›Irreversible sinus node dysfunction with symptoms
›Complete AV block with junctional escape and symptoms
›Escape rate < 40 bpm or asystole >= 3 seconds
›2018 ACC/AHA/HRS Guideline Class I recommendation
›Digoxin toxicity management
›Hold all digoxin immediately
›Digoxin-specific antibody fragments (Digibind/DigiFab)
›Indications: life-threatening arrhythmias, ventricular arrhythmias, high-grade AV block
›Dose based on body load or digoxin level
›Empiric dose: 10-20 vials IV if level unknown in severe toxicity
›Potassium repletion
›Target potassium > 4.0 mmol/l
›IV replacement if severe hypokalemia or symptomatic
›Avoid calcium if digoxin toxicity suspected
›May precipitate fatal arrhythmias
›Medication-induced junctional rhythm
›Discontinue or reduce offending agent
›Expected resolution within 24-48 hours of drug discontinuation
›Electrolyte correction
›Potassium: goal > 4.0 mmol/l
›IV KCl 10-20 mmol/hr via central or peripheral line
›Magnesium: goal > 0.8 mmol/l
›Magnesium sulfate 2-4 g IV over 10-20 minutes for severe deficiency
›Acute inferior MI
›Standard ACS management with reperfusion strategy
›Junctional rhythm often resolves spontaneously with revascularization
›Avoid AV nodal blocking agents if junctional rhythm is escape
Junctional tachycardia — rate control
›Acute rate control (symptomatic, rate > 100 bpm)
›IV beta-blockers — first-line
›Metoprolol 5 mg IV over 2 minutes, may repeat x 3 doses
›Propranolol 1-3 mg IV over 1 minute, may repeat after 2 minutes
›Class IIa recommendation, 2015 ACC/AHA/HRS SVT Guideline
›IV calcium channel blockers — if beta-blockers ineffective or contraindicated
›Diltiazem 0.25 mg/kg IV over 2 minutes (max 25 mg), then 5-15 mg/hr infusion
›Verapamil 2.5-5 mg IV over 2 minutes, may repeat 5-10 mg after 15-30 minutes
›Class IIa recommendation
›IV procainamide — if above ineffective
›15-17 mg/kg IV over 30-60 minutes
›Maintenance infusion 1-4 mg/min
›Class IIa recommendation
›Chronic oral management
›Beta-blockers — first-line oral therapy
›Metoprolol succinate 25-200 mg daily
›Atenolol 25-100 mg daily
›Oral diltiazem or verapamil — alternative
›Diltiazem ER 120-360 mg daily
›Verapamil ER 120-360 mg daily
›Flecainide or propafenone — refractory cases
›Flecainide 50-150 mg twice daily
›Propafenone 150-300 mg three times daily
›Avoid in structural heart disease or reduced ejection fraction
›Procedural intervention
›Focal junctional tachycardia refractory to medical therapy
›Class IIb recommendation, 2015 ACC/AHA/HRS Guideline
›Risk of complete AV block requiring pacemaker (approximately 1-2%)
›High success rate for focal junctional tachycardia (> 80%)
›Pre-ablation evaluation
›EPS for definitive diagnosis if uncertain
›Echocardiogram to exclude structural disease