Arnold tongues in human cardiorespiratory systems.
Arnold tongues are phase-locking regions in parameter space, originally studied in circle-map models of cardiac arrhythmias. They show where a periodic system responds by synchronizing to an external stimulus. Clinical studies of resting or anesthetized patients exhibit synchronization between heart-beats and respiration. Here we show that these results are successfully modeled by a circle-map, neatly combining the phenomena of respiratory sinus arrhythmia (RSA, where inspiration modulates heart-rate) and cardioventilatory coupling (CVC, where the heart is a pacemaker for respiration). Examination of the Arnold tongues reveals that while RSA can cause synchronization, the strongest mechanism for synchronization is CVC, so that the heart is acting as a pacemaker for respiration.
School of Mathematical and Computing Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
Mark
M
McGuinness
Young
Y
Hong
Duncan
D
Galletly
Peter
P
Larsen
D001146:Arrhythmia, Sinus / Q000503:physiopathology*; D001683:Biological Clocks; D002320:Cardiovascular Physiological Phenomena; D003198:Computer Simulation; D006339:Heart Rate; D006706:Homeostasis; D006801:Humans; D008955:Models, Cardiovascular; D015656:Respiratory Mechanics; D012143:Respiratory Physiological Phenomena; D014630:Vagus Nerve / Q000503:physiopathology