Thesis (M.S.)--University of Michigan, 1993.

Thesis (M.S.)--University of Michigan, 1986.

Thesis (M.S.)--University of Michigan, 1993.

Thesis (M.S.)--University of Michigan, 1986.

Thesis (M.S.)--University of Michigan, 1986.

INTRODUCTION: Research has consistently shown that sleep apnea is strongly associated with atrial fibrillation, with several lines of evidence demonstrating that this relationship is bidirectional and that each condition predisposes to and/or exacerbates the other. Many studies have suggested potential pathophysiologic mechanisms underlying this relationship, and that sleep apnea and atrial fibrillation share many of the same cardiovascular risk factors further implies that multiple pathways are likely involved in the mechanistic link between the two. Although the sleep apnea-atrial fibrillation relationship is quite established, numerous aspects of this association still require further study, such as the role of gender and the potential impact of positive airway pressure therapy. A deeper understanding of how these individual factors may be involved in the interrelationship between sleep apnea and atrial fibrillation has important clinical implications, such as for risk stratification and screening of patients. Thus, this study aims to further understand the different aspects and modulating factors of the sleep apnea-atrial fibrillation link, focusing on central sleep apnea as less is known about the central sleep apnea-atrial fibrillation relationship. METHODS: A total of 153 patients, originally seen at the cardiac electrophysiology clinic at Beth Israel Deaconess Medical Center and subsequently offered home sleep apnea testing, were included in this study. Several databases – home sleep apnea testing results, polysomnography reports, electrocardiogram reports and patient management systems – were used to obtain a variety of data on sleep pathology, high loop gain status, left ventricular ejection fraction and positive airway pressure therapy efficacy and compliance. Patients were considered to have central sleep apnea if home testing results demonstrated a central apnea-hypopnea index of 5 or greater and/or if the patient was documented as having high loop gain on polysomnography. Data were analyzed using the Statistical Package for Social Sciences software in order to examine how factors such as gender and therapy use may affect the sleep apnea-atrial fibrillation relationship, in a patient population with sleep pathology of at least moderate severity. RESULTS: Statistical analysis revealed significant sleep disturbances in the central sleep apnea patients compared to the non-central sleep apnea patients. Gender was found to be significantly associated with central sleep apnea, but not obstructive sleep apnea. When postmenopausal (age≥51) women were analyzed, very few patients met the study criteria for central sleep apnea, yet the majority were documented as having atrial fibrillation. As expected, positive airway pressure therapy was found to be beneficial for all users, but the common pattern of declining compliance to therapy was seen as adherence decreased over the course of three months. Of the select central sleep apnea patients who had sufficient data available, comparison of positive airway pressure therapy and cardiac data revealed possible benefits to cardiac health with compliant use of positive airway pressure therapy. CONCLUSION: Through examining different aspects of the sleep apnea-atrial fibrillation relationship, this study found promising evidence showing that gender and positive airway pressure therapy play important roles. Further studies, with larger sample sizes, need to be conducted in order to fully understand the specific impact of factors such as gender, gender and age and positive airway pressure therapy on the risks and outcomes in patients with sleep apnea and/or atrial fibrillation, and how these factors may change depending on the type of sleep apnea. Finally, these results further highlight the growing need for an effective collaborative care model between cardiologists and sleep medicine clinicians, as the management of patients with sleep apnea and atrial fibrillation requires an interdisciplinary approach in order to deliver the most optimal patient care.

Obstructive sleep apnea (OSA) is a common medical condition that occurs in a considerable percentage of the population. Substantial evidence shows that patients with OSA have an increased incidence of hypertension compared with individuals without OSA, and that OSA is a risk factor for the development of hypertension. It is established that OSA may be implicated in stroke and transient ischemic attacks. OSA is associated with coronary heart disease, heart failure, and cardiac arrhythmias. Pulmonary hypertension may be associated with OSA, especially in patients with pre-existing pulmonary disease. Although the exact cause that links OSA with cardiovascular disease is unknown, there is evidence that OSA is associated with a group of proinflammatory and prothrombotic factors that have been identified as important in the development of atherosclerosis. OSA is associated with increased daytime and nocturnal sympathetic activity. Autonomic abnormalities seen in patients with OSA include increased resting heart rate, decreased R-R interval variability, and increased blood pressure variability. Both atherosclerosis and OSA are associated with endothelial dysfunction, increased C-reactive protein, interleukin 6, fibrinogen, plasminogen activator inhibitor, and reduced fibrinolytic activity. OSA has been associated with enhanced platelet activity and aggregation. Leukocyte adhesion and accumulation on endothelial cells are common in both OSA and atherosclerosis. Clinicians should be aware that OSA may be a risk factor for the development of cardiovascular disease.

