AAPA: Obstructive Sleep Apnea May Lurk Behind A-Fib

PHILADELPHIA, May 29 -- More than half of patients with atrial fibrillation are also likely to have obstructive sleep apnea, investigators suggested here.

A small study of patients treated for atrial fibrillation at the investigator's practice found that 19% had been diagnosed with obstructive sleep apnea and 66% were at high risk for the condition, said Jonathan Gietzen, M.S., P.A.-C., of Heart Rhythm Consultants in Portland, Ore., and colleagues.

Previous studies have suggested that the hypoxic effects of obstructive sleep apnea might lead to atrial fibrillation, which is the most common sustained cardiac arrhythmia and affects an estimated two million Americans, Gietzen said at the American Academy of Physician Assistants meeting.

"If such a relationship exists, by screening patients with known atrial fibrillation for obstructive sleep apnea, you have detected a treatable condition that may help decrease the recurrence of atrial fibrillation," the investigators said.

"Similarly, by screening patients with known obstructive sleep apnea for atrial fibrillation, you can rule out other such complications of both disorders, such as heart failure and stroke," they said.

The study used the Berlin Questionnaire and the Epworth Sleepiness Scale to assess the risk for obstructive sleep apnea in patients treated for atrial fibrillation at a specialty cardiology office from 2004 through May 2006. The instruments were mailed to the patients, who filled them out and mailed them back.

A total of 66 patients were categorized as high-risk for obstructive sleep apnea according to their answers on the 10-question Berlin assessment. Of these, 19 reported a previous diagnosis of obstructive sleep apnea. None of the patients identified as low-risk reported a previous diagnosis of sleep apnea.

Patients in the high-risk group tended to have a higher body mass index than those in the low-risk group (mean BMI=31.3 versus 27.8; P=0.0076).

And significantly more patients in the high-risk group had a history of hypertension (49 patients versus 7 in the low-risk group; P<0.0001).

Gender did not appear to be a factor, the investigators said, with males comprising 75% of the high-risk group and 65% of the low-risk group (P=0.15).

In addition, the Epworth Sleepiness Scale revealed that 57% of patients reported being excessively sleepy, a possible indicator of obstructive sleep apnea, the authors said.

"As the number of patients with atrial fibrillation continues to grow nationwide, it is of utmost importance to find the predisposing factors. With obesity and hypertension being risk factors for both atrial fibrillation and obstructive sleep apnea, it is of clinical importance to look at the possible connection between the two disorders," the authors said.

"With the evidence that such a high prevalence of patients with atrial fibrillation also exhibit signs of obstructive sleep apnea, they concluded, the presence of obstructive sleep apnea should be considered in all patients with atrial fibrillation," especially those who are obese and have hypertension.

"However, the association between obstructive sleep apnea and atrial fibrillation is controversial because of the multiple confounding variables that occur frequently in both," the investigators acknowledged.