RESUMO
Cheyne-Stokes respiration (CSR) may trigger ventricular arrhythmia in patients with heart failure with reduced ejection fraction (HFrEF) and central sleep apnoea (CSA). This study determined the prevalence and predictors of a high nocturnal ventricular arrhythmia burden in patients with HFrEF and CSA (with and without CSR) and to evaluate the temporal association between CSR and the ventricular arrhythmia burden. This cross-sectional ancillary analysis included 239 participants from the SERVE-HF major sub-study who had HFrEF and CSA, and nocturnal ECG from polysomnography. CSR was stratified in ≥20% and <20% of total recording time (TRT). High burden of ventricular arrhythmia was defined as >30 premature ventricular complexes (PVCs) per hour of TRT. A sub-analysis was performed to evaluate the temporal association between CSR and ventricular arrhythmias in sleep stage N2. High ventricular arrhythmia burden was observed in 44% of patients. In multivariate logistic regression analysis, male sex, lower systolic blood pressure, non-use of antiarrhythmic medication and CSR ≥20% were significantly associated with PVCs >30·h-1 (OR 5.49, 95% CI 1.51-19.91, p=0.010; OR 0.98, 95% CI 0.97-1.00, p=0.017; OR 5.02, 95% CI 1.51-19.91, p=0.001; and OR 2.22, 95% CI 1.22-4.05, p=0.009; respectively). PVCs occurred more frequently during sleep phases with versus without CSR (median (interquartile range): 64.6 (24.8-145.7) versus 34.6 (4.8-75.2)·h-1 N2 sleep; p=0.006). Further mechanistic studies and arrhythmia analysis of major randomised trials evaluating the effect of treating CSR on ventricular arrhythmia burden and arrhythmia-related outcomes are warranted to understand how these data match with the results of the parent SERVE-HF study.
RESUMO
BACKGROUND: Automatic positive airway pressure (APAP) devices are increasingly being used in patients with obstructive sleep apnea. Some APAP devices present an unstable behavior when subjected to some events or artifacts. The aims were to develop a bench model capable of reproducing real flow, snoring, and obstructive patterns and to compare the response of APAP devices based on flow and snoring with other devices using, in addition, the forced oscillation technique (FOT). METHODS: The bench model subjected APAP devices to apneas with and without obstruction, obstructive hypopneas with and without snoring, periods of flow limitation, and artifacts such as leaks and mouth expiration. RESULTS: Almost all the devices increased the pressure when subjected to apneas with obstruction, but at different rates. The time required by each device to reach 10 cm H(2)O ranged from 2.5 to 13 min. In the presence of apneas without obstruction, all the devices based on flow and snoring increased the pressure at the same rate as during apneas with obstruction. However, the devices using FOT did not modify the pressure. Four devices did not modify the pressure in the presence of obstructive hypopneas, and all but one device increased the pressure in the presence of snoring. Mask leaks had little effect on the response of the devices, but four devices increased the pressure during mouth expiration artifacts. CONCLUSIONS: When, in addition to the flow and snoring signals, the measurement of the upper airway resistance is included, the accuracy of the event detection algorithms is improved.