Anti-Arrhythmics

Anti-Dysrhythmic

- Description: Adenosine is a naturally occurring agent that can "chemically cardiovert" PSVT into normal sinus rhythm. It has a half life of 10-seconds and does not cause hypotension.

- Indications: Narrow, complex, paroxysmal supraventricular tachycardia refractory to vagal manuevers.

- Contraindications: 2nd and 3rd degree heart block, sinus node disease, or asthma.

- Precautions: It may cause transient dysrhythmias, especially asystole, COPD

• - Dosage/Route: 6 mg rapidly (over 1 to 2 seconds) IV, then flush line rapidly with saline. If ineffective, 12 mg in 1 to 2 mins, may be repeated.
• -Pedi: 0.1 mg/kg (over 1 to 2 seconds) IV, followed by rapid saline flush, then 0.2 mg/kg in 1 to 2 mins to max 12 mg.

Anti-Dysrhythmic (KCl Blocker)

- Description: Amiodarone is an anti-dysrhythmic that prolongs the duration of the action potential and refractory period and relaxes smooth muscles, reducing peripheral vascular resistance and increasing coronary blood flow.

- Indications: Life-threatening ventricular and supraventricular dysrhythmias, frequently atrial fibrillation.

- Contraindications: Cardiogenic shock, severe sinus bradycardia, or advanced heart block.

- Precautions: Hepatic impairment, pregnancy, nursing mothers, children

• - Dosage/Route: 150 to 300 mg IV over 10 mins, then 1 mg/min over next 6 hours.
• -Pedi: 5 mg/kg IV/IO then 15 mg/kg/day.

Anti-dysrhythmic (KCL Blocker)

- Description: Bretylium causes a release of norepinephrine, depresses ventricular fibrillation, and reduces ectopy. Bretylium suppresses ventricular tachydysrhythmias including vfib with re-entry mechanisms.

- Indications: Ventricular fibrillation and ventricular tachycardia refractory to lidocaine.

- Contraindications: None

- Precautions: Digitalized patients, digitalis induced dysrhythmias.

- Dosage/Route: 5 mg/kg IV then 10 mg/kg/10 to 15 mins to a max of 30 mg/kg

Anti-dysrhythmic/ NA+ blocker

- Description: Lidocaine is an anti-dysrhythmic that suppresses automaticity and raises stimulation threshold of the ventricles. It also causes sedation, anticonvulsant, and analgesic effects.

- Indications: Pulseless ventricular tachycardia, ventricular fibrillation, ventricular tachycardia (w/ pulse)

- Contraindications: Hypersensitivity to amide-type local anesthetics, supraventricular dysrhythmias, Stokes-Adams syndrome, 2nd and 3rd degree heart blocks, and bradycardias.

- Precautions: Hepatic or renal impairment, CHF, hypoxia, respiratory depression, hypovolemia, myasthenia gravis, shock, elderly.

• - Dosage/Route:
• Cardiac Arrest: 1 to 1.5 mg/kg slow IV, repeated every 3 to 5 mins, up to 3 mg/kg. Follow conversion with a drip of 2 to 4 mg/min.
• Pedi: 1 mg/kg slow IV, repeated every 3 to 5 mins, up to 3 mg/kg. Follow conversion with a drip of 20 to 30 mcg/kg/min.
• Ventricular Tachycardia (w/ pulse): 1 to 1.5 mg/kg slow IV. Consider lower dose for elderly. May repeat 1/2 dose every 5 to 10 mins until conversion up to 3 mg/kg. Follow conversion with 2 to 4 mg/min.
• Pedi: 1 mg/kg followed by a drip of 20 to 50 mcg/kg/min.

Anti-arrhythmic (NA+ blocker)

- Description: Procainamide prolongs ventricular repolarization, slows conduction, and decreases myocardial excitability.

- Indications: Ventricular fibrillation, pulseless ventricular tachycardia refractory to lidocaine.

- Contraindications: Hypersensitivity to procainamide or procaine, myasthenia gravis, 2nd and 3rd degree heart block,

- Precautions: Hypotension, cardiac enlargement, CHF, AMI, ventricular disrhythmias from digitalis, hepatic or renal impairment, or bronchial asthma.

• - Dosage/Route: 20 to 30 mg/min IV drip Stop points: (1) up to 17 mg/kg to effect, then 1 to 4 mg/min. (2) ectopy resolves (3) QRS complex widens more than 50% from original. (4) Hypotension ensues.
• Pedi: 15 mg/kg IV/IO over 30 to 60 mins.