ACLS: Tachycardia

1) Evaluate Patient

[definition]

Info: HR typically 150/min or greater; assess appropriateness of rate for clinical condition; patients with impaired ventricular function and instability more likely to be symptomatic at HR <150/min

[assess respiratory and cardiac status]

Info: confirm pulse present; maintain patent airway, assist breathing as needed; give oxygen if hypoxemic; pulse oximetry; monitor BP; cardiac monitor to assess rhythm; establish IV/IO access; 12-lead ECG if available; do not delay cardioversion if patient unstable

2) If Patient Unstable

[symptoms]

Info: persistent tachyarrhythmia causing hypotension, altered mental status, shock, ischemic chest discomfort, acute heart failure

[synchronized cardioversion]

Info: ensure synchronization marker present over R wave; confirm oxygen saturation monitor, suction, IV line, intubation equipment available at bedside; consider sedation if trained personnel available and patient condition permits

Atrial fibrillation: 200 J

Atrial flutter: 200 J

Narrow-complex tachycardia: 100 J

Monomorphic VT: 100 J

Polymorphic VT: unsynchronized, high-energy shock (defibrillation)

[consider adenosine ONLY if regular narrow complex]

Dose: 6 mg IV x1, then 12 mg IV x1 prn after 1-2min; Info: give all doses rapid IV push over 1-3sec, follow each dose with 20 mL NS flush; decr. initial dose to 1 mg IV x1 only if cardiac transplant or central line; contraindicated in patients with asthma

3) If Patient with Refractory Tachyarrhythmia

[treat reversible causes]

5H's: hypovolemia, hypoxia, hydrogen ion (acidosis), hypo/hyperkalemia, hypothermia

5T's: tension pneumothorax, tamponade (cardiac), toxins, thrombosis (pulmonary), thrombosis (coronary)

[management]

Info: consider stepwise incr. in energy level for cardioversion; consider antiarrhythmic tx; consider expert consultation

4) If Patient Stable with wide QRS

[consider expert consultation]

Info: QRS 0.12sec or greater; wide complex tachycardias include VT, SVT with aberrancy, WPW syndrome, ventricular paced rhythms

[consider adenosine ONLY if rhythm regular and monomorphic]

Dose: 6 mg IV x1, then 12 mg IV x1 prn after 1-2min; Info: give all doses rapid IV push over 1-3sec, follow each dose with 20 mL NS flush; decr. initial dose to 1 mg IV x1 only if cardiac transplant or central line; contraindicated in patients with asthma

[consider antiarrhythmic therapy]

Info: consider cardioversion if unsuccessful; use single antiarrhythmic agent; obtain expert consultation before giving 2nd antiarrhythmic agent

procainamide 10-17 mg/kg/dose IV x1 given at 20-50 mg/min until arrhythmia suppressed, hypotension, QRS incr. 50% or max dose 17 mg/kg given, then maintenance infusion 1-4 mg/min IV; Info: avoid if prolonged QT, if receiving other drugs that may prolong QT, or if CHF

amiodarone 150 mg IV x1 over 10min, repeat prn if VT recurs, then maintenance infusion 1 mg/min IV x6h, then 0.5 mg/min IV x18h; Max: 2.2 g/24h

5) If Patient Stable with narrow QRS

[consider expert consultation]

Info: QRS <0.12sec; narrow complex tachycardias include sinus tachycardia, afib, aflutter, AV nodal reentry, accessory pathway-mediated tachycardia, atrial tachycardia, MAT, junctional tachycardia

[vagal maneuvers]

Info: carotid massage or valsalva maneuver terminates 25% of SVT; 75% will need adenosine

[adenosine ONLY if regular and monomorphic]

Dose: 6 mg IV x1, then 12 mg IV x1 prn after 1-2min; Info: give all doses rapid IV push over 1-3sec, follow each dose with 20 mL NS flush; decr. initial dose to 1 mg IV x1 only if cardiac transplant or central line; contraindicated in patients with asthma

[calcium channel blocker or beta blocker]

diltiazem 0.25 mg/kg IV x1 over 2min, then may give 0.35 mg/kg IV x1 after 15 min, then maintenance infusion 5-15 mg/h IV titrated to HR; Info: avoid if impaired ventricular function or heart failure; do not use if wide QRS complex or pre-excited afib or aflutter

verapamil 2.5-5 mg IV x1 over 2-3 min, then 5-10 mg IV q15-30min to max 20 mg/total dose; Alt: 5 mg IV over 2-3min q15min to max 30 mg/total dose; Info: avoid if impaired ventricular function or heart failure; do not use if wide complex tachycardia or pre-excited afib or aflutter

metoprolol 2.5-5 mg IV x1 over 2min, may repeat q5min up to 3 doses; Info: caution if COPD or CHF

esmolol 500 mcg/kg IV x1 over 1min, then maintenance 50 mcg/kg/min IV, may incr. 50 mcg/kg/min IV q4min up to max 300 mcg/kg/min; for more rapid rate control, may repeat 500 mcg/kg IV load prior to each maintenance infusion rate incr. up to 3 total loading doses; Info: caution if COPD or CHF