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Figure 2 Calculation of Blood Flow in the Left Circumflex Artery of a Dog With a Moderate Stenosis
In the upper part of the screen, aortic pressure (Pa) and distal coronary pressure (Pd) are shown. The blue curve in the lower part of the screen shows intracoronary temperature. On the left, blood temperature at steady-state hyperemia (Tb) is set to 0. Next, infusion of saline is started at a rate of 20 ml/min (yellow arrow). During steady-state saline infusion, temperature in the coronary artery (T) decreases by 0.85°C. Next, the sensor is pulled back to measure blood temperature to the tip of the infusion catheter (Ti) (*), which is 5.57°C below initial blood temperature. Therefore, calculated coronary blood flow = 20 x (5.57/0.85) x 1.08 = 147 ml/min (true flow measured by the flow probe was 154 ml/min in this case).
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