Cardioversion and defibrillation

Emergency re-establishment of an organized electrical rhythm

• Hemodynamically unstable polymorphic ventricular tachycardia

• Ventricular fibrillation

• Pulseless ventricular tachycardia

• Narrow or wide QRS complex tachycardia (ventricular rate >150) associated with hemodynamic instability, chest pain, or pulmonary edema

Elective reestablishment of sinus rhythm

• Atrial fibrillation

• Atrial flutter

• Hemodynamically stable ventricular tachycardia unresponsive to medical treatment

• Others

Specific advance directives (e.g., do not attempt resuscitation for cases of ventricular fibrillation)

Digitalis toxicity–associated tachycardia

Sinus tachycardia caused by various clinical conditions

Rhythms not responsive to electric shock (e.g., multifocal atrial tachycardia)

Atrial fibrillation or atrial flutter without proper anticoagulation or exclusion of atrial thrombi