Myocardial tissue pressure and blood flow during coronary sinus pressure modulation in anesthetized dogs
| Autor: | J. R. Rouleau, B. Cantin |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Physiology Diastole Hemodynamics Blood Pressure Electrocardiography Dogs Oxygen Consumption Physiology (medical) Internal medicine Coronary Circulation medicine Animals Anesthesia Systole Coronary sinus business.industry Myocardium Heart Blood flow Hydrogen-Ion Concentration Microspheres Blood pressure medicine.anatomical_structure Circulatory system cardiovascular system Cardiology Blood Gas Analysis business Artery |
| Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 73(5) |
| ISSN: | 8750-7587 |
| Popis: | To determine whether coronary sinus outflow pressure (Pcs) or intramyocardial tissue pressure (IMP) is the effective back pressure in the different layers of the left ventricular (LV) myocardium, we increased Pcs in 14 open-chest dogs under maximal coronary artery vasodilation. Circumflex arterial (flowmeter), LV total, and subendocardial and subepicardial (15-microns radioactive spheres) pressure-flow relationships (PFR) and IMP (needle-tip pressure transducers) were recorded during graded constriction of the artery at two diastolic Pcs levels (7 +/- 3 vs. 23 +/- 4 mmHg). At high Pcs, LV, aortic and diastolic circumflex arterial pressure, heart rate, myocardial oxygen consumption, and lactate extraction were unchanged; IMP in the subendocardium did not change (130/19 mmHg), whereas IMP in the subepicardium increased by 17 mmHg during systole and 10 mmHg during diastole (P < or = 0.001), independently of circumflex arterial pressure. Increasing Pcs did not change the slope of the PFR; however, coronary pressure at zero flow increased in the subepicardium (P < or = 0.008), whereas in the subendocardium it remained unchanged at 24 +/- 3 mmHg. Thus Pcs can regulate IMP independently of circumflex arterial pressure and consequently influence myocardial perfusion, especially in the subepicardial tissue layer of the LV. |
| Databáze: | OpenAIRE |
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