Relationships between oxygen consumption rate ( MVO
), blood flow ( F ), and heart rates ( HR ) in cardiac tissue. (A.) Plot of blood flow against oxygen consumption rate. (B.) Plot of heart rate against oxygen consumption rate. Experimental data are obtained from the following sources: ○, Zhang et al. ; ◁, Zhang et al. ; ◇, Gong et al. ; △, Ochiai et al. ; ▽, Gong et al. ; □, Bache et al. . The relationship between JATPase, the ATP hydrolysis rate, and MVO2 is predicted by the computer model. The solid lines represent the best fits to the data: G = 0.2146 MVO2 + 0.0093 with R-squared value (R2) = 0.9414 (in Figure A) and HR = 11.415 MVO2 + 96.95 with R2 = 0.6892 (in Figure B). The vertical dashed lines mark baseline (JATPase = 0.36 mmol s-1 (l cell)-1) and high MVO2 (JATPase = 1.2 mmol s-1 (l cell)-1). JATPase is expressed in units of mmol s-1 (l cell)-1, G in units of ml min-1 (g tissue)-1, and HR in units of beats min-1.