Nocturnal Cardiac Arrhythmias in Heart Failure With Obstructive and Central Sleep Apnea.

BACKGROUND: Both OSA and central sleep apnea (CSA) may contribute to nocturnal cardiac arrhythmias (NCAs). Data are scarce regarding the prevalence of clinically important nocturnal atrial and ventricular arrythmias in patients with heart failure with reduced ejection fraction (HFrEF) and OSA or CSA. RESEARCH QUESTION: In a cohort of patients with HFrEF, how does the prevalence of NCA compare among those with OSA, CSA, and those with no to mild sleep apnea? Is the severity of OSA or CSA associated with atrial and ventricular NCAs? STUDY DESIGN AND METHODS: This cross-sectional analysis is an ancillary study of the Effect of Adaptive Servo Ventilation on Survival and Hospital Admissions in Heart Failure (ADVENT-HF) trial. We compared the prevalence of NCAs (excessive supraventricular ectopic activity [ESVEA], defined as premature atrial complexes ≥30/h or supraventricular tachycardia ≥ 20 beats); atrial fibrillation/flutter [AF]; and > 10 premature ventricular complexes [PVC/h]) on ECGs from polysomnograms of patients with HFrEF between those with OSA (apnea-hypopnea index [AHI ≥ 15 events/h]), those with CSA (AHI ≥ 15 events/h), and those with no to mild sleep apnea (AHI < 15 events/h [control]). RESULTS: The prevalence of ESVEA was higher in patients with OSA (n = 430) and CSA (n = 150) compared with control participants (n = 76): 0%, 9%, and 12%, respectively. The prevalence of AF in the control, OSA, and CSA groups was 9%, 17%, and 27%; the prevalence of > 10 PVC/h was 45%, 59%, and 63%. In multivariable regression analyses, premature atrial complexes/h was associated with OSA severity (obstructive AHI: 22.4% increase per 10 events/h [95% CI, 5.2-42.3; P = .009), although neither obstructive nor central AHI was associated with AF or > 10 PVC/h. INTERPRETATION: In patients with HFrEF, the prevalences of nocturnal ESVEA, AF, and PVC > 10/h were higher in those with OSA or CSA than in those without OSA or CSA, and OSA severity was related to the burden of nocturnal atrial ectopy. Severity of OSA or CSA was not significantly related to AF or > 10 PVC/h. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT01128816; URL: www. CLINICALTRIALS: gov.

[Treatment-Emergent Central Sleep Apnea - Detection and Treatment]. / Treatment-emergent zentrale Schlafapnoe erkennen und behandeln.

Treatment-Emergent Central Sleep Apnea - Detection and Treatment Abstract. In treatment-emergent central sleep apnea (TECSA), affected patients with obstructive sleep apnea newly develop central sleep apnea (AHI central ≥5/h) under therapy with positive pressure ventilation which cannot be explained by other causes. The pathophysiology of TECSA is incompletely understood. PaCO2 and the associated apnea threshold seem to play a central role. The incidence of TECSA varies (1.8-20%), and in about 2/3 of cases it is self-limiting in the course of the therapy. If persistence or new onset occurs later in the course of positive pressure therapy, a further evaluation (e.g., echocardiography, neurologic examination, medication history) is indicated. Effective treatment options include a change in ventilation therapy (adaptive servoventilation or bilevel ventilation with back-up frequency) or additional nocturnal oxygen supplementation; these options should be decided case by case.

Methodology for the nocturnal cardiac arrhythmia ancillary study of the ADVENT-HF trial in patients with heart failure with reduced ejection fraction and sleep-disordered breathing.

Background: Sleep disordered breathing (SDB) may trigger nocturnal cardiac arrhythmias (NCA) in patients with heart failure with reduced ejection fraction (HFrEF). The NCA ancillary study of the ADVENT-HF trial will test whether, in HFrEF-patients with SDB, peak-flow-triggered adaptive servo-ventilation (ASVpf) reduces NCA. To this end, accurate scoring of NCA from polysomnography (PSG) is required. Objective: To develop a method to detect NCA accurately from a single-lead electrocardiogram (ECG) recorded during PSG and assess inter-observer agreement for NCA detection. Methods: Quality assurance of ECG analysis included training of the investigators, development of standardized technical quality, guideline-conforming semi-automated NCA-scoring via Holter-ECG software and implementation of an arrhythmia adjudication committee. To assess inter-observer agreement, the ECG was analysed by two independent investigators and compared for agreement on premature ventricular complexes (PVC) /h, premature atrial complexes/h (PAC) as well as for other NCA in 62 patients from two centers of the ADVENT-HF trial. Results: The intraclass correlation coefficients for PVC/h and PAC/h were excellent: 0.99 (95%- confidence interval [CI]: 0.99-0.99) and 0.99 (95%-CI: 0.97-0.99), respectively. No clinically relevant difference in inter-observer classification of other NCA was found. The detection of non-sustained ventricular tachycardia (18% versus 19%) and atrial fibrillation (10% versus 11%) was similar between the two investigators. No sustained ventricular tachycardia was detected. Conclusion: These findings indicate that our methods are very reliable for scoring NCAs and are adequate to apply for the entire PSG data set of the ADVENT-HF trial.

