Ventricular Tachycardia (VT)
Defined as ≥3 beats at a rate 100 beats per min or greater which may be terminated spontaneously within 30 seconds without causing severe symptoms (non-sustained VT). In hemodynamically unstable patient presented with VT, in addition to other first-line measures, anti-arrythmic drugs is often used:
Amiodarone (first-line therapy)
Procainamide (alternative to amiodarone)
Lidocaine (if suspected acute myocardial ischaemia)
Other drugs that commonly used for management of VT in the ICU is beta-blockers (class II). Metoprolol is usually preferable in ICU setting, can be given orally or IV [e.g esmolol (short-acting)]. For those remain symptomatic despite beta-blockers therapy, or who are unable to tolerate beta-blocker, a non-dihydropyridine calcium channel blocker maybe used.
Drugs commonly used for management of VT in ICU
Amiodarone
150 – 300 mg IV bolus over 10 minutes, followed by infusion of 1mg/min for 6H, then 0.5
mg/min for 18 additional hours or until convert to oral therapy. Additional 150 mg bolus can be given if there is breakthrough arrhythmia (up to total loading 2g per 24H) (some suggest may up to 6-10 g oral loading) Alternative dosing regimens:
Load orally 800 to 1600 mg daily for 2-3 weeks, then maintenance dose of 400mg daily
Oral 200 mg twice daily for 4 weeks, then 200 mg daily (maintenance dose)
Oral 400 mg every 8-12H for 1-2 weeks, followed by 200-400 mg once daily
(maintenance)
Procainamide: Loading up to 17mg/kg (as IV infusion 20-30 mg/min), followed by maintenance 1-4 mg/min
Lidocaine: 1-1.5 mg/kg IV bolus, may repeat up to bolus 3 mg/kg, followed by infusion of 1-4 mg/min
Metoprolol: Usual effective dose 50-200mg daily
Carvedilol: Usual effective dose 12.5 to 50mg daily
Esmolol: 500 mcg/kg IV bolus over 1 minute followed by maintenance dose of 50 mcg/kg/min titrated
for effect up to 300 mcg/kg/min
Verapamil: Usual effective dose 360-480 mg daily
Diltiazem: Usual effective dose 240-360 mg daily
Supraventricular Tachycardia (SVT)
SVT is an abnormal heart rhythm with a ventricular rate of 100 or more beats per minute (faster than normal). It happens because of a problem with the heart’s electrical system. It starts in the upper chambers of the heart, called the “atria” It usually starts and stops suddenly, without warning. SVT is also called “paroxysmal supraventricular tachycardia” or PSVT (paroxysmal means a sudden attack).
The 3 main types of SVT are called:
Atrioventricular nodal reentry tachycardia (AVNRT)
Atrioventricular reentry tachycardia (AVRT)
Atrial tachycardia
Pharmacotherapy for SVT
In stable patient, drugs that are used for treatment of SVT:
Adenosine: 6-12 mg rapid IV push followed by saline flush
IV verapamil, diltiazem or beta-blockers
Type I or type III anti-arrhythmic
Unstable patient:
Electrical cardioversion