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Ischemic threshold and myocardial stunning in the aging heart
- Source :
- Experimental Gerontology. 34:875-884
- Publication Year :
- 1999
- Publisher :
- Elsevier BV, 1999.
-
Abstract
- The aging heart appears to be more susceptible to ischemia-reperfusion injury than the adult heart. There is no evidence of an age-related difference in the threshold of myocardial ischemia and myocardial stunning. We studied the effects on mechanical, hemodynamic, and metabolic parameters of graded reduction of coronary perfusion pressure from 66 to 29 mmHg in isolated and perfused hearts from adult and senescent rats. Cardiac function was also assessed during recovery following ischemic period. In both adult and senescent hearts developed pressure and +dP/dt linearly decreased and end-diastolic pressure linearly increased with decreasing perfusion pressure. However, all mechanical parameters were more severely impaired in senescent than in adult hearts at 37 mmHg and 29 mmHg perfusion pressure, respectively (p < 0.01 vs. adult). At 29 mmHg, in both adult and senescent hearts lactate production similarly increased whereas creatine kinase leakage did not differ from controls. Developed pressure recovered more slowly in senescent than in adult hearts (p < 0.001) in the absence of cellular damage and in the presence of restoration of coronary flow. Lactate production observed at the same step of coronary perfusion pressure suggests that the ischemic threshold is similar in adult and senescent hearts. The slow recovery of myocardial contractility after the ischemic period observed in senescent hearts suggests an age-related increase in myocardial stunning.
- Subjects :
- Male
Cardiac function curve
Aging
medicine.medical_specialty
Myocardial ischemia
Hemodynamics
In Vitro Techniques
Biochemistry
Contractility
Endocrinology
Internal medicine
Genetics
medicine
Animals
Lactic Acid
Rats, Wistar
Creatine Kinase
Molecular Biology
Myocardial Stunning
Myocardial stunning
biology
business.industry
Heart
Cell Biology
medicine.disease
Rats
Coronary perfusion pressure
Cardiology
biology.protein
Creatine kinase
business
Perfusion
Subjects
Details
- ISSN :
- 05315565
- Volume :
- 34
- Database :
- OpenAIRE
- Journal :
- Experimental Gerontology
- Accession number :
- edsair.doi.dedup.....6c26dfaf96af412f445c1267940ef3b3