Respiratory heart rate relationship in the decerebrate cat.

The respiratory heart rate relationship was examined in 10 decerebrate cats. The relationship appears to be a multi-part phenomenon consisting of (1) the inspiratory acceleration of the heart rate, which is well known, plus (2) the tendency toward small numbered relationships of integers between heart and respiration, as for example 2:1 to 5:1 heart rate to respiratory rate rather than complete randomness in the multiples of cardiac intervals in the respiratory cycle, and (3) registry of the heart and respiratory cycles upon each other in conformity to definitions of linear autonomous systems. So the phenomenon can be attributable to the influence of respiration upon the heart, the influence of the heart upon respiration, resulting in the mutual influence of both in supplying the physiological needs of perfusion of the periphery revealing higher integrations which an autonomous system would require.