Arterial baroreflex sensitivity is a good predictor of inotropic responses to a phosphodiesterase inhibitor in human heart failure.
BACKGROUND
Experimental study has shown that blunted arterial baroreflex function markedly attenuated inotropic responses to a phosphodiesterase inhibitor (PDEI) even in normal hearts. However, whether arterial baroreflex function is related to the inotropic responsiveness to a PDEI has not been clarified in human heart failure (HF).


OBJECTIVE
The goal of this study was to examine the relationship between inotropic responses to a PDEI and arterial baroreflex sensitivity in human HF.


METHODS
Twelve patients with HF were examined, and hemodynamic responses to milrinone (12.5, 25, and 50 microg/kg, intravenous injection) and arterial baroreflex sensitivity were assessed by pulse interval-left ventricular (LV) systolic pressure slope using nitroglycerin and phenylephrine.


RESULTS
Milrinone (25 microg/kg) significantly increased LV dP/dt. Arterial baroreflex sensitivity was only one predictor of inotropic responses to milrinone by multivariate analysis; a strong positive correlation was also found between LV dP/dt and baroreflex sensitivity (y = 6.656X - 3.326, r = 0.93, p = 0.000).


CONCLUSIONS
Inotropic effects of milrinone, a PDEI, correlated significantly with arterial baroreflex sensitivity, suggesting that the more baroreflex function was impaired, the more the inotropic effect of a PDEI was depressed in human HF.
Sato
Naoki
N
Intensive and Cardiac Care Unit, Nippon Medical School, Tokyo, Japan. nms-ns@nms.ac.jp
Yamamoto
Takeshi
T
Akutsu
Koichi
K
Fujita
Nobuhiko
N
Asai
Kuniya
K
Takayama
Morimasa
M
Takano
Teruo
T
Tanaka
Keiji
K
D000328:Adult; D000368:Aged; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D011311:Pressoreceptors / Q000502:physiology*
D002316:Cardiotonic Agents; D010726:Phosphodiesterase Inhibitors; D020105:Milrinone