Brady-tachy syndrome / sick sinus syndrome
Encounter flow
12/12 authoredCanonical 12-phase frame with authored status for this dossier.
Frame
Confirm SND with documented brady + symptom correlation; rule out reversible causes — drug, hypothyroid, OSA, electrolyte, ischemia, infiltrative (ACC/AHA/HRS 2018 Section 4.1 Kusumoto; ESC 2021 pacing Section 5)
SND confirmed and reversible causes addressed
Patient inputs (14)
Pacemaker indication; reversibility (ACC/AHA/HRS 2018 Section 4)
Brady severity; chronotropic response (ACC/AHA/HRS 2018 Kusumoto)
BB / non-DHP CCB / digoxin / ivabradine / donepezil / lithium / amiodarone (ACC/AHA/HRS 2018 reversible-cause checklist)
Ischemic SND (ACC/AHA/HRS 2018 Section 4.1.1)
Adjust AVN-blockers (ACC/AHA/HRS 2018 drug-induced SND)
Hypothyroid reversible cause (ACC/AHA/HRS 2018 Section 4.1.1 reversible causes)
Electrolyte reversible cause; AAD safety (ACC/AHA/HRS 2018)
DOAC + AAD dosing (ACC/AHA/HRS 2023 AF guideline renal-adjusted dosing)
Brady, pauses, AV conduction, P-wave morphology (ACC/AHA/HRS 2018 Class I)
Symptom-rhythm correlation; pause documentation (ACC/AHA/HRS 2018 Class I ambulatory monitoring)
Structural disease; EF (ACC/AHA/HRS 2018 Section 4)
Hemodynamic stability (ACLS 2020 bradycardia algorithm)
AC indication if AF burden (ACC/AHA/HRS 2023 AF guideline CHA2DS2-VASc)
Ischemic SND — inferior MI (ACC/AHA/HRS 2018 Section 4.1.1)
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Severity triggers (7)
- informationallife_threateninghemodynamic_instability_bradySBP <90 with HR <50 and signs of shockTrigger could not be auto-evaluated — needs clinician judgement.
- informationalseveresyncope_with_documented_pause_gt_3sSyncope with documented sinus pause >3 s on monitorTrigger could not be auto-evaluated — needs clinician judgement.
- informationalseveretachy_brady_after_AF_conversionPause >3 s after spontaneous AF conversionTrigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereAAD_induced_brady_in_SND_without_PPMNew brady or pauses on amiodarone / sotalol / flecainide before PPMTrigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderatereversible_drug_induced_bradyBrady on BB / non-DHP CCB / digoxin / donepezil / ivabradine / lithiumTrigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderatechronotropic_incompetence_on_stressFailure to reach 80% age-predicted HR on exercise stressTrigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderatehigh_AF_burden_post_PPMDevice-detected AF burden ≥6 min in 24 hTrigger could not be auto-evaluated — needs clinician judgement.
Workflow calculators
Run this disease's risk and dosing calculators inline.
Recommended regimen
Acute brady management before / pending pacemaker- atropinefirst lineantimuscarinic0.5 mg IV q3–5 min, max 3 mg • IV • q3–5 mintriggers: symptomatic_brady, pre_pacingACLS 2020 bradycardia algorithm first-line; less effective in infranodal block (ACC/AHA/HRS 2018 Kusumoto)rxcui 1223
- isoproterenolsecond linebeta_agonist2–10 mcg/min • IV • continuoustriggers: atropine_unresponsive, pacing_unavailableβ1/β2 agonist increases SA rate; bridge to pacing (ACLS 2020; ACC/AHA/HRS 2018)rxcui 6054
- epinephrinesecond linesympathomimetic2–10 mcg/min • IV • continuoustriggers: atropine_unresponsive, shock_with_bradyBridge to pacing (ACLS 2020 bradycardia algorithm)rxcui 3992
- dopaminesecond linesympathomimetic5–20 mcg/kg/min • IV • continuoustriggers: atropine_unresponsive_with_hypotensionChronotrope + inotrope (ACLS 2020 bradycardia algorithm)rxcui 3628
outpatient playbook — drug actions (2)
- 1. continue rate / rhythm regimenper chosen agent • PO • daily / BIDtrigger: MaintenanceSymptom and recurrence control (ACC/AHA/HRS 2023 AF)
- 2. continue DOAC if AF burdenapixaban / rivaroxaban / dabigatran / edoxaban • PO • daily / BIDtrigger: CHA2DS2-VASc indicationStroke prevention (ACC/AHA/HRS 2023 AF Class I)
Auto-drafted A&P note
outpatientSubjective
- Possible entry pathways: Unexplained syncope or near-syncope (ACC/AHA/HRS 2018 Class I evaluation); Chronic fatigue / exercise intolerance (ACC/AHA/HRS 2018 SND symptom criteria); Palpitations alternating with brady episodes (ACC/AHA/HRS 2018 tachy-brady definition).
