Varying patterns of hyperpnea during Cheyne-Stokes respiration in heart failure: Implication for cardiac function

Abstract

In heart failure (HF) patients with Cheyne Stokes respiration (CSR), we have noted 2 patterns of hyperpnea: positive, in which end-expiratory lung volume (EELV) is above functional residual capacity (FRC), and negative, in which EELV falls below FRC [Fig1.a,b]. The latter implies an increase in expiratory intrathoracic pressure, from activation of expiratory muscles. We hypothesized that this may be a compensatory mechanism to support stroke volume (SV) when it is very low, as manifest by longer CSR cycle duration and lung-to-finger circulation time (LFCT) than the positive pattern. Patients with HF underwent polysomnography and were divided into those with a negative or positive pattern. Brain natriuretic peptide (BNP) was measured. In each CSR episode, duration of the apnea-hyperpnea cycle and LFCT were measured. Of 15 patients (14men, 67yr) with CSR, 4 had a negative pattern. There was no difference in age or apnea-hypopnea index between the groups. Patients with a negative pattern had longer cycle lengths (78±14 vs 54±10s, p=0.03) and higher BNP (994±745 vs 92±80pmol/l, p=0.01) than those with a positive pattern. LFCT didn9t differ. HF patients with a negative CSR pattern have longer cycle length and higher BNP suggestive of worse cardiac function. The negative pattern generates greater positive expiratory pressure that might cause a self-resuscitation effect to maintain SV by “squeezing” the heart.