Lignocaine Use in Ventricular Tachycardia

Introduction to Lignocaine Administration

The American College of Cardiology recommends lignocaine as a second-line agent for stable VT, with amiodarone and beta-blockers preferred as first-line therapy, particularly in patients with structural heart disease 2
For hemodynamically stable ventricular tachycardia, lignocaine is administered as an initial bolus of 50 mg IV over 2 minutes, repeated every 5 minutes to a total dose of 200 mg, followed by a maintenance infusion of 2 mg/min 1

Before administering lignocaine, assess whether the patient is hemodynamically stable or unstable by checking for systolic blood pressure ≤90 mmHg, chest pain suggesting ongoing ischemia, acute heart failure with pulmonary edema, altered mental status indicating inadequate cerebral perfusion, and signs of shock 2
If any of these adverse signs are present, immediate synchronized DC cardioversion (100J, 200J, 360J) takes priority over drug therapy 3, 1, 2

The European Society of Cardiology recommends amiodarone (150 mg IV over 10 minutes, then 1.0 mg/min infusion) combined with IV beta-blockers as the preferred initial treatment for hemodynamically stable VT 2
For stable VT with pulse, the initial dose of lignocaine is 50 mg IV over 2 minutes, repeated every 5 minutes to a total dose of 200 mg, followed by a maintenance infusion of 2 mg/min 1
Alternative dosing (ACC/AHA Protocol) includes a loading bolus of 1.0-1.5 mg/kg IV (maximum 100 mg), with additional boluses of 0.5-0.75 mg/kg every 8-10 minutes if needed, and a maximum total loading of 3-4 mg/kg 4, 5, 1

Lignocaine remains the drug of choice specifically in the acute MI setting when VT occurs 4, 5
Reduce the maintenance infusion rate in elderly patients (≥70 years), heart failure or cardiogenic shock, and after 24-48 hours 5, 4, 1
Monitor continuously for early signs of central nervous system toxicity, including nausea, drowsiness, perioral numbness, dizziness, confusion, slurred speech, muscle twitching, seizures, and respiratory depression 1

Do not use lignocaine as first-line therapy in polymorphic VT storm, torsades de pointes, severe shock, or heart block 6, 2, 3, 4
Lignocaine depresses myocardial contractility, requiring careful monitoring especially in hemodynamically compromised patients 1

If VT persists or recurs despite lignocaine, amiodarone is indicated for VT refractory to lignocaine: 5 mg/kg (300 mg) over 15 minutes for life-threatening situations, or over one hour for stable patients 1
Procainamide is an alternative: 20-30 mg/min up to 10-17 mg/kg loading dose 1, 2
Bretylium is used for refractory VT: 5 mg/kg diluted with 100 mL dextrose, with possible further dose of 10 mg/kg 4, 1