From the Guidelines
Sick sinus syndrome should be treated with a permanent pacemaker, specifically atrial-based pacing (AAI or DDD), to regulate the heart rate and reduce the risk of atrial fibrillation and stroke, as evidenced by the 2013 ESC guidelines on cardiac pacing and cardiac resynchronization therapy 1. The diagnosis of sick sinus syndrome is typically made through electrocardiogram (ECG), Holter monitoring, event recording, or electrophysiology studies, and is characterized by abnormally slow heart rates, pauses in the heart rhythm, or alternating slow and fast rhythms.
- Symptoms of sick sinus syndrome include:
- Fatigue
- Dizziness
- Fainting
- Shortness of breath
- Chest pain
- Palpitations
- The condition is more common in older adults and can be caused by age-related fibrosis of the conduction system, coronary artery disease, heart failure, or previous cardiac surgery.
- Medications that slow heart rate, such as beta-blockers, calcium channel blockers, and certain antiarrhythmics, should be avoided or discontinued in these patients as they can worsen symptoms, as noted in the 2001 European Heart Journal guidelines on management of syncope 1.
- For patients with associated atrial fibrillation, anticoagulation therapy may be necessary to prevent stroke, and the use of rate-adaptive pacing may be warranted to minimize exertion-related lightheadedness or syncope.
- The DANish Multicenter Randomized Trial on Single Lead Atrial PACing vs. Dual Chamber Pacing in Sick Sinus Syndrome (DANPACE) study showed that AAIR pacing is associated with a higher incidence of paroxysmal AF than DDDR pacing, supporting the use of dual-chamber pacing in these patients 1.
From the Research
Diagnosis of Sick Sinus Syndrome (SSS)
- The diagnosis of SSS is made by electrocardiographic identification of the arrhythmia in conjunction with the presence of symptoms 2
- Electrocardiography (ECG) is the primary diagnostic tool, and may show severe sinus bradycardia, sinus arrest, or sinoatrial block 3
- If ECG does not yield a diagnosis, additional tests such as inpatient telemetry monitoring, outpatient Holter monitoring, event monitoring, or loop monitoring may be used 2
- Electrophysiologic studies may also be used, but are not routinely needed 2
Treatment of Sick Sinus Syndrome (SSS)
- Treatment of SSS includes removing extrinsic factors, when possible, and pacemaker placement 2
- Pacemakers do not reduce mortality, but they can decrease symptoms and improve quality of life 2
- Cardiac pacing is the most powerful therapy, with physiologic pacing (atrial or dual-chamber) shown to be superior to ventricular pacing 3
- Oral theophylline may also be beneficial for the treatment of patients with SSS, decreasing the frequency and duration of sinus pauses and improving symptoms 4
- Dual-chamber rate-responsive pacemaker therapy has been shown to decrease the incidence of syncope and heart failure in patients with SSS 5