Abstract
An experimental animal model of hibernating myocardium is presented. Sixteen animals were initially prepared of which seven were selected for final review. Hearts were instrumented in two separate surgical procedures such that maximum phasic flow velocity in the left anterior descending (LAD) coronary artery was reduced by 50% and followed over 1 wk. Regional shortening declined at 1 wk to 62% of aerobic values (P < 0.048) and did not improve over 2 h reperfusion. Metabolic determinations, obtained after 1 wk of coronary stenosis and immediately sampled before and after release of the LAD flow constrictor, showed no evidence of acidosis, hypercarbia, or an inability to extract oxygen at the tissue level. Thereafter, during the 2-h reperfusion period, hearts were able to respond to dobutamine (10 μg/kg infusion over 1 min) challenge with an appropriate shift in an endsystolic length estimate of contractility. Mitochondrial respiration at the conclusion of the studies in the reperfused bed demonstrated near normal recovery compared with aerobic values. None of the seven hearts showed gross evidence of infarction and only one heart was noted to have a few microfocal changes of healing infarction. Thus a new model of coronary stenosis is presented, which affected substantial reductions in mechanical function consistent with the concepts of hibernating myocardium. These mechanical events were not associated with marked metabolic abnormalities, reflecting advanced ischemia or mitochondrial dysfunction and could be transiently improved with inotropic stimuli. This model may prove beneficial as a tool in understanding mechanistic events underlying the hibernating heart.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 263 |
| Issue number | 1 32-1 |
| State | Published - Jan 1 1992 |
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Keywords
- dobutamine challenge
- mechanical dysfunction
- mitochondrial respiration
- reactive hyperemia
ASJC Scopus subject areas
- Physiology
Cite this
An animal model of chronic coronary stenosis resulting in hibernating myocardium. / Bolukoglu, H.; Liedtke, A. J.; Nellis, S. H.; Eggleston, A. M.; Subramanian, R.; Renstrom, B.
In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 263, No. 1 32-1, 01.01.1992.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An animal model of chronic coronary stenosis resulting in hibernating myocardium
AU - Bolukoglu, H.
AU - Liedtke, A. J.
AU - Nellis, S. H.
AU - Eggleston, A. M.
AU - Subramanian, R.
AU - Renstrom, B.
PY - 1992/1/1
Y1 - 1992/1/1
N2 - An experimental animal model of hibernating myocardium is presented. Sixteen animals were initially prepared of which seven were selected for final review. Hearts were instrumented in two separate surgical procedures such that maximum phasic flow velocity in the left anterior descending (LAD) coronary artery was reduced by 50% and followed over 1 wk. Regional shortening declined at 1 wk to 62% of aerobic values (P < 0.048) and did not improve over 2 h reperfusion. Metabolic determinations, obtained after 1 wk of coronary stenosis and immediately sampled before and after release of the LAD flow constrictor, showed no evidence of acidosis, hypercarbia, or an inability to extract oxygen at the tissue level. Thereafter, during the 2-h reperfusion period, hearts were able to respond to dobutamine (10 μg/kg infusion over 1 min) challenge with an appropriate shift in an endsystolic length estimate of contractility. Mitochondrial respiration at the conclusion of the studies in the reperfused bed demonstrated near normal recovery compared with aerobic values. None of the seven hearts showed gross evidence of infarction and only one heart was noted to have a few microfocal changes of healing infarction. Thus a new model of coronary stenosis is presented, which affected substantial reductions in mechanical function consistent with the concepts of hibernating myocardium. These mechanical events were not associated with marked metabolic abnormalities, reflecting advanced ischemia or mitochondrial dysfunction and could be transiently improved with inotropic stimuli. This model may prove beneficial as a tool in understanding mechanistic events underlying the hibernating heart.
AB - An experimental animal model of hibernating myocardium is presented. Sixteen animals were initially prepared of which seven were selected for final review. Hearts were instrumented in two separate surgical procedures such that maximum phasic flow velocity in the left anterior descending (LAD) coronary artery was reduced by 50% and followed over 1 wk. Regional shortening declined at 1 wk to 62% of aerobic values (P < 0.048) and did not improve over 2 h reperfusion. Metabolic determinations, obtained after 1 wk of coronary stenosis and immediately sampled before and after release of the LAD flow constrictor, showed no evidence of acidosis, hypercarbia, or an inability to extract oxygen at the tissue level. Thereafter, during the 2-h reperfusion period, hearts were able to respond to dobutamine (10 μg/kg infusion over 1 min) challenge with an appropriate shift in an endsystolic length estimate of contractility. Mitochondrial respiration at the conclusion of the studies in the reperfused bed demonstrated near normal recovery compared with aerobic values. None of the seven hearts showed gross evidence of infarction and only one heart was noted to have a few microfocal changes of healing infarction. Thus a new model of coronary stenosis is presented, which affected substantial reductions in mechanical function consistent with the concepts of hibernating myocardium. These mechanical events were not associated with marked metabolic abnormalities, reflecting advanced ischemia or mitochondrial dysfunction and could be transiently improved with inotropic stimuli. This model may prove beneficial as a tool in understanding mechanistic events underlying the hibernating heart.
KW - dobutamine challenge
KW - mechanical dysfunction
KW - mitochondrial respiration
KW - reactive hyperemia
UR - http://www.scopus.com/inward/record.url?scp=0026655462&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026655462&partnerID=8YFLogxK
M3 - Article
VL - 263
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
SN - 0363-6135
IS - 1 32-1
ER -