Progress in cardiovascular diseases
-
Prog Cardiovasc Dis · Jan 2009
ReviewCardiovascular, inflammatory, and metabolic consequences of sleep deprivation.
That insufficient sleep is associated with poor attention and performance deficits is becoming widely recognized. Fewer people are aware that chronic sleep complaints in epidemiologic studies have also been associated with an increase in overall mortality and morbidity. This article summarizes findings of known effects of insufficient sleep on cardiovascular risk factors including blood pressure, glucose metabolism, hormonal regulation, and inflammation with particular emphasis on experimental sleep loss, using models of total and partial sleep deprivation, in healthy individuals who normally sleep in the range of 7 to 8 hours and have no sleep disorders. These studies show that insufficient sleep alters established cardiovascular risk factors in a direction that is known to increase the risk of cardiac morbidity.
-
Prog Cardiovasc Dis · Jan 2009
ReviewSleep-disordered breathing: autonomic mechanisms and arrhythmias.
Obstructive sleep apnea (OSA) is present in at least 2% to 4% of the general population. Central sleep apnea (CSA), though less common, is highly prevalent in patients with heart failure. Both forms of sleep apnea exert strong modulatory effects on the autonomic nervous system at night through a number of mechanisms including central respiratory-cardiac coupling in the brainstem, chemoreflex stimulation, baroreflexes, and reflexes relating to lung inflation. ⋯ Although sleep is normally a time when parasympathetic modulation of the heart predominates and myocardial electrical stability is enhanced, OSA and CSA disturb this quiescence, creating an autonomic profile in which both profound vagal activity leading to bradyarrhythmias, and sympatho-excitation favoring ventricular ectopy are observed. The resulting tendency toward cardiac arrhythmia may directly contribute to sudden cardiac death and premature mortality in patients with sleep apnea. Therapy consists largely of treatment with continuous positive airway pressure, which has been shown to improve autonomic profile and reduce nocturnal arrhythmias.
-
Prog Cardiovasc Dis · Jan 2009
ReviewEpidemiology, risk factors, and consequences of obstructive sleep apnea and short sleep duration.
We will review the epidemiology, risk factors, and consequences of obstructive sleep apnea (OSA) and short/long sleep duration. Obstructive sleep apnea is a disease characterized by recurrent upper airway obstruction during sleep. Obstructive sleep apnea is common, with moderate to severe disease present in approximately 9% of middle aged men and 4% of women. ⋯ Obstructive sleep apnea negatively impacts quality of life and is also associated with a number of adverse safety and health consequences including cardiovascular disease and motor vehicle crashes. Short habitual sleep duration can result in excessive daytime sleepiness and reduced neurocognitive function. Sleep loss may have long-term health consequences and may lead to premature death, cardiovascular disease, and the development of diabetes.
-
Sleep plays a large role in patients with heart failure. In normal subjects, sleep is usually in a supine position with reduced sympathetic drive, elevated vagal tone and as such a relatively lower cardiac output and minute ventilation, allowing for recuperation. Patients with heart failure may not experience the same degree of autonomic activity change and the supine position may place a large strain on the pulmonary system. ⋯ Treatment of CSA-CSR is best undertaken by treating the underlying cardiac condition which may include with medications, pacemakers, transplantation or continuous positive airway pressure (CPAP). In such patients CPAP exerts unique effects to assist cardiac function and reduce pulmonary edema. Whether CPAP improves survival in this heart failure population remains to be determined.