Sick sinus syndrome: Treatment
- Munther K Homoud, MD
Munther K Homoud, MD
- Associate Professor of Medicine
- Tufts University School of Medicine
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."
- Ferrer MI. The sick sinus syndrome in atrial disease. JAMA 1968; 206:645.
- Lown B. Electrical reversion of cardiac arrhythmias. Br Heart J 1967; 29:469.
- Ferrer MI. The Sick Sinus Syndrome, Futura Press, New York 1974.
- Birnie D, Williams K, Guo A, et al. Reasons for escalating pacemaker implants. Am J Cardiol 2006; 98:93.
- Epstein AE, DiMarco JP, Ellenbogen KA, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons. Circulation 2008; 117:e350.
- Härtel G, Talvensaari T. Treatment of sinoatrial syndrome with permanent cardiac pacing in 90 patients. Acta Med Scand 1975; 198:341.
- Albin G, Hayes DL, Holmes DR Jr. Sinus node dysfunction in pediatric and young adult patients: treatment by implantation of a permanent pacemaker in 39 cases. Mayo Clin Proc 1985; 60:667.
- Skagen K, Fischer Hansen J. The long-term prognosis for patients with sinoatrial block treated with permanent pacemaker. Acta Med Scand 1976; 199:13.
- Lichstein E, Aithal H, Jonas S, et al. Natural history of severe sinus bradycardia discovered by 24 hour Holter monitoring. Pacing Clin Electrophysiol 1982; 5:185.
- Flaker G, Greenspon A, Tardiff B, et al. Death in patients with permanent pacemakers for sick sinus syndrome. Am Heart J 2003; 146:887.
- Sra JS, Jazayeri MR, Avitall B, et al. Comparison of cardiac pacing with drug therapy in the treatment of neurocardiogenic (vasovagal) syncope with bradycardia or asystole. N Engl J Med 1993; 328:1085.
- Healey JS, Toff WD, Lamas GA, et al. Cardiovascular outcomes with atrial-based pacing compared with ventricular pacing: meta-analysis of randomized trials, using individual patient data. Circulation 2006; 114:11.
- Lamas GA, Lee KL, Sweeney MO, et al. Ventricular pacing or dual-chamber pacing for sinus-node dysfunction. N Engl J Med 2002; 346:1854.
- Connolly SJ, Kerr CR, Gent M, et al. Effects of physiologic pacing versus ventricular pacing on the risk of stroke and death due to cardiovascular causes. Canadian Trial of Physiologic Pacing Investigators. N Engl J Med 2000; 342:1385.
- Kerr CR, Connolly SJ, Abdollah H, et al. Canadian Trial of Physiological Pacing: Effects of physiological pacing during long-term follow-up. Circulation 2004; 109:357.
- Andersen HR, Thuesen L, Bagger JP, et al. Prospective randomised trial of atrial versus ventricular pacing in sick-sinus syndrome. Lancet 1994; 344:1523.
- Andersen HR, Nielsen JC, Thomsen PE, et al. Long-term follow-up of patients from a randomised trial of atrial versus ventricular pacing for sick-sinus syndrome. Lancet 1997; 350:1210.
- Nielsen JC, Andersen HR, Thomsen PE, et al. Heart failure and echocardiographic changes during long-term follow-up of patients with sick sinus syndrome randomized to single-chamber atrial or ventricular pacing. Circulation 1998; 97:987.
- Hellkamp AS, Lee KL, Sweeney MO, et al. Treatment crossovers did not affect randomized treatment comparisons in the Mode Selection Trial (MOST). J Am Coll Cardiol 2006; 47:2260.
- Rosenqvist M, Obel IW. Atrial pacing and the risk for AV block: is there a time for change in attitude? Pacing Clin Electrophysiol 1989; 12:97.
- Andersen HR, Nielsen JC, Thomsen PE, et al. Atrioventricular conduction during long-term follow-up of patients with sick sinus syndrome. Circulation 1998; 98:1315.
- Kristensen L, Nielsen JC, Pedersen AK, et al. AV block and changes in pacing mode during long-term follow-up of 399 consecutive patients with sick sinus syndrome treated with an AAI/AAIR pacemaker. Pacing Clin Electrophysiol 2001; 24:358.
- Brandt J, Anderson H, Fåhraeus T, Schüller H. Natural history of sinus node disease treated with atrial pacing in 213 patients: implications for selection of stimulation mode. J Am Coll Cardiol 1992; 20:633.
- Nielsen JC, Thomsen PE, Højberg S, et al. A comparison of single-lead atrial pacing with dual-chamber pacing in sick sinus syndrome. Eur Heart J 2011; 32:686.
- Schwaab B, Kindermann M, Schätzer-Klotz D, et al. AAIR versus DDDR pacing in the bradycardia tachycardia syndrome: a prospective, randomized, double-blind, crossover trial. Pacing Clin Electrophysiol 2001; 24:1585.
- Sweeney MO, Prinzen FW. A new paradigm for physiologic ventricular pacing. J Am Coll Cardiol 2006; 47:282.
- Doshi RN, Daoud EG, Fellows C, et al. Left ventricular-based cardiac stimulation post AV nodal ablation evaluation (the PAVE study). J Cardiovasc Electrophysiol 2005; 16:1160.
- Sweeney MO, Hellkamp AS. Heart failure during cardiac pacing. Circulation 2006; 113:2082.
- Curtis AB, Worley SJ, Adamson PB, et al. Biventricular pacing for atrioventricular block and systolic dysfunction. N Engl J Med 2013; 368:1585.
- Rubenstein JJ, Schulman CL, Yurchak PM, DeSanctis RW. Clinical spectrum of the sick sinus syndrome. Circulation 1972; 46:5.
- Wan SH, Lee GS, Toh CC. The sick sinus syndrome. A study of 15 cases. Br Heart J 1972; 34:942.
- Sigurd B, Jensen G, Meibom J, Sandoe E. Adams-Stokes syndrome caused by sinoatrial block. Br Heart J 1973; 35:1002.
- Alboni P, Menozzi C, Brignole M, et al. Effects of permanent pacemaker and oral theophylline in sick sinus syndrome the THEOPACE study: a randomized controlled trial. Circulation 1997; 96:260.
- Hocini M, Sanders P, Deisenhofer I, et al. Reverse remodeling of sinus node function after catheter ablation of atrial fibrillation in patients with prolonged sinus pauses. Circulation 2003; 108:1172.
- January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2014; 64:e1.
- Corea F, Tambasco N. Cardiac pacing: atrial fibrillation may go unrecognised. Lancet Neurol 2005; 4:265.
- Healey JS, Connolly SJ, Gold MR, et al. Subclinical atrial fibrillation and the risk of stroke. N Engl J Med 2012; 366:120.
- Indications for pacemaker placement in SSS
- Pacemaker modalities
- Physiologic pacing
- - Meta-analysis and clinical trials
- - AAI versus DDD pacemakers
- Pacing and ventricular synchrony
- - Risk for ventricular pacing-induced dyssynchrony
- - Treatment of dyssynchrony
- Additional considerations
- - Pharmacologic therapy
- - Anticoagulation
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS