NEW YORK (Reuters Health) — Nearly two thirds of heart patients with implanted pacemakers have undiagnosed sleep apnea, a significantly higher prevalence than found in the general population, a study shows.“Because of the excessive prevalence of undiagnosed sleep apnea we found, it could be recommended that all patients referred for a pacemaker should first be screened for sleep apnea,” Dr. Patrick LDevy, at Grenoble University in France advises in a written statement. Even patients with pacemakers should be screened for sleep apnea, LDevy and colleagues advise, because untreated sleep apnea may further contribute to cardiovascular deterioration. The authors report their findings in Circulation: Journal of the American Heart Association.