Sick Sinus Syndrome
Sick Sinus Syndrome (sino-atrial node dysfunction):
This is a rare condition in which the main pacemaker of the heart, the sinus node, fails to work properly. The sinus node may not send electrical signals fast enough, may skip some signals, or may send too many signals resulting in slow and/or fast heartbeats. Many patients with this condition have a history of heart surgery such as closure of an atrial septal defect (ASD), Mustard-Senning operations for Transposition of the Great Arteries or a Fontan operation for single ventricle. Non-surgical causes include familial sinus node dysfunction, muscular dystrophy, complex congenital heart defects, inflammatory diseases, electrical disorders, hypothyroidism, medications and others.
Some patients may require implantation of a pacemaker if symptomatic or those with risk factors.