TY - JOUR
T1 - Right coronary autoregulation in conscious, chronically instrumented dogs
AU - Bian, Xiaoming
AU - Williams, Arthur G.
AU - Gwirtz, Patricia A.
AU - Downey, H. Fred
PY - 1998/7
Y1 - 1998/7
N2 - Right coronary (RC) autoregulation and right ventricular (RV) function were assessed in conscious dogs, chronically instrumented to measure RC flow and RC pressure (RCP) as a hydraulic occluder on the RC was inflated. Dogs were then anesthetized, and RC autoregulation and RV function were again assessed. In the conscious state, moderate RC autoregulation was present with closed loop gains (G(c)) of 0.59-0.27 as RCP was reduced from 100 to 40 mmHg. In the anesthetized state, G(c) was not significantly less than in the conscious state at RCP >50 mmHg. The range and potency of RV autoregulation were greater in both groups than for previously reported findings in anesthetized dogs with RC perfused by an extracorporeal system. RV contractile function was well maintained in conscious and anesthetized dogs at RCP >45 mmHg. We conclude the following: 1) modest RC autoregulation is present in the conscious dog, 2) anesthesia limits the range but not the degree of RC autoregulation, 3) extracorporeal perfusion systems appear to depress RC autoregulation, and 4) RV contractile function remains constant in both conscious and anesthetized dogs until RCP falls below 50 mmHg.
AB - Right coronary (RC) autoregulation and right ventricular (RV) function were assessed in conscious dogs, chronically instrumented to measure RC flow and RC pressure (RCP) as a hydraulic occluder on the RC was inflated. Dogs were then anesthetized, and RC autoregulation and RV function were again assessed. In the conscious state, moderate RC autoregulation was present with closed loop gains (G(c)) of 0.59-0.27 as RCP was reduced from 100 to 40 mmHg. In the anesthetized state, G(c) was not significantly less than in the conscious state at RCP >50 mmHg. The range and potency of RV autoregulation were greater in both groups than for previously reported findings in anesthetized dogs with RC perfused by an extracorporeal system. RV contractile function was well maintained in conscious and anesthetized dogs at RCP >45 mmHg. We conclude the following: 1) modest RC autoregulation is present in the conscious dog, 2) anesthesia limits the range but not the degree of RC autoregulation, 3) extracorporeal perfusion systems appear to depress RC autoregulation, and 4) RV contractile function remains constant in both conscious and anesthetized dogs until RCP falls below 50 mmHg.
KW - Right coronary circulation
KW - Right ventricular function
UR - http://www.scopus.com/inward/record.url?scp=33750879543&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.1998.275.1.h169
DO - 10.1152/ajpheart.1998.275.1.h169
M3 - Article
C2 - 9688910
AN - SCOPUS:33750879543
SN - 0363-6135
VL - 275
SP - H169-H175
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 1 44-1
ER -