Obstructive sleep apnea: At least 10-second pause in respiration associated with ongoing ventilatory effort.

Hypopnea: There is a decrease, but not complete cessation of, ventilation.

      This is generally accompanied by an associated fall in oxygen saturation or arousal.

Obstructive sleep apnea (OSA) syndrome: Apnea-hypopnea index (the number of apneas and hypopneas

      per hour of sleep) is > 5 and there are symptoms of excessive daytime sleepiness.

Central sleep apnea: Apnea-hypopnea index is > 5 olup with no ventilatory effort.

Obstructive sleep apnea and arrhyhtmias

  Ventricular arrhythmias are generally observed during sleep and become more frequent during the apnea


  Ventricular arrhythmias are observed in 66% of patients with OSA.

  It has been reported that CPAP or tracheostomy decreses the frequency of arrhythmias in patients with OSA.

In obstructive sleep apnea, the following types of arrhythmias are seen with increased frequency

  Non-sustained ventricular tachycardia (VT)

  Frequent ventricular premature contractions (VPS)

  Second degree atrioventricular (AV) block

  Sinus arrest



  Circulation 2008;118:1080-1111.