Treatment-emergent central sleep apnea associated with non-positive airway pressure therapies in obstructive sleep apnea patients: A systematic review.

This systematic review summarizes the prevalence of treatment-emergent central sleep apnea (TECSA) occurring with therapies other than positive airway pressure (PAP) for the management of obstructive sleep apnea (OSA). We describe its natural course as well as the proposed underlying pathophysiological mechanisms and the clinical management of affected patients. A systematic search of PubMed, Embase, Web of science, and the Cochrane Library was performed until June 2020. Eighteen studies (n = 284 patients) were included. TECSA was observed in 31 patients with the use of four different medical devices (mandibular advancement device, hypoglossal nerve stimulation, tongue stabilizing device and nasal expiratory PAP) and after three different types of surgical treatments (tracheostomy, maxillofacial surgery and oro-nasal surgery). Due to the paucity of data available, it was not possible to establish a clear prevalence rate of TECSA for each alternative treatment. After the initiation of non-PAP treatments, a systematic reassessment of the treatment efficacy with follow-up sleep studies will be helpful to identify TECSA. A spontaneous resolution over time was described as well as a persistence of TECSA. In this case, treatment should focus on patients' specific underlying pathophysiology. Overall, the limited current literature suggests that this phenomenon is rare (<4%).

Efficacy of non-invasive intelligent volume assured pressure support (iVAPS) and pressure support ventilation (PSV) in clinical practice.

AIMS OF THE STUDY: Noninvasive ventilation (NIV) is a well-established treatment option for hypercapnic respiratory failure; however, the best mode of ventilation remains unknown. The aim of this retrospective study was to compare patients’ adherence to NIV using either pressure support ventilation (PSV) or intelligent volume-assured pressure support (iVAPS). PATIENTS AND METHODS: In this retrospective cohort study, we assessed in- and outpatients suffering from hypercapnic respiratory failure of various aetiologies (chronic obstructive pulmonary disease [COPD], obese COPD [body mass index >30 kg/m2], obesity hypoventilation syndrome and other diseases such as amyotrophic lateral sclerosis or interstitial lung disease) after NIV initiation with PSV or iVAPS. Adherence to treatment was compared between these modes using the Wilcoxon test. Within-group differences were tested using linear regression models. Mortality and emergency hospital readmission rates were modelled using Kaplan-Meier estimates and Cox proportional hazards models. RESULTS: Adherence to treatment was similar in both groups throughout the observation period – after 6 weeks: PSV 363 min/night (interquartile range [IQR] 200–448), iVAPS 369 min/night (IQR 310–468) (p = 0.619); after 1 year: PSV 423 (323–500), iVAPS 429 (298–475) (p = 0.901); at the last follow up: PSV 481 (395–586), iVAPS 426 (391–565) (p = 0.284). NIV reduced PaCO2 significantly compared with baseline at all follow-ups: PSV −1.29/−1.49/−1.49 kPa, iVAPS −1.47/−1.23/−1.24 kPa, p <0.001 each, PSV vs iVAPS: p = 0.250, 0.756 and 0.352, respectively. Median survival time (PSV 5.06 years, iVAPS median not reached; p = 0.800) and time to first readmission (PSV 3.6 years, iVAPS 7.33 years, p = 0.200) did not differ between groups. Obese COPD patients had a longer time to hospital readmission than lean COPD patients (3.8 vs 1.5 years, hazard ratio (HR) 0.39, 95% confidence interval [CI] 0.16–0. 74; p = 0.007). Good adherence (>4 h/night and >80% nightly usage) was associated with a lower mortality rate (HR 0.34, 95% CI 0.15–0.77; p = 0.010). CONCLUSION: In a real-world setting of a mixed population with hypercapnic respiratory failure, iVAPS and PSV seem to be similarly effective in improving gas exchange and demonstrate excellent adherence to treatment. A longer survival was noted in NIV-adherent patients. Randomised controlled studies are necessary to identify patients who might benefit more from hybrid ventilation modes.