Objective
- No vitals, labs, or imaging entered for this encounter.
Assessment
**Brady-tachy syndrome / sick sinus syndrome** (cardio.brady_tachy_syndrome.v1). Phenotype framing: SND vs AV block vs vagally mediated vs drug-induced vs ischemic vs infiltrative (ACC/AHA/HRS 2018 Section 4 differential) Scope: Confirm SND with documented brady + symptom correlation; rule out reversible causes — drug, hypothyroid, OSA, electrolyte, ischemia, infiltrative (ACC/AHA/HRS 2018 Section 4.1 Kusumoto; ESC 2021 pacing Section 5) No severity triggers fired against current inputs.
Plan
Regimen axis: **Acute brady management before / pending pacemaker**. 1. atropine 0.5 mg IV q3–5 min, max 3 mg IV q3–5 min (antimuscarinic, first line) — ACLS 2020 bradycardia algorithm first-line; less effective in infranodal block (ACC/AHA/HRS 2018 Kusumoto) 2. isoproterenol 2–10 mcg/min IV continuous (beta_agonist, second line) — β1/β2 agonist increases SA rate; bridge to pacing (ACLS 2020; ACC/AHA/HRS 2018) 3. epinephrine 2–10 mcg/min IV continuous (sympathomimetic, second line) — Bridge to pacing (ACLS 2020 bradycardia algorithm) 4. dopamine 5–20 mcg/kg/min IV continuous (sympathomimetic, second line) — Chronotrope + inotrope (ACLS 2020 bradycardia algorithm) Setting playbook (outpatient) — Long-term PPM management, AAD if needed, AC, lifestyle 5. continue rate / rhythm regimen per chosen agent PO daily / BID — Maintenance (Symptom and recurrence control (ACC/AHA/HRS 2023 AF)) 6. continue DOAC if AF burden apixaban / rivaroxaban / dabigatran / edoxaban PO daily / BID — CHA2DS2-VASc indication (Stroke prevention (ACC/AHA/HRS 2023 AF Class I)) Non-pharmacologic actions: - EP q3–6 mo (ACC/AHA/HRS 2018 Section 4.1) - PPM check q3–12 mo (ESC 2021 pacing Section 7) - OSA evaluation (ACC/AHA/HRS 2018 reversible-cause checklist) - Vaccinations (AHA/ACC preventive care) AVOID / contraindication checks: - Atropine caution in AV block with wide escape - Isoproterenol caution in CAD
Monitoring
Regimen monitoring: - continuous ECG — ACLS 2020 - BP q5 min — ACLS 2020 bradycardia algorithm - transcutaneous then transvenous pacing setup — ACC/AHA/HRS 2018 Class I Setting (outpatient) monitoring: - Remote PPM monitoring (ESC 2021 pacing Section 7) - AF burden alerts (ACC/AHA/HRS 2023 AF; ASSERT Healey 2012) Follow-up plan: EP q3–6 mo; PPM check; AC review; lifestyle — OSA management, exercise (ACC/AHA/HRS 2018; ESC 2021 pacing follow-up) - Close-out criterion: Follow-up booked Monitoring phase: Pacemaker interrogation; AF burden; symptom diary (ESC 2021 pacing Section 7 remote monitoring; ACC/AHA/HRS 2018)
Disposition
Current setting: outpatient — Long-term PPM management, AAD if needed, AC, lifestyle Disposition criteria: - Continue chronic management (ACC/AHA/HRS 2018; ESC 2021 pacing) Escalation triggers (move to higher acuity): - New syncope despite PPM → device interrogation (ACC/AHA/HRS 2018) - High AF burden → AAD or ablation referral (ACC/AHA/HRS 2023 AF)
Earlier-Return Triggers
Return-precaution thresholds (watch for): - [LIFE_THREATENING] SBP <90 with HR <50 and signs of shock - [SEVERE] Syncope with documented sinus pause >3 s on monitor - [SEVERE] Pause >3 s after spontaneous AF conversion
Citations
- 2018 ACC/AHA/HRS Bradycardia Guideline (Kusumoto) [PMID:30412709](https://pubmed.ncbi.nlm.nih.gov/30412709/) - Cited evidence (PMID 12087119) [PMID:12087119](https://pubmed.ncbi.nlm.nih.gov/12087119/) - Cited evidence (PMID 21870978) [PMID:21870978](https://pubmed.ncbi.nlm.nih.gov/21870978/) - Cited evidence (PMID 12466506) [PMID:12466506](https://pubmed.ncbi.nlm.nih.gov/12466506/) Last reconciled with current guidelines: 2026-04-27.
- 2018 ACC/AHA/HRS Bradycardia Guideline (Kusumoto) — PMID:30412709
- Cited evidence (PMID 12087119) — PMID:12087119
- Cited evidence (PMID 21870978) — PMID:21870978
- Cited evidence (PMID 12466506) — PMID:12466506