A patient with symptomatic sick sinus syndrome (bradycardia-tachycardia syndrome) requires pacing. Which pacing mode is preferred to reduce the risk of pacemaker syndrome and atrial fibrillation?

• A DDD pacing with rate response (DDDR) — maintains AV synchrony; preferred over VVI in SSS without AV block ✓
• B VVI pacing — simple, single lead, adequate for all bradyarrhythmias
• C AOO pacing — asynchronous atrial pacing without demand function
• D VOO pacing — safe first-line choice in all patients with SSS

Explanation

In sick sinus syndrome without significant AV node disease, DDD pacing (dual-chamber, rate-responsive) is preferred because it maintains physiological AV synchrony, preserving cardiac output and preventing pacemaker syndrome (retrograde VA conduction causing symptoms in VVI). Long-term, DDD/DDDR pacing reduces the incidence of atrial fibrillation compared to VVI pacing (demonstrated in CTOPP, MOST, DANISH trials). AAI pacing (atrial only) is an alternative if AV node is intact, but DDD provides backup ventricular pacing. VVI is acceptable only in chronic AF where atrial pacing is not useful.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

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Written and medically reviewed by the StethoPrep medical team.