A tangled affair: pacemaker malfunction and syncope in a child due to Twiddler's syndrome.

Manipulation of an implanted pacemaker by the patient is a rare cause of malfunction, especially in children. We describe a child who inadvertently rotated his pacemaker under the skin, knotting the leads and dislodging them from the heart, leading to syncope and heart block. Our experience with this case underscores the need to consider this diagnosis in children as well as in adults if this problem is to be averted.