[Cardiovascular diseases].

Death from heart disease is sometimes observed at night. Life threatening arrhythmias or ischemic heart disease are suspected to be the cause of sudden death during night. Cheyne-Stokes respiration (CSR) is frequently observed in patients with chronic cardiac failure. CSR augments sympathetic nervous activity and reduces the quality of sleep. Sleep apnea or snoring is another stressful condition during sleep. During hyperventilatory phase of sleep apnea, the blood pressure, heart rate, end-systolic ventricular volume and vosomotor tone increases, and the periodic EEG arousal patterns are observed. Sleep apnea is suspected to be one of the risk factors of hypertension. The detection and early treatment of sleep apnea or Cheyne-Stokes respiration are required to reduce the mortality due to cardiac events during sleep.