263.4 📌 章末速蚘

263.4.0.0.1 Sinus Node Dysfunction
  • Sinus bradycardia + pauses + chronotropic incompetence + tachy-brady
  • Elderly degenerative
  • Symptomatic = pacemaker
263.4.0.0.2 AV Blocks
  • 1°: PR > 200 ms (benign)
  • Mobitz I (Wenckebach): progressive PR → drop; atropine works; benign
  • Mobitz II: constant PR + dropped beats; pacemaker often (high progression)
  • 3° (Complete): AV dissociation; pacemaker essentially always
263.4.0.0.3 Pacemaker Modes
  • VVI: chronic AF
  • AAI: SSS without AV block
  • DDD: sinus + AV block (most common)
  • CRT (Biventricular): HFrEF + LBBB + symptomatic
263.4.0.0.4 Indications Class I
  • Symptomatic SSS
  • Mobitz II
  • 3° AV block
  • Post-MI persistent AV block
  • Symptomatic carotid sinus hypersensitivity
263.4.0.0.5 2024 Innovations
  • Leadless pacemakers (Micra, Aveir)
  • Conduction system pacing (HBP, LBBAP) — more physiologic
  • MRI-conditional pacemakers
263.4.0.0.6 Bifascicular Block + Syncope
  • EP study (HV interval > 100 ms = pacemaker)
  • ILR for monitoring
263.4.0.0.7 MI + AV Block
  • Inferior MI: often Mobitz I (transient, RCA vagal); resolves
  • Anterior MI: Mobitz II / complete (His-Purkinje); pacemaker often
263.4.0.0.8 Drug-Induced Bradycardia
  • BB, CCB (verapamil/diltiazem), digoxin, amiodarone, ivabradine
  • Withdraw before pacemaker decision
263.4.0.0.9 Athlete vs Pathologic
  • Athlete: bradycardia normal at rest, normalizes with exercise
  • SSS: chronotropic incompetence, symptomatic
263.4.0.0.10 盧醫垫 hint
  • Symptomatic bradycardia + reversible cause workup first (drugs, hypothyroidism, electrolyte)
  • Mobitz II + 3° AV block → pacemaker referral
  • Bifascicular block + syncope → EP study
  • HFrEF + LBBB + QRS > 130 + NYHA II-III → CRT consideration
  • Modern pacemakers MRI-conditional → MRI possible with coordination