Sleep is essential for life and for physical, mental and emotional well being. Sleep has a close relation to cardiovascular system scientifically and emotionally.
There are several risk factors for hypertension,diabetes,coronary heart disease etc, but Sleep disorders as a risk factor has not been highlighted.
NORMAL SLEEP AND CARDIOVASCULAR CHANGES
In Non Rapid Eye Movement (NREM) sleep there is generalized decrement of mean heart rate and blood pressure with marked autonomic stability with parasympathetic dominance.( Stable blood pressure and overall cardiac homeostasis giving an opportunity for metabolic restoration). However there is a risk for further ischemia in patients who suffer from severe coronary disease.
During transition from NREM to (Rapid eye Movement) REM sleep there is heart rate acceleration
pauses in heart rhythm or even frank asystole and shifts in posture resulting in autonomic activation. With aging these shifts are more frequent.
At the initiation of REM sleep there is increased excitability resulting in profound bursts in sympathetic activity.These bursts trigger intermittent increase in heart rate and blood pressure. Breathing patterns become irregular and can result in oxygen desaturations. REM sleep therefore has the capacity to disturb cardiorespiratory homeostasis. However cardiovascular homeostasis must be maintained in sleep and this is achieved by close co-ordination of respiratory and cardiovascular systems.
ABNORMAL SLEEP AND CARDIOVASCULAR DISORDERS.
Sleep is generally beneficial and protective but not in subjects suffering from respiratory and cardiac disease as it can precipitate cardiac arrythmias, myocardial ischemia, breathing disorders and even death.
SLEEP DISORDERS :
Obstructive sleep apnea (OSA), Central sleep apnea (CSA), Chronic sleep deprivation ( CSD ), Nightmares are some of the sleep disorders with adverse effects on the cardiovascular system. OSA is a common disorder but is usually not recognized in clinical practice. The disorder is characterized by repeated pharyngeal collapse pharynx in sleep resulting in cyclical hypoxemia. Sympathetic stimulation coupled with release of stress hormones and endothelin impose a significant burden on the cardiovascular and metabolic systems. OSA is a risk factor for the development of hypertension, ischemic heart disease, strokes, type 2 diabetes mellitus,dementia and others. Habitual snoring (often loud) and excessive daytime sleepiness are the two prominent symptoms of the disorder. The other nocturnal symptoms witnessed apneas, choking, dyspnea (can be mistaken for dyspnea of cardiac origin) restlessness manifested by frequent change of posture, nocturia due to release of atrial natrureticpeptide gastroesophageal reflux, diaphoresis and drooling. Some subjects may just complain of insomnia (patient unable to continue sleep due to repeated arousals) and may compel a physician to prescribe an hypnotic. Sedatives, hypnotics and antianxiety medicines are often prescribed in cardiology practice. Such drugs increase the hypotonia of pharyngeal muscles and therefore should be avoided in patients of OSA. Alcohol is used as sleeping aid by some patients and it also carries similar risk. It is not uncommon to observe patients have choked themselves in sleep after consuming such medications/ alcohol before retiring to bed. It is also important to note that OSA patients are often REM sleep deprived. Chronic REM sleep deprivation results in anxiety, excessive eating and hypersexuality. Excessive eating promotes obesity which in turn aggravates sleep apnea. It is therefore necessary to treat sleep apnea in obese individuals to achieve optimal body weight.
Daytime symptoms of OSA includes sleepiness, fatigue, morning headaches, poor concentration, decreased attention, depression, decreased dexterity and personality changes. Subjects of OSA often exhibit mood swings behaviour and may seek psychiatrist’s opinion. Although obesity is risk factor for development of OSA it is not uncommon to observe OSA in low and normal body weight subjects due to anatomical factors (narrow upper airway). Polysomnography is the gold standard to diagnose OSA.
The apneic hyponeic episodes of OSA have the capability of disrupting myocardial perfusion even in individuals without cardiac disease. The resultant effects are manifested by nocturnal myocardial ischemia, arrythmias and hypertension. A greater prevalence of cardiovascular complications is seen throughtout the spectrum of sleep disordered breathing which consists of snoring, upper airway resistance syndrome and obstructive sleep apnea.
Sleep apnea and hypertension
OSA is an established risk factor for hypertension. In fact it is one of the common and important causes for reversible hypertension.