BACKGROUND:We tested the hypothesis that ventilatory drive in hypoxia and hypercapnia is inversely correlated with the number of hypopneas and obstructive apneas per hour of sleep (obstructive apnea hypopnea index, OAHI) in children.METHODS:Fifty children, 6 to 12 years of age were studied. Participants had an in-home unattended polysomnogram to compute the OAHI. We subsequently estimated ventilatory drive in normoxia, at two levels of isocapnic hypoxia, and at three levels of hyperoxic hypercapnia in each subject. Experiments were done during wakefulness, and the mouth occlusion pressure measured 0.1 seconds after inspiratory onset (P0.1) was measured in all conditions. The slope of the relation between P0.1 and the partial pressure of end-tidal O2 or CO2 (PETO2 and PETCO2) served as the index of hypoxic or hypercapnic ventilatory drive.RESULTS:Hypoxic ventilatory drive correlated inversely with OAHI (r = -0.31, P = 0.041), but the hypercapnic ventilatory drive did not (r = -0.19, P = 0.27). We also found that the resting PETCO2 was significantly and positively correlated with the OAHI, suggesting that high OAHI values were associated with resting CO2 retention.CONCLUSIONS:In awake children the OAHI correlates inversely with the hypoxic ventilatory drive and positively with the resting PETCO2. Whether or not diminished hypoxic drive or resting CO2 retention while awake can explain the severity of sleep-disordered breathing in this population is uncertain, but a reduced hypoxic ventilatory drive and resting CO2 retention are associated with sleep-disordered breathing in 6-12 year old children.

Los Trastornos Respiratorios del Sueño (TRS) son un grupo de enfermedades que afectan la funci ón respiratoria durante la noche, desde el ronquido primario a la apnea del sueño -la más grave de ellas-. Los niños que padecen apnea del sueño pueden desarrollar desde trastornos de crecimiento hasta de ficiencias cognitivas de largo plazo. Sin embargo, una vez que han sido diagnosticados, el tratamiento es efectivo en la mayor ía de los casos, mejorando su calidad de vida y evitando consecuencias en su desarrollo cognitivo. El gold-standard (mejor prueba cl í nica) para el diagn óstico de TRS es la polisomnografí a, que consiste en la recolecci ón de señales biom édicas durante el sueño. El problema es que este examen es invasivo, costoso y difí cil de practicar en niños pequeños. Por lo tanto existe la necesidad de una forma de prediagnosticar TRS, específi camente apnea para aumentar el n úmero de niños diagnosticados, y, como resultado, el n úmero de niños tratados. Para esto, el objetivo general planteado es prediagnosticar apnea obstructiva del sueño a partir de señales recogidas por polisomnografí a en niños menores de 15 años usando t écnicas de minerí a de datos. El resultado esperado de este trabajo es un algoritmo capaz de clasi ficar infantes, usando menos informaci ón que la polisomnografí a, en dos grupos: poblaci ón en riesgo de padecer apnea y poblaci ón fuera de riesgo (o muy bajo riesgo). El trabajo est á dividido en dos etapas, la primera de ellas son modelos basados en una señal, la segunda consta de modelos basados en m ás de una señal. Los resultados de la primera etapa muestran modelos de buena calidad aunque s ólo est án basados en una señal; algunos con sensibilidad y especi ficidad por sobre el 85% y podrí an sentar las bases de un modelo v álido de prediagn óstico. En la segunda etapa se identi ficaron, mediante t écnicas de reducci ón de informaci ón, las señales que tienen mayor poder predictivo para realizar el prediagn óstico, los modelos basados en estas señales alcanzaron hasta el 100% de precisi ón.

Introduction: Little is known about the impact of spousal involvement on continuous positive airway pressure (CPAP) adherence. The aim of this study was to determine whether spouse involvement affects adherence with CPAP therapy, and how this association varies with gender. Methods: 194 subjects recruited from Apnea Positive Pressure Long Term Efficacy Study (APPLES) completed the Dyadic Adjustment Scale (DAS). The majority of participants were Caucasian (83%), and males (73%), with mean age of 56 years, mean BMI of 31 kg/m2. & 62% had severe OSA. The DAS is a validated 32-item self-report instrument measuring dyadic consensus, satisfaction, cohesion, and affectional expression. A high score in the DAS is indicative of a person’s adjustment to the marriage. Additionally, questions related to spouse involvement with general health and CPAP use were asked. CPAP use was downloaded from the device and self-report, and compliance was defined as usage > 4 h per night. Results: There were no significant differences in overall marital quality between the compliant and noncompliant subjects. However, level of spousal involvement was associated with increased CPAP adherence at 6 months (p=0.01). After stratifying for gender these results were significant only among males (p=0.03). Three years after completing APPLES, level of spousal involvement was not associated with CPAP compliance even after gender stratification. Conclusion: Spousal involvement is important in determining CPAP compliance in males in the 1st 6 months after initiation of therapy but is not predictive of longer-term adherence. Involvement of the spouse should be considered an integral part of CPAP initiation procedures. Support: HL068060