Model based analysis of sleep disordered breathing in congestive heart failure

We employed a computational model of the respiratory control system to examine which of several factors, in isolation and in combination, can contribute to or explain the development of Cheyne-Stokes breathing (CSB). Our approach uses a graphical method for stability analysis similar, in concept, to the phase plane. The results from the computer simulations indicate that a postulated three-fold increase in the chemosensitivity of the central chemoreflex (CCR) loop may, by itself, explain development of CSB. By contrast, a similar increase in the chemosensitivity of the peripheral chemoreflex (PCR) loop cannot, by itself, account for CSB. The analysis reveals that the system is more readily destabilized by increasing the gain of only one chemoreflex loop than by a combined increase in gain of both loops. Reduction in the cardiac output or cardiomegaly decreases the size of the stability region. We conclude that development of CSB is the result of a complex interaction between CCR and PCR loops which may, in turn, interact with decreased cardiac output and cardiomegaly.