Myocardial oxygen consumption (MVÌ‡O2) and coronary blood flow (CBF) distribution were studied in 21 isolated, metabolically supported dog hearts. Measurements of MVÌ‡O2 and CBF distribution were carried out in three different experimental conditions : empty beating heart (EBH), ventricular fibrillation (VF) and high potassium-induced cardiac arrest (CA). MVÌ‡2 was approximately the same in EBH and VF (4.09 + 0.77 and 4.28 + 0.68 ml O2 min-1 100 g-1 respectively), and significantly lower in the group with CA (2.40 +0.18 ml O2 min-1 100 g-1, P < 0.05). Total CBF showed no significant differences among the three groups (84 + 7 ml/min in EBH; 78 + 7 ml/min in VF and 83 + 7 ml/min in CA). Subendocardial CBF per unit of tissue mass was significantly lower in hearts with VF (0.43 + 0.01 ml min-1 g-1, P < 0.05) when tested against the other two groups of experiments (0.69 + 0.03 ml min-1 g-1 in EBH and 0.65 + 0.04 ml min-1 g-1 in CA). This was also reflected in the endo/epi ratio, that was significantly lower in VF (1.41 + 0.07, P < 0.05) with respect to the other two groups (2 + 0.09 in EBH and 2.21 + 0.07 in CA).
ASJC Scopus subject areas
- Physiology (medical)