Pulse Oximetry at the Wrist During Sleep: Performance, Challenges and Perspectives.

The state-of-the-art non-invasive measurement of peripheral oxygen saturation (SpO2) during sleep is mainly based on pulse oximetry at the fingertip. Although this approach is noninvasive, it can still be obtrusive and cumbersome to apply, in particular for ambulatory monitoring over several nights.We developed a wrist-worn reflectance pulse oximetry device which can be embedded in a watch, making it less obtrusive and easy to apply. This device was tested in an ongoing clinical study on 57 subjects (33 patients and 24 healthy volunteers) undergoing a full overnight polysomnography recording. The accuracy was evaluated against state-of-the-art fingertip SpO2 measurements.In the 54 subjects available for analysis we obtained an SpO2 accuracy (ARMS) of 3.4 % when automatically rejecting 17.7 % of signals due to low quality. When further excluding measurements suffering from insufficient contact of the watch with the skin an ARMS of 2.7 % was obtained while rejecting a total of 23.2 % measurements. These accuracies comply with the ISO standard and the FDA guidance for pulse oximeters.The present results are promising and pave the way for unobtrusive and continuous monitoring of SpO2 to screen for sleep disordered breathing. Nonetheless, contact pressure and venous blood have shown to adversely affect the SpO2 estimation and remain a challenge for wrist-based reflectance pulse oximetry.

Prevalence and Prediction of Obstructive Sleep Apnea Prior to Bariatric Surgery-Gender-Specific Performance of Four Sleep Questionnaires.

PURPOSE: Bariatric surgery (BS) is a treatment option for morbid obesity leading to substantial and sustained weight loss in adults. As obstructive sleep apnea (OSA) is highly prevalent in obese subjects and may increase the perioperative risk, screening for OSA is recommended prior to BS. In clinical routine, BS is performed more frequently in women. Therefore, we sought to assess the gender-specific performance of four sleep questionnaires (Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), STOPBang, and NoSAS) to predict moderate to severe OSA in the morbidly obese population. MATERIAL AND METHODS: We applied all four questionnaires to patients scheduled for BS with polygraphic OSA screening at our institution between 2012 and 2015 and performed gender-specific sensitivity analyses. RESULTS: We included 251 bariatric patients (76% female, median age 39 years, median BMI 42.0 kg/m2). OSA (AHI > 5/h; AHI > 15/h) was present in 43% (females 35%, males 68%; p < 0.001) and 21% (females 13%, males 45%; p < 0.001). STOPBang and NoSAS performed markedly better than ESS and FSS. With the exception of the ESS, all sleep questionnaires allowed better OSA prediction in women than in men. CONCLUSION: In obese patients scheduled for BS, a gender-specific difference was observed in the performance of the evaluated OSA screening questionnaires. This needs to be considered when these questionnaires are used. Our results underline the need for better gender-specific OSA screening algorithms in morbidly obese patients.

A 58-Year-Old Man With Position-Dependent Nocturnal Dyspnea.

CASE PRESENTATION: A 58-year-old man with idiopathic pulmonary fibrosis, who had received a right-sided single-lung transplant 2 years earlier, was referred to the sleep clinic for the assessment of nocturnal position-dependent episodes of dyspnea and frequent arousals when lying on his right side. There was no subjective worsening of daytime respiratory symptoms, but he complained of fatigue and unrefreshing sleep. His Epworth Sleepiness Scale score was 12/24. After lung transplantation he had a favorable course while receiving immunosuppression with prednisolone, everolimus, and mycophenolate mofetil. In addition, he had received diagnoses of stable coronary artery disease and moderate chronic kidney failure.

NIV by an interdisciplinary respiratory care team in severe respiratory failure in the emergency department limited to day time hours.

Non-invasive ventilatory support is frequently used in patients with severe respiratory failure (SRF), but is often limited to intensive care units (ICU). We hypothesized that an instantaneous short course of NIV (up to 2 h), limited to regular working hours as an additional therapy on the emergency department (ED) would be feasible and could improve patient´s dyspnoea measured by respiratory rate and Borg visual dyspnea scale. NIV was set up by an interdisciplinary respiratory care team. Outside these predefined hours NIV was performed in the ICU. This is an observational cohort study over 1 year in the ED in a non-university hospital. Fifty-one % of medical emergencies arrived during regular working hours (5475 of 10,718 patients). In total, 63 patients were treated with instantaneous NIV. Door to NIV in the ED was 56 (31-97) min, door to ICU outside regular working hours was 84 (57-166) min. Within 1 h of NIV, the respiratory rate decreased from 30/min (25-35) to 19/min (14-24, p < 0.001), the Borg dyspnoea scale improved from 7 (5-8) to 2 (0-3, p < 0.001). In hypercapnic patients, the blood-pH increased from 7.29 (7.24-7.33) to 7.35 (7.29-7.40) and the pCO2 dropped from 8.82 (8.13-10.15) to 7.45 (6.60-8.75) kPa. In patients with SRF of varying origin, instantaneous NIV in the ED during regular working hours was feasible in a non-university hospital setting, and rapidly and significantly alleviated dyspnoea and reduced respiratory rate. This approach proved to be useful as a bridge to the ICU as well as an efficient palliative dyspnoea treatment.

Transcutaneous versus blood carbon dioxide monitoring during acute noninvasive ventilation in the emergency department - a retrospective analysis.

QUESTIONS UNDER STUDY: Transcutaneous measurement of carbon dioxide (PtCO2) has been suggested as an alternative to invasively obtained PaCO2 for the monitoring of patients with hypercapnic respiratory failure during noninvasive ventilation (NIV). Current data on monitoring in hypoxaemic respiratory failure are scarce and show conflicting results in hypercapnic patients in the emergency department. METHODS AND SETTING: We performed a retrospective comparison of real-time PtCO2 (SenTec Digital Monitor) and arterial/venous carbon dioxide tension (PaCO2/PvCO2) measurements in patients with severe hypoxaemic and/or hypercapnic respiratory failure during NIV. Agreement between PtCO2 and PaCO2/PvCO2 was the primary endpoint. Bland-Altman analysis and linear regression were used. RESULTS: 102 patients had at least one matched measurement of PtCO2 and PaCO2/PvCO2. For patients with arterial blood gas analysis, the mean difference was 0.46 kPa at baseline (95% confidence interval [CI] 0.23 to 0.60, limits of agreement 95% CI -0.54 to 1.45) and 0.12 kPa after NIV (95% CI -0.04 to 0.29, limits of agreement 95% CI: -0.61 to 0.86). The linear regression analysis found a correlation R2 of 0.88 (p <0.001) at baseline and an R2 of 0.99 (p <0.001) after initiating NIV. For patients with venous blood gas analysis, the mean difference was 0.64 kPa at baseline (95% CI 0.04 to 1.24, limits of agreement 95% CI -0.72 to 2) and 0.80 kPa after NIV (95% CI 0.51 to 1.10, limits of agreement 95% CI 0.29 to 1.32), R2 0.78 (p <0.001) at baseline and R2 0.91 (p <0.001) after initiating NIV. A PaCO2/PvCO2 >8 kPa was associated with a lesser degree of agreement between the levels of PtCO2 and PaCO2/PvCO2 (p <0.001). CONCLUSION: Transcutaneous PCO2 monitoring shows a good concordance with PaCO2 and is a reliable, feasible, patient-friendly and safe alternative to repeated blood gas analysis for patients with severe hypoxaemic and/or hypercapnic respiratory failure receiving emergency NIV in the emergency department. An initial blood gas analysis to evaluate the respiratory and metabolic state and to rule out a significant discrepancy compared with the transcutaneous measurement is recommended.

A 43-Year-Old Man With Daytime Sleepiness and a Heart Murmur.

A 43-year-old man was referred to our tertiary sleep center for the initiation of sleep apnea treatment. A prior diagnostic overnight polysomnography (Fig 1) had revealed an apnea-hypopnea index (AHI) of 22/h of sleep. The apneas were predominantly central (central AHI, 18.2/h; obstructive AHI, 3.8/h), more pronounced in the supine position (AHI supine, 36.6/h; AHI nonsupine, 11/h) and during non-rapid eye movement (non-REM) sleep (REM, 15.8/h; non-REM, 23.5/h). A continuous positive airway pressure (CPAP) trial in an outpatient setting had failed, as the fixed CPAP of 11 cm H2O was not tolerated by the patient because of a feeling of lightheadedness when wearing the mask. At referral, the patient complained about falling asleep in front of the computer in the afternoons despite regular bedtimes and 7 to 8 h of sleep per night. His Epworth Sleepiness Scale score was 11. He had no significant past history including cardiopulmonary disease. He was not taking any medication but had noticed a slow decline in general physical performance in the last year, with dyspnea (New York Heart Association class I) after running distances of 1 to 2 km. He had never experienced syncope. His family history was unremarkable.