Sick Sinus Syndrome

Obtain a 12-lead ECG during symptoms when possible and determine whether sinus bradycardia, sinus pauses, sinus arrest, junctional escape rhythm, ectopic atrial rhythm, atrial tachyarrhythmia with post-conversion pauses, or atrioventricular block is present. Awake sinus bradycardia, sinus pauses, junctional rhythm, and ectopic atrial rhythm with rates below 50 beats/min are ECG patterns that should prompt assessment for sinus node dysfunction, but the management decision depends on symptom-rhythm correlation rather than a rate threshold alone. jacc+1jacc2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm SocietyAHA Journals2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society

Treat an acutely symptomatic bradyarrhythmia as a time-sensitive rhythm problem while pursuing the cause. In a stable outpatient or inpatient evaluation, do not infer sick sinus syndrome from fatigue, dizziness, presyncope, or syncope unless the symptom occurs with documented bradycardia or chronotropic incompetence; symptoms occurring without bradycardia do not benefit from permanent pacing. AHA Journals+2AHA Journals2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm SocietyAHA JournalsACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities | CirculationPubMedSinus Node Dysfunction - StatPearls - NCBI Bookshelf

Sinus node dysfunction is usually an age-associated, progressive fibrotic disorder involving sinus nodal tissue and surrounding atrial myocardium. The same atrial substrate commonly coexists with atrial arrhythmias, producing tachycardia-bradycardia syndrome; therefore, review all rhythm strips for atrial fibrillation or other atrial tachyarrhythmias, especially when pauses occur after tachyarrhythmia termination. jacc+2jacc2018 ACC/AHA/HRS Guideline on the Evaluation and ...jaccSick Sinus Syndrome: Synopsis∗PubMedSinus node dysfunction: current understanding and future directions - PMC

Start with a focused history, examination, and 12-lead ECG. Ask whether symptoms occur at rest, with exertion, after conversion from palpitations, during sleep, or after a medication dose. Review prior ECGs, telemetry, wearable or device tracings, and hospitalization records for sinus pauses, marked bradycardia, atrial fibrillation, or alternating atrial tachyarrhythmia and bradycardia. PubMed+1PubMedSinus Node Dysfunction - StatPearls - NCBI BookshelfPubMedAmbulatory ECG Monitoring - StatPearls - NCBI Bookshelf

Use ambulatory ECG monitoring when the initial ECG does not capture a diagnostic event. A 24- to 48-hour ambulatory ECG is appropriate when symptoms occur daily; use longer-term monitoring when episodes are less frequent. The required endpoint is a recording that demonstrates whether symptoms coincide with bradycardia, a pause without an adequate escape rhythm, or an atrial tachyarrhythmia-related pause. PubMed+1PubMedTrends in research on sick sinus syndrome: A bibliometric analysis from 2000 to 2022 - PMCPubMedAmbulatory ECG Monitoring - StatPearls - NCBI Bookshelf

Order exercise electrocardiographic testing when exertional fatigue, exertional presyncope, or exercise-related symptoms raise concern for chronotropic incompetence. Exercise testing is also reasonable for exercise-related symptoms suspicious for bradycardia or conduction disease and for 2:1 atrioventricular block of uncertain level. jaccjacc2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society

Reserve electrophysiology study for exceptional unresolved cases after noninvasive assessment, not as a routine confirmation test. In a younger patient with persistent symptomatic bradycardia, an unrevealing standard evaluation, or features suggesting inherited conduction disease, electrophysiology study and consideration of genetic testing can be useful; reported related genes include HCN4, SCN5A, and MYH6. jacc+2jacc2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm SocietyPubMedSick sinus syndrome (Concept Id: C0037052) - MedGen - NCBIPubMedA novel association between sinus node dysfunction and an SCN5A variant presenting as persistent symptomatic bradycardia in a young adult

Perform a medication reconciliation that includes beta-blockers and calcium-channel blockers, and determine whether each agent is essential. Withdraw or reduce nonessential rate-slowing therapy when clinically safe, then reassess symptoms and rhythm. Symptomatic bradycardia due to nonessential drug therapy is not an indication for permanent pacing. AHA Journals+2AHA JournalsACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities | CirculationPubMedSinus Node Dysfunction - StatPearls - NCBI BookshelfPubMedSick Sinus Syndrome - StatPearls - NCBI Bookshelf - NIH

