Variable effects of heart rate on phasic and regional left ventricular muscle blood flow in anaesthetized dogs

Tachycardia to 240 beats/min in anaesthetized dogs increases coronary blood flow while flow in the left ventricular wall remains homogeneous. An arteriovenous fistula causes subendocardial ischaemia at 120 beats/min but pacing to 180 to 210 beats/min increases subendocardial blood flow by increasing diastolic coronary driving pressure per minute.