The chronic usage of continuous positive airway pressure (CPAP) in patients with hypertension and obstructive sleep apnea results in reduction of hypertension both while awake and during sleep..
Sleep disordered breathing in pregnancy may have adverse effects both on the mother and foetus( pregnancy induced hypertension and small for gestational age birth). It is interesting to note that approximately 28% of children born in India are of low birth weight and low birth weight is associated with elevated levels of glucocorticoid in later life. A story from womb to the tomb.
Cardiac medications and Sleep
Lipophilic beta-blockers pinidolol, propanolol and metoprolol increases the number of awakenings and period of wakefulness as compared to placebo and non-lipophilic betablockers like atenolol. Betablockers in general do cause daytime lethargy possibly due to sleep disruption. Melatonin is also depleted by beta-blockers. Beta-blockers and calcium channel blockers may provoke nightmares.
SLEEP DEPRIVATION AND CARDIOVASCULAR EVENTS
Chronic sleep deprivation (CSD) is associated with cardiovascular events by more than one mechanism.viz (1) Sleep deprivation induces or aggravates snoring by increasing muscular hypotonia and delaying contraction of the dilator muscles of pharynx. (2) By causing an autonomic imbalance. (3) CSD in young healthy volunteers has been reported to increase levels of proinflammatory cytokines decrease parasympathetic and increase sympathetic tone, increase blood pressure, increases cortisol levels as well as elevate insulin and blood glucose levels.
Coronary Artery Disease ( CAD ) and sleep apnea.
Several studies have suggested that there is a greater risk of CAD in sleep related breathing disorders. There is 20 fold risk of developing myocardial infarction in untreated OSA. It is therefore important to screen all patients of coronary artery disease for sleep apnea. Treatment of sleep apnea is rewarding in multiple ways viz good quality of sleep, daytime alertness ,normal physical activity which helps in reducing body weight, good cardiovascular function and better glycemic control. Continuous positive airway pressure( CPAP) is the widely accepted mode of treatment of OSA.
Diabetes is a cardiovascular disease There is a close association between OSA and insulin resistance. The nocturnal events in OSA ultimately culminate in cyclical hypoxia, cylclical hypertension release of catecholamines & stress hormones , insulin resistance and diabetes Recently we have reported favourable results in glycemic control in 4 patients of type 2 diabetes who had associated obstructive sleep apnea with regular usage of CPAP. The beneficial metabolic effects of CPAP has been discussed recently and has been documented. There is a close association between diabetes, hypertension, ischemic heart disease, sleep disorders particularly sleep apnea.
Sleep Apnea and atrial fibrillation
Sleep apnea and atrial fibrillation frequently coexist. OSA has been implicated in the recurrence of atrial fibrillation..
OSA and Congestive Heart Failure (CHF)
Central Sleep apnea (CSA) is frequently observed in patients with congestive heart failure (CHF). The condition affects cardiovascular function adversely by causing tissue hypoxia , arousals from sleep and activation of the sympathetic nervous system. It also independently increases the risk of death.Studies have demonstrated beneficial effects of CPAP in CHF. Polysomnography is mandatory in all subjects of CHF.
In conclusion sleep disorders are common in clinical practice. It is time that we took cognizance of this in various cardiovascular disorders since patients usually do not attach much importance to sleep while narrating the history. Society in general has held the view that snoring is a sign of sound sleep. In literal terms sound sleep needs to be differentiated from healthy sleep. A close association exists between anatomical factors in the face, life style, sleep deprivation, sleep disorders, eating, obesity, hypertension, coronary heart disease, metabolic syndrome, cardiovascular morbidity and mortality. It is important to record sleep history in all patients suffering from hypertension, metabolic syndrome and coronary heart disease . Premature death in OSA patients is most often due to cardiovascular disorders. It is now accepted that treatment of OSA by CPAP is rewarding since it can prevent or improve hypertension, reduce abnormal elevations of inflammatory cytokines and adhesion molecules, reduce excessive sympathetic tone, avoid increased vascular oxidative stress, reverse coagulation abnormalities and reduce leptin levels. It is often argued sleep studies may not be economically feasible but given the benefits and properly placed before the patient in question would definitely improve compliance for the test.
