›Patiromer or sodium zirconium cyclosilicate for definitive outpatient lowering
›Lyme disease treatment
›Mild to moderate disease
›Doxycycline 100 mg PO BID for 14-21 days
›Amoxicillin 500 mg PO TID if doxycycline contraindicated
›Cefuroxime 500 mg PO BID as alternative
›High-degree AV block or severe carditis
›Ceftriaxone 2 g IV daily for 14-21 days
›AV block typically resolves within 1-2 weeks of antibiotics
›Temporary pacing if hemodynamically compromised
›Hypothyroidism treatment
›Levothyroxine replacement
›Starting dose 1.6 mcg/kg/day in young healthy patients
›Starting dose 25-50 mcg/day in elderly or cardiac disease patients
›TSH recheck every 6-8 weeks during titration
›Conduction often partially improves but pacing may still be required
Symptomatic first-degree AV block treatment
›Permanent pacemaker implantation
›Indication: PR >= 300 ms with pseudo-pacemaker syndrome
›Class IIa recommendation per ACC/AHA/HRS 2018 guidelines
›Symptoms: fatigue, dyspnea, hemodynamic compromise from loss of AV synchrony
›Mechanism: atrial systole occurring against closed mitral and tricuspid valves
›Device selection
›Dual-chamber pacemaker to preserve AV synchrony
›AV delay programming to optimize ventricular filling
›Acute symptomatic bradycardia management
›Atropine
›Atropine 0.5 mg IV bolus
›Repeat every 3-5 minutes to maximum 3 mg total
›Effective for AV nodal block
›May be ineffective or paradoxically worsen infranodal block
›Isoproterenol
›Isoproterenol 2-10 mcg/min IV infusion
›Titrate to heart rate and hemodynamic response
›Bridge while awaiting pacemaker
›Contraindicated in ischemic heart disease
›Dopamine
›Dopamine 2-10 mcg/kg/min IV infusion
›Chronotropic at higher doses
›Use when isoproterenol contraindicated
›Transcutaneous pacing
›Immediate option for hemodynamic instability
›Painful; conscious sedation required
›Temporary transvenous pacing
›Definitive bridge to permanent pacing or recovery
Neuromuscular disease and high-risk genetic conditions
›Neuromuscular disease pacing
›Pacemaker consideration for any degree of AV block
›Class IIb recommendation per ACC/AHA/HRS 2018 guidelines
›Unpredictable progression to high-grade block independent of PR interval
›Applies to myotonic dystrophy, Kearns-Sayre, Emery-Dreifuss
›Lamin A/C cardiomyopathy
›Combined pacemaker and defibrillator (ICD)
›High risk of ventricular arrhythmias and sudden cardiac death
›Device with pacing and defibrillation capability typically recommended
›Electrophysiology study to assess ventricular arrhythmia inducibility
›Cardiac sarcoidosis
›Corticosteroid therapy
›Prednisone 0.5 mg/kg/day initial dose
›Titration guided by imaging response and inflammatory markers
›May partially reverse conduction abnormalities
›Pacemaker if high-degree block present
›ICD consideration given risk of ventricular arrhythmias in cardiac sarcoidosis