Sinus bradycardia

(SB, <50–60 bpm) (NEJM 2000;342:703, Circ 2019;140:e382)

• Etiologies:
  • meds
    • βB,
    • CCB,
    • amio,
    • Li, dig
  • ↑ vagal tone (incl. athletes, sleep, IMI),
  • metabolic
    • (hypoxia, sepsis, myxedema, hypothermia, ↓ glc),
    • OSA, ↑ ICP
• Treatment:
  • if no sx, none;
  • atropine,
  • β1 agonists (short-term) or
  • pacing if symptomatic
• Most common cause of sinus pause is: blocked premature atrial beat