Reversibility of abnormal arterial baroreflex control of heart rate in heart failure.

The reversibility of the abnormalities in arterial baroreceptor control of heart rate in heart failure was examined in an experimental model of canine high-output biventricular failure produced by an arteriovenous fistula that could be later surgically corrected by ligation. Marked attenuation of arterial baroreceptor control of heart rate in response to both hypertensive and hypotensive stimuli was seen in this model of heart failure. After surgical correction the heart rate response to a hypertensive stimulus did not return to normal but remained severely blunted for up to 8 mo of follow-up. The lack of reversibility after surgical correction suggests that permanent structural changes in arterial baroreceptors may occur after heart failure of short duration.