Lidocaine's Effects on Heart Rate and Arrhythmias

Primary Cardiac Effects

• The American College of Cardiology notes that lidocaine is primarily a sodium channel blocker that does not work through rate control mechanisms, unlike beta-blockers, calcium channel blockers, or digoxin 2, 4
• Lidocaine does not significantly affect AV nodal conduction or sinus node automaticity at therapeutic doses, according to the American College of Cardiology 2, 3

Contraindication in Specific Arrhythmias

• The American College of Cardiology/American Heart Association explicitly contraindicates lidocaine in Wolff-Parkinson-White syndrome with atrial fibrillation, as it can facilitate antegrade conduction along the accessory pathway, resulting in acceleration of ventricular rate, hypotension, or ventricular fibrillation 4

Negative Chronotropic Effects as Toxicity

• The American College of Cardiology states that bradycardia and asystole represent toxic effects of lidocaine, not therapeutic actions, and can occur in patients with acute myocardial infarction 1, 5
• The incidence of asystole with lidocaine use in acute MI may obscure the favorable influence of ventricular arrhythmia suppression, according to the American College of Cardiology 1, 5

Clinical Implications

• The American College of Cardiology recommends lidocaine for ventricular tachycardia and ventricular fibrillation in the acute MI setting, as well as for frequent, closely coupled, multiform, or runs of ≥3 ventricular premature beats 1, 2, 5
• The American College of Cardiology advises against using lidocaine in atrial fibrillation or atrial flutter where rate control is the goal, and in patients requiring negative chronotropic effects, recommending beta-blockers, calcium channel blockers, or digoxin instead 4