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Sick sinus syndrome: Treatment

Munther K Homoud, MD
Section Editor
Leonard I Ganz, MD, FHRS, FACC
Deputy Editor
Brian C Downey, MD, FACC


Sick sinus syndrome (SSS) is characterized by dysfunction of the sinoatrial (SA) node that is often secondary to senescence of the SA node and surrounding atrial myocardium. The term "sick sinus syndrome" was first used in 1967 to describe the sluggish return of SA nodal activity in some patients following electrical cardioversion, and was later applied to a clinical syndrome characterized by chronic SA node dysfunction, a sluggish or absent SA nodal pacemaker after electrical cardioversion, frequently depressed escape pacemakers, and/or atrioventricular (AV) nodal conduction disturbances [1-3]. These abnormalities can result in profound sinus bradycardia, sinus pauses, sinus arrest, SA nodal exit block, and inappropriate responses to physiological demands during exercise or stress. SSS can also be accompanied by AV nodal conduction disturbances and by paroxysmal atrial tachycardia as part of the tachycardia-bradycardia syndrome. (See "Sick sinus syndrome: Epidemiology, etiology, and natural history".)

The initial clues to the diagnosis of SSS are often clinical, as patients may present with symptoms of lightheadedness, presyncope, syncope, dyspnea on exertion, angina, and/or palpitations. A routine electrocardiogram (ECG) may provide further information in such patients. However, the symptoms are nonspecific and the ECG changes may not be diagnostic. Therefore, it is important to establish a symptom-rhythm correlation, something which is often achieved through noninvasive monitoring and, in rare cases, electrophysiologic studies. The diagnostic evaluation should also include a search for reversible causes of SA nodal depression, such as drugs (eg, beta blockers, calcium channel blockers, digoxin), ischemia, and autonomic imbalance, prior to initiation of treatment. (See "Sick sinus syndrome: Epidemiology, etiology, and natural history" and "Sick sinus syndrome: Clinical manifestations, diagnosis, and evaluation".)

Treatment of SSS is directed at symptoms. Control of symptomatic SSS usually involves the implantation of a pacemaker. Medications are rarely helpful, and most cases require permanent pacing for effective treatment. (See "Permanent cardiac pacing: Overview of devices and indications".)

The treatment of SSS will be reviewed here. The clinical manifestations, causes, and natural history of SSS; the noninvasive and electrophysiologic evaluation of SSS; and the appropriate timing of referral to a specialist are discussed in detail separately. (See "Sick sinus syndrome: Epidemiology, etiology, and natural history" and "Sick sinus syndrome: Clinical manifestations, diagnosis, and evaluation" and "Arrhythmia management for the primary care clinician", section on 'Referral to a specialist'.)


Treatment of SSS is directed at ameliorating symptoms, which may include lightheadedness, presyncope, syncope, and, less often, dyspnea on exertion or worsening angina. In addition, patients with tachycardia-bradycardia syndrome may present with palpitations and other symptoms associated with a rapid heart rate. However, it is not uncommon for patients to develop clinical manifestations of SSS insidiously. While some individuals present with frank syncope, patients more commonly report progressive development of the symptoms described above and often equate this with natural "aging."


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Literature review current through: Sep 2016. | This topic last updated: May 4, 2016.
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