Dr.S.Ramnathan Iyer, M.D.(Med) Dr.Revati.R.Iyer, M.S.( OBGY)
(9820143970) (9819598570)
There are several risk factors for hypertension,diabetes,coronary heart disease etc, but Sleep disorders as a risk factor has not been highlighted.
NORMAL SLEEP AND CARDIOVASCULAR CHANGES
In Non Rapid Eye Movement (NREM) sleep there is generalized decrement of mean heart rate and blood pressure with marked autonomic stability with parasympathetic dominance.( Stable blood pressure and overall cardiac homeostasis giving an opportunity for metabolic restoration). However there is a risk for further ischemia in patients who suffer from severe coronary disease.
During transition from NREM to (Rapid eye Movement) REM sleep there is heart rate acceleration
pauses in heart rhythm or even frank asystole and shifts in posture resulting in autonomic activation. With aging these shifts are more frequent.
At the initiation of REM sleep there is increased excitability resulting in profound bursts in sympathetic activity.These bursts trigger intermittent increase in heart rate and blood pressure. Breathing patterns become irregular and can result in oxygen desaturations. REM sleep therefore has the capacity to disturb cardiorespiratory homeostasis. However cardiovascular homeostasis must be maintained in sleep and this is achieved by close co-ordination of respiratory and cardiovascular systems.
ABNORMAL SLEEP AND CARDIOVASCULAR DISORDERS.
Sleep is generally beneficial and protective but not in subjects suffering from respiratory and cardiac disease as it can precipitate cardiac arrythmias, myocardial ischemia, breathing disorders and even death.
SLEEP DISORDERS :
Obstructive sleep apnea (OSA), Central sleep apnea (CSA), Chronic sleep deprivation ( CSD ), Nightmares are some of the sleep disorders with adverse effects on the cardiovascular system. OSA is a common disorder but is usually not recognized in clinical practice. The disorder is characterized by repeated pharyngeal collapse pharynx in sleep resulting in cyclical hypoxemia. Sympathetic stimulation coupled with release of stress hormones and endothelin impose a significant burden on the cardiovascular and metabolic systems. OSA is a risk factor for the development of hypertension, ischemic heart disease, strokes, type 2 diabetes mellitus,dementia and others. Habitual snoring (often loud) and excessive daytime sleepiness are the two prominent symptoms of the disorder. The other nocturnal symptoms witnessed apneas, choking, dyspnea (can be mistaken for dyspnea of cardiac origin) restlessness manifested by frequent change of posture, nocturia due to release of atrial natrureticpeptide gastroesophageal reflux, diaphoresis and drooling. Some subjects may just complain of insomnia (patient unable to continue sleep due to repeated arousals) and may compel a physician to prescribe an hypnotic. Sedatives, hypnotics and antianxiety medicines are often prescribed in cardiology practice. Such drugs increase the hypotonia of pharyngeal muscles and therefore should be avoided in patients of OSA. Alcohol is used as sleeping aid by some patients and it also carries similar risk. It is not uncommon to observe patients have choked themselves in sleep after consuming such medications/ alcohol before retiring to bed. It is also important to note that OSA patients are often REM sleep deprived. Chronic REM sleep deprivation results in anxiety, excessive eating and hypersexuality. Excessive eating promotes obesity which in turn aggravates sleep apnea. It is therefore necessary to treat sleep apnea in obese individuals to achieve optimal body weight.
Daytime symptoms of OSA includes sleepiness, fatigue, morning headaches, poor concentration, decreased attention, depression, decreased dexterity and personality changes. Subjects of OSA often exhibit mood swings behaviour and may seek psychiatrist’s opinion. Although obesity is risk factor for development of OSA it is not uncommon to observe OSA in low and normal body weight subjects due to anatomical factors (narrow upper airway). Polysomnography is the gold standard to diagnose OSA.
The apneic hyponeic episodes of OSA have the capability of disrupting myocardial perfusion even in individuals without cardiac disease. The resultant effects are manifested by nocturnal myocardial ischemia, arrythmias and hypertension. A greater prevalence of cardiovascular complications is seen throughtout the spectrum of sleep disordered breathing which consists of snoring, upper airway resistance syndrome and obstructive sleep apnea.
Sleep apnea and hypertension
OSA is an established risk factor for hypertension. In fact it is one of the common and important causes for reversible hypertension.
