Caution For Those With Atrial Fibrillation Related to Sleep Apnea

July 24, 2008 7:12 AM CT

There is important news just out for those with atrial fibrillation.

We already know that there is a greater risk of atrial fibrillation among those with obstructive sleep apnea than even among those with other cardiovascular diseases. And afib patients with untreated sleep apnea are more likely to revert back into afib after electrical cardioversion than other afib patients without sleep apnea.

We also know that by not getting enough oxygen to the body, afib can lead to heart and valve diseases, sleep apnea, and chronic fatigue.

Many who have atrial fibrillation also have obstructive sleep apnea. Thus this latest study, just published in the Journal of the American College of Cardiology, is quite eye-opening. It found that patients who have night time heart attacks are very likely to have obstructive sleep apnea and that the sleep apnea may be the cause of the heart attacks.

Generally, most heart attacks happen between 6 AM and noon, but this study found that obstructive sleep apnea may lead to plaque rupture, clots, and heart attacks, shifting the normal timing of heart attacks. Of patients in the study having heart attacks between midnight and 6 AM, 91% had sleep apnea, suggesting that sleep apnea may trigger a heart attack.

Dr Virend Somers, of Mayo Clinic, senior author of the study, said, “Patients with sleep apnea experience significant physiologic stress at night—low oxygen levels activate the sympathetic nervous system, which thus causes a significant rise in blood pressure, and the patient is therefore exposed to a significant level of simultaneous problems. In addition, patients with sleep apnea show nighttime changes on their ECG that suggest the heart is not getting enough blood. I would say that it is likely that sleep apnea could be causing these nighttime MIs [heart attacks], but we have not proven that it actually is the cause. But I would still advise anyone who has had an MI during the night to get checked out for sleep apnea.

He added: “We need more studies to investigate whether sleep apnea therapy such as continuous positive airway pressure can prevent nocturnal cardiac events.

If you have afib and think you may have obstructive sleep apnea, it may be time to get a sleep study to find out for sure. And if you do have sleep apnea, treatment could possibly save your life.

MI at Night May Be Caused By Sleep Apnea