Sleep and Cardiovascular Disorders

Sleep is essential for life and for physical, mental and emotional well being. Sleep must be of good quantity and quality. There is a close association between sleep and cardiovascular system. Cardiac functions in sleep are under control of autonomic nervous system activity, which in turn is dictated by brain states. NREM sleep is associated with relative cardiac and autonomic stability. There is also a functional co-ordinated activity between cardiac and respiratory variables. However in REM sleep there is cardiac bound sympathetic and parasympathetic activity which results in significant surges and pauses in heart rhythm. It is expected that these changes have a potential to affect cardiac function particularly coronary blood flow and cardiac stability. Sleep is not a protected state in subjects suffering from cardiac and respiratory disease.