The chronic usage of continuous positive airway pressure (CPAP) in patients with hypertension and obstructive sleep apnea results in reduction of hypertension both while awake and during sleep..
Sleep disordered breathing in pregnancy may have adverse effects both on the mother and foetus( pregnancy induced hypertension and small for gestational age birth). It is interesting to note that approximately 28% of children born in India are of low birth weight and low birth weight is associated with elevated levels of glucocorticoid in later life. A story from womb to the tomb.
Cardiac medications and Sleep
Lipophilic beta-blockers pinidolol, propanolol and metoprolol increases the number of awakenings and period of wakefulness as compared to placebo and non-lipophilic betablockers like atenolol. Betablockers in general do cause daytime lethargy possibly due to sleep disruption. Melatonin is also depleted by beta-blockers. Beta-blockers and calcium channel blockers may provoke nightmares.
SLEEP DEPRIVATION AND CARDIOVASCULAR EVENTS
Chronic sleep deprivation (CSD) is associated with cardiovascular events by more than one mechanism.viz (1) Sleep deprivation induces or aggravates snoring by increasing muscular hypotonia and delaying contraction of the dilator muscles of pharynx. (2) By causing an autonomic imbalance. (3) CSD in young healthy volunteers has been reported to increase levels of proinflammatory cytokines decrease parasympathetic and increase sympathetic tone, increase blood pressure, increases cortisol levels as well as elevate insulin and blood glucose levels.
Coronary Artery Disease ( CAD ) and sleep apnea.
Several studies have suggested that there is a greater risk of CAD in sleep related breathing disorders. There is 20 fold risk of developing myocardial infarction in untreated OSA. It is therefore important to screen all patients of coronary artery disease for sleep apnea. Treatment of sleep apnea is rewarding in multiple ways viz good quality of sleep, daytime alertness ,normal physical activity which helps in reducing body weight, good cardiovascular function and better glycemic control. Continuous positive airway pressure( CPAP) is the widely accepted mode of treatment of OSA.
Diabetes is a cardiovascular disease There is a close association between OSA and insulin resistance. The nocturnal events in OSA ultimately culminate in cyclical hypoxia, cylclical hypertension release of catecholamines & stress hormones , insulin resistance and diabetes Recently we have reported favourable results in glycemic control in 4 patients of type 2 diabetes who had associated obstructive sleep apnea with regular usage of CPAP. The beneficial metabolic effects of CPAP has been discussed recently and has been documented. There is a close association between diabetes, hypertension, ischemic heart disease, sleep disorders particularly sleep apnea.
Sleep Apnea and atrial fibrillation
Sleep apnea and atrial fibrillation frequently coexist. OSA has been implicated in the recurrence of atrial fibrillation..
OSA and Congestive Heart Failure (CHF)
Central Sleep apnea (CSA) is frequently observed in patients with congestive heart failure (CHF). The condition affects cardiovascular function adversely by causing tissue hypoxia , arousals from sleep and activation of the sympathetic nervous system. It also independently increases the risk of death.Studies have demonstrated beneficial effects of CPAP in CHF. Polysomnography is mandatory in all subjects of CHF.
In conclusion sleep disorders are common in clinical practice. It is time that we took cognizance of this in various cardiovascular disorders since patients usually do not attach much importance to sleep while narrating the history. Society in general has held the view that snoring is a sign of sound sleep. In literal terms sound sleep needs to be differentiated from healthy sleep. A close association exists between anatomical factors in the face, life style, sleep deprivation, sleep disorders, eating, obesity, hypertension, coronary heart disease, metabolic syndrome, cardiovascular morbidity and mortality. It is important to record sleep history in all patients suffering from hypertension, metabolic syndrome and coronary heart disease . Premature death in OSA patients is most often due to cardiovascular disorders. It is now accepted that treatment of OSA by CPAP is rewarding since it can prevent or improve hypertension, reduce abnormal elevations of inflammatory cytokines and adhesion molecules, reduce excessive sympathetic tone, avoid increased vascular oxidative stress, reverse coagulation abnormalities and reduce leptin levels. It is often argued sleep studies may not be economically feasible but given the benefits and properly placed before the patient in question would definitely improve compliance for the test.
Dr.S.Ramnathan Iyer, M.D.(Med) Dr.Revati.R.Iyer, M.S.( OBGY)
(9820143970) (9819598570)
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