Chronotropic and Inotropic Components of Cardiac Reflexes in Cats

The relationship between chronotropic and inotropic components of cardiac reflexes were studied in cats using intravenous blood injections, occlusion of the abdominal aorta, pressing on eyeballs (Aschner maneuver), and occlusion of the carotid arteries. Inotropic reactions were characterized by the contractility index DP×HR/MSAP. Different reflexes were shown to be characterized by different ratio of chronotropic and inotropic components, in addition, heart rate and contractility were often altered in opposite directions.