Little is known about potential relationships between sleep apnea, plasma aldosterone and diastolic dysfunction which is a very frequent finding among patients requiring permanent cardiac pacing. Sleep apnea is often under diagnosed by clinical examination. Confirmation tests are expensive and access is limited. A specific algorithm available in a recent pacemaker allows assessing breathing variations using minute ventilation sensor, with a good agreement between the respiratory disturbance index and polysomnography results for the diagnosis of severe sleep apnea.