For necessary therapy, distinguish a reversible adverse effect from an unavoidable tradeoff. Permanent pacing is indicated when symptomatic sinus bradycardia results from drug therapy required for another medical condition; this scenario is particularly relevant in tachycardia-bradycardia syndrome when beta-blocker therapy needed for atrial fibrillation suppresses sinus-node function and produces prolonged pauses after tachyarrhythmia cessation. AHA Journals+1AHA JournalsACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities | CirculationPubMedSick Sinus Syndrome - StatPearls - NCBI Bookshelf - NIH

Check and correct electrolyte and metabolic abnormalities, and assess for uncontrolled sleep apnea. Sleep-related sinus bradycardia or transient pauses should not trigger pacemaker implantation unless another pacing indication exists. jacc+2jacc2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm SocietyPubMedSinus Node Dysfunction - StatPearls - NCBI BookshelfPubMedSick Sinus Syndrome - StatPearls - NCBI Bookshelf - NIH

Intrinsic disease is most likely when symptomatic bradycardia or chronotropic failure persists after reversible factors are corrected, particularly in an older patient with the degenerative fibrotic substrate that also predisposes to atrial arrhythmias. In younger patients, consider postoperative sinus-node injury after congenital heart surgery and an inherited or secondary cardiovascular/systemic cause when the phenotype is disproportionate to age. jacc+3jacc2018 ACC/AHA/HRS Guideline on the Evaluation and ...jaccSick Sinus Syndrome: Synopsis∗PubMedPharmacologic Approach to Sinoatrial Node DysfunctionPubMedA novel association between sinus node dysfunction and an SCN5A variant presenting as persistent symptomatic bradycardia in a young adult

Recommend permanent pacemaker implantation for sinus node dysfunction with documented symptomatic bradycardia, including frequent sinus pauses that produce symptoms. Implantation is also indicated for symptomatic chronotropic incompetence and for symptomatic sinus bradycardia resulting from required drug therapy. AHA Journals+1AHA JournalsACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities | CirculationPubMedSick Sinus Syndrome - StatPearls - NCBI Bookshelf - NIH

Do not implant a pacemaker in asymptomatic sinus node dysfunction, when symptom episodes are documented in the absence of bradycardia or chronotropic incompetence, for sleep-related pauses alone, or for asymptomatic bradycardia attributable to physiologic parasympathetic tone. These exclusions are critical because sinus node dysfunction is generally not life-threatening and pacing benefit is primarily symptom relief rather than treatment of an ECG abnormality. jacc+2jacc2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm SocietyAHA Journals2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm SocietyAHA JournalsACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities | Circulation

Discuss procedural and longitudinal tradeoffs before implantation. Permanent pacemaker implantation carries an estimated 3% to 7% complication range, and transvenous systems create long-term lead and device-management implications. The expected benefit should therefore be explicit: reduced bradycardia-related symptoms and improved quality of life, not assured survival benefit. AHA Journals+1AHA Journals2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm SocietyAHA JournalsACC/AHA Guidelines for Implantation of Cardiac ...

In tachycardia-bradycardia syndrome, pacing may permit necessary rate-slowing therapy when atrial arrhythmia management otherwise produces symptomatic pauses. Continue to identify and manage the atrial arrhythmia rather than treating the pacing system as treatment for the atrial substrate itself. jacc+1jacc2018 ACC/AHA/HRS Guideline on the Evaluation and ...PubMedSick Sinus Syndrome - StatPearls - NCBI Bookshelf - NIH

At follow-up, reassess syncope, presyncope, exertional intolerance, fatigue, palpitations, and medication exposure against interval ECG or device data. If symptoms recur without bradycardia, investigate non-bradyarrhythmic causes rather than escalating pacing therapy. AHA Journals+1AHA Journals2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm SocietyAHA JournalsACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities | Circulation

Review monitoring and pacemaker diagnostics for atrial fibrillation or other atrial tachyarrhythmias because degenerative atrial fibrosis links sinus node dysfunction with tachy-brady syndrome. In patients with atrial fibrillation, assess ischemic stroke risk using CHA2DS2-VASc as recommended for atrial fibrillation risk stratification. jacc+1jacc2018 ACC/AHA/HRS Guideline on the Evaluation and ...PubMedSinus node dysfunction and stroke risk: a systematic review and meta-analysis

Remain alert for atrioventricular conduction disease. Some patients paced for sinus node dysfunction develop heart block, consistent with more diffuse conduction-system fibrosis; new atrioventricular block on chronic stable nodal-blocking therapy may not resolve after medication withdrawal and warrants continued surveillance. jacc+1jacc2018 ACC/AHA/HRS Guideline on the Evaluation and ...AHA Journals2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society