Background Beta1-receptor antagonists (BBs) are commonly administered in the treatment of cardiovascular disease (CVD). The reported benefits of BB use in CVD patients with concomitant obstructive sleep apnea (OSA) may be limited by their impact on apnea-induced bradycardias. Therefore the aim of the study was to test the influence of BBs on periapneic heart rate (HR) fluctuations in hypertensive patients with newly-detected and untreated OSA. Methods We studied 88 hypertensive patients (56 on BBs and 32 BB naive) with newly-diagnosed moderate-to-severe OSA who were free of major pulmonary comorbidities and did not require antiarrhythmic therapy. ECGs recorded during sleep were investigated for heart rate (HR) responses to apneas allowing to compare extreme HR accelerations and decelerations between the groups. Results Average sleep-time HR were comparable in BB-naive (BB−) and BB-treated (BB+) patients. Direct comparisons showed that HR decelerations were also similar in the two subgroups (53.8 ±9.6 vs. 54.4 ±7.8 bpm; P=0.78, for BB− and BB+, respectively) however, BBs blunted the OSA-induced HR accelerations (82.3 ±12.2 vs. 74.3±10.0; P=0.003). After adjusting for baseline HR and magnitude of desaturations, HR decelerations were more evident in BB-naive group whereas tachycardic responses remained blunted in the BB+ group. The incidence of ectopies and conduction abnormalities were comparable across two groups. Conclusions Beta-blockers do not potentiate apnea-induced HR decelerations, attenuate apnea-induced increases in heart rate and do not influence incidence of ectopies and conduction abnormalities in patients with hypertension and moderate-to-severe, untreated OSA.

The paper presents a new approach to detection of apnea/hypopnea events, in the presence of artifacts and breathing irregularities, from a single-channel airflow record. The proposed algorithm, based on a robust envelope detector, identifies segments of signal affected by a high amplitude modulation corresponding to apnea/hypopnea events. It is shown that a robust airflow envelope-free of breathing artifacts-improves effectiveness of the diagnostic process and allows one to localize the beginning and the end of each episode more accurately. The performance of the proposed approach, evaluated on 30 overnight polysomnographic recordings, was assessed using diagnostic measures such as accuracy, sensitivity, specificity, and Cohen's coefficient of agreement; the achieved levels were equal to 95%, 90%, 96%, and 0.82, respectively. The results suggest that the algorithm may be implemented successfully in portable monitoring devices, as well as in software-packages used in sleep laboratories for automated evaluation of sleep apnea/hypopnea syndrome.

BackgroundObstructive sleep apnea (OSA) is associated with elevated risk of cardiovascular events. The early stages of vascular complications can be visualized by means of ultrasound. Intima-media thickness (IMT) correlates with the presence of risk factors of cardiovascular diseases such as hypertension, diabetes, tobacco smoking, or hyperlipidemia. However, little is known whether OSA itself may be the cause of IMT thickening.MethodsThe study group was composed of 28 patients (6 women, 22 men; mean age = 53.8 years, mean BMI = 27.1 kg/m2, mean AHI = 22.4/h) with OSA who had no comorbidities. The control group consisted of 28 healthy subjects (6 women, 22 men; mean age = 53.9 years; mean BMI = 27.5 kg/m2). In both groups IMT was assessed in common carotid arteries with the use of ultrasonography. Additionally, in patients with OSA, pulse wave velocity, echocardiography, 24-h automated blood pressure monitoring, clinical signs and symptoms, and blood tests were performed to investigate possible correlations with IMT.ResultsMedian IMT was 0.41 mm in OSA patients and 0.46 mm in the control group (p = 0.087). Echocardiography revealed left ventricle hypertrophy in 21 %, systolic disorders in 8 %, and diastolic disorders in 57 % of the patients. In a large majority of patients, pulse wave velocity was found to be normal. IMT correlated with age (r = 0.446, p = 0.017), total cholesterol (r = 0.518, p = 0.005), daytime systolic blood pressure (r = 0.422, p = 0.025), pulse pressure 24 h and daytime (r = 0.424, p = 0.027 and r = 0.449, p = 0.019), early mitral flow/atrial mitral flow (E/A) (r = −0.429, p = 0.023), and posterior wall diameter (PWD) (r = 0.417, p = 0.270).ConclusionIn a relatively nonobese group of patients, no significant differences were found in the intima-media thickness between OSA patients without concomitant cardiovascular diseases and healthy controls. This may lead to the conclusion that IMT does not reflect increased risk of cardiovascular events in patients with isolated OSA.

Wstęp: Spośród chorób układu oddechowego przewlekła obturacyjna choroba płuc jest jedną z najczęstszych przyczyn zachorowalności, hospitalizacji i inwalidztwa. Jej przewlekły, postępujący charakter oraz okresowe zaostrzenia mają istotny niekorzystny wpływ na jakość życia chorych na POChP i na rokowanie. W ostatnich latach znacznie wzrosła rola rehabilitacji w leczeniu chorych na POChP. Stała się ona skutecznym i coraz bardziej rozpowszechnionym narzędziem w leczeniu zarówno choroby podstawowej, jak i jej powikłań. W niniejszej pracy przedstawiono 3-tygodniowy program rehabilitacji chorych na POChP i jego wpływ na jakość życia tych pacjentów. Materiał i metody: Analizą objęto 132 chorych na POChP; do badania zakwalifikowano 70 osób (53%). Program rehabilitacji trwał 15 dni treningowych. Skuteczność rehabilitacji oceniano na podstawie kwestionariusza Szpitala Św. Jerzego, badania spirometrycznego i próby wysiłkowej. Wyniki: Stwierdzono znamienną poprawę jakości życia u chorych oraz wydłużenie czasu trwania testu wysiłkowego, zarówno bezpośrednio po zakończeniu rehabilitacji, jak i 3 miesiące później. Nie stwierdzono istotnej różnicy parametrów ocenianych na podstawie badania spirometrycznego. Wnioski: Trzytygodniowy program rehabilitacji chorych na POChP poprawił ich wydolność fizyczną i jakość życia, a poprawa ta utrzymywała się przynajmniej przez 3 miesiące.

The paper discusses the analysis of the respiratory events of sleep apnea patients. The analysis was carried out on the basis of the patient's airflow. As a result of the conducted analysis we proposed an algorithm which establishes an individual respiratory pattern for each subject. The algorithm could be implemented in the measurementcontrol system which manages the prosthetic device applying positive airway pressure. Its implementation could allow for a precise prediction of an upcoming apnea episode which in consequence prevents airway from collapsing.