What causes sudden atrial fibrillation while sleeping?
Patient: My husband is 34 with Af. He was in ICU for 2 days then to main floor for 1 then released. He is under supervision  and currently taken Ritmaland PP meds. He was fine for 2 weeks with no fibulation but all the sudden every night this week he is waking up in AF about 3:30 am , It last any where from 30 mins to an hour.  What is causing this and why at night when he is sleeping. Doctor: when lying in supine position venous return to heart will increase and work load increase so if heart not working well Means atria get dilated leading to AF to the patient.