A Three Second Synopsis of AFP's "Sick Sinus Syndrome: A Review"

A synopsis of  "Sick Sinus Syndrome: A Review", MICHAEL SEMELKA, DO, and JEROME GERA, MD, Excela Health Latrobe Hospital, Latrobe, Pennsylvania, SAIF USMAN, MD, University of Missouri–Kansas City School of Medicine, Kansas City, Missouri
http://www.aafp.org/afp/2013/0515/p691.pdf
Am Fam Physician. 2013 May 15;87(10):691-696

     Sick sinus syndrome is a problem with the SA node appropriately pacing the heart to the patients physiological needs. It can cause arrhythmias such as sinus bradycardia, sinus pause/arrest, SA exit block, or alternating brady/tachyarrhythmias. Patients can develop atrial fibrillation or flutter, whuch may lead to an embolic stroke. They could also develop an AV block, There are intrinsic and extrinsic causes. The intrinsic causes include degenerative fibrosis or remodeling of the SA node, connective tissue diseases, hemochromatosis, sarcoidosis, atherosclerosis of the sinus node artery, and amyloidosis  Some of the extrinsic causes include hypothyroidism, hypokalemia, hyperkalemia, hypocalcemia, hypothermia, and medications such as beta blockers, calcium channel blockers, digoxin, and lithium. 

    The patient is often asymptomatic, but the disease is progressive. Symptoms incluse fainting spells, syncope, lightheadedness, palpitations, GI symptoms, CHF or stroke. These all arise from cerebral or end-organ hypoperfusion. sinus bradyarrhythmia, such as a SA pause of 3 seconds or more, SA  block, or sinus arrest, is required for diagnosis. Tachyarrhythmias are often seen as well, but not necessary for diagnosis. If you suspect sick sinus syndrome becaseu of the presentation but ypou cannot documetn the EKG findings, the patient may need prolonged cardiac monitoring. This can be done with a holter monitor,  inpatient telemetry monitoring, or an implantable loop monitor. 
 Treatment starts with correcting the extrinsic cuase, whether it is an electrolyt abnormality or a medicaiton reaction. Pacemakers are often implanted for symptomatic relief and improved quality of life. They do not, however, affect survival rates.