Nocturnal Continuous Positive Airway Pressure Improves Ventilatory Efficiency During Exercise in Patients With Chronic Heart Failure

Efeitos da pressão positiva contínua nas vias aéreas na insuficiência cardíaca crônica

“…The study was carried out with 10 (ten) patients from the HF Outpatient Clinic of HUCFF-UFRJ, with a diagnosis of chronic heart failure (CHF), with the following etiologies: hypertensive (50%), alcoholic (20%), idiopathic (20%) and peripartoum (10%), with a mean age of 54 ± 14 years, with a slight predominance of the male sex (6) in comparison to the female sex (4). The patients presented a mean BMI value of 21 ± 0.04 kg/m 2 .…”

Differential Timing of Arousals in Obstructive and Central Sleep Apnea in Patients with Heart Failure

“…22,24,25 On the other hand, several studies involving 17 to 26 HF patients with CSA in which CPAP lowered the AHI by 62% to 89% showed no effect on the ArI. 8,[26][27][28] In the largest multicenter trial to date, in which 258 HF patients with CSA were randomized to CPAP treatment or control, CPAP lowered the AHI by 55% after 3 months but did not lower the ArI or improve sleep structure. 15 Furthermore, there was no significant change in arousal frequency in the subgroup of 58 patients in whom CPAP reduced the AHI to < 15, nor in the 38 CPAP patients who underwent sleep studies 2 years after randomization, compared to the control group.…”

“…However, as described above, most studies in HF patients with CSA showed no significant reduction in the frequency of arousals in response to CPAP, despite a decrease in AHI. 8,[26][27][28] There are two possible reasons for this discrepancy. First, arousals may be classified as spontaneous or respiratory related.…”

Ventilatory support and pharmacological treatment of patients with central apnoea or hypoventilation during sleep

“…Another study documented significant reductions in overnight urinary norepinephrine excretion in patients with stable CHF and CSR while they were on nocturnal O 2 during a 4-week study [32]. In a recent study of 12-weeks' duration, nocturnal O 2 had no effect on either ventilatory efficiency during exercise (shown by the minute ventilation/CO 2 production slope) or left ventricular ejection fraction [33]. Increased afterload following O 2 was reported, however, this response was seen only with the acute administration of 100% O 2 [36,37].…”

“…All clinical studies showed that nasal O 2 significantly improves periodic breathing and virtually eliminates arterial desaturation [27][28][29][30][31][32][33]. In a recent randomised trial, benefit over standard medical care in left ventricular function and quality-of-life scores was demonstrated [34].…”