Delayed identification of high-degree atrioventricular block with prolonged asystole revealed after the removal of an implantable loop recorder owing to battery depletion.

There is a need for prolonged monitoring and close follow-up in cases of recurrent unexplained syncope and no diagnosis at the time of ILR explanation. Also, a second ILR should be implanted in cases with no clear diagnosis of syncope that probably has a cardiac origin.