Cardiorespiratory Synchronism in Humans

Cardiorespiratory synchronism manifests itself (generally at respiratory rates higher than the corresponding baseline heart rates) when the heart adjusts itself to the respiratory rhythm and eventually beats at rate equal to the rate of respiration. Its characteristic parameters are the width of the synchronization range, the time needed for its development (measured from the onset of tachypnea), and the difference between the baseline heart rate and the lower and upper limits of the synchronization range. These parameters were determined for 5- to 65-year-old subjects.