Parasympathetic negative inotropic denervation supersensitivity of
the transplanted human ventricle in vivo.
Koglin, J[diaeresis]org, Peter [umlaut]uberfuhr, Wolfgang Von Scheidt,
Medizinische Klinik I, and Herzchirurgische Klinik, Klinikum
Grosshadern.
University of Munich, Marchioninistr. 15, D-81377 Munich,
Germany
APStracts 3:0034H, 1996.
Sympathetic inotropic supersensitivity after transplantation
-associated denervation of the cardiac autonomic nervous system has
been described in humans previously. Potential changes of the
parasympathetic regulation of the human ventricular contractility
have not been investigated yet. We studied the antiadrenergic
negative inotropic effect of carbachol (3.6 [mu]g/kg) during
continuous [beta]-adrenergic stimulation (isoproterenol 20 ng/kg X
min) in seven heart transplant recipients and seven healthy controls.
Changes in ventricular contractility were calculated as increase from
baseline of the systolic pressure/dimension ratio (_P/D) and of the
rate-corrected velocity of circumferential fiber shortening (_Vcfc)
using M-mode echocardiography. In the control group the
isoproterenol-induced increase in contractility was attenuated only
insignificantly by carbachol (_P/D from 1.53+/-0.53 mmHg/mm to
0.81+/-0.55 mmHg/mm, _Vcfc from 0.77+/-0.20 [square root]min-1x %/ms
to 0.63+/-0.22 [square root]min-1x %/ms). In contrast, the transplant
group exhibited a significant reduction of the isoproterenol-induced
increase in contractility (_P/D from 1.27+/-0.71 mmHg/mm to -0.81+/
-0.51 mmHg/mm (p<0.01), _Vcfc from 1.04+/-0.84 [square root]min
-1x%/ms to 0.04+/-0.43 [square root]min-1x%/ms (p<0.01)). These
data are consistent with parasympathetic indirect negative inotropic
supersensitivity of the transplanted human heart in vivo.
Received 30 May 1995; accepted in final form 16 January 1996.
APS Manuscript Number H492-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 January 96