← All quick references
ClearRounds Health · Cardiology · Quick Reference
Sinus Node Dysfunction / Sick Sinus Syndrome
PDF coming soon
Arrhythmias & DevicesIntermediateIn progressOne-page PDF
Bradycardia symptoms, pauses, chronotropic incompetence, medication causes, monitoring, and pacemaker referral.
Last reviewed
Pending initial clinical review
Sources / guidelines to verify
- 2018 ACC/AHA/HRS Bradycardia & Conduction Delay Guideline
Disclaimer: Educational reference only. Not a substitute for clinician judgment, local protocols, or current guideline review.
One-page reference
Draft content pending the site owner’s clinical review. Verify against the sources above and local protocol before clinical use.
1
What it is / why it matters
- Failure of SA-node automaticity → inappropriate bradycardia, pauses, chronotropic incompetence.
- Tachy-brady syndrome is a common variant.
2
Key diagnostic clues
- Fatigue, dizziness, syncope, exertional intolerance.
- Sinus bradycardia, sinus pauses/arrest, SA exit block — symptom-rhythm correlation is key.
3
Initial workup
- ECG + ambulatory monitor (correlate symptoms with rhythm); exercise test for chronotropic incompetence.
- TSH, medication review (beta-blocker/CCB/digoxin); exclude ischemia and sleep apnea.
4
Management framework
- Treat reversible causes (stop offending drugs, treat hypothyroidism/OSA).
- Pacemaker for symptomatic SND without a reversible cause.
- In tachy-brady, a pacer often enables AF rate control.
5
Red flags / escalate now
- Syncope, long pauses, or hemodynamic compromise → monitoring + EP/pacing evaluation.
6
Follow-up / monitoring
- Symptom-rhythm correlation; device follow-up after implant.
7
Clinic pearls
- Asymptomatic sinus bradycardia (athletes, sleep) needs no treatment.
- The diagnosis is symptom-rhythm correlation — not a heart-rate number.
Related quick references
Suggest an edit or request this reference
Spot something to improve, or want this one-pager prioritized? Send feedback to the ClearRounds Health team.
Share feedback →