forearm blood flow increased from 2.3 +/- 0.2 to 3.4 +/- 0.4 mL/min/100 mL during peak dobutamine infusion (P < .05). Resting forearm vascular resistance decreased from 39 +/- 3 to 29 +/- 4 units (P < .02). Peak hyperemic forearm blood flow increased from 25 +/- 3 to 34 +/- 6 mL/min/100 mL of tissue (P < .02) and peak hyperemic vascular resistance decreased from 3.7 +/- 0.4 to 2.9 +/- 0.3 units (P < .01). Total hyperemia increased from 14.3 +/- 1.9 to 19.4 +/- 2.4 mL/100 mL (P < .01).

CONCLUSIONS

The data show that in patients with advanced CHF, intravenous dobutamine not only increases resting forearm blood flow and decreases resting forearm vascular resistance, but augments the reactive hyperemic flow and improves the vasodilatory response of the forearm vessels to transient ischemic occlusion. The underlying mechanism for this response and its clinical significance remain to be identified.