ACLS Megacode 1: Ventricular Rhythms

Patient is having active chest pain and appears uncomfortable. An EKG should be done as soon as possible, within minutes of his arrival. STEMI is very high in differential, but chest pain is not always indicative of Acute Coronary Syndrome (ACS) and a focused history and physical, with simultaneous addressing of ABC’s/CAB is imperative.

The patient’s EKG demonstrates anterior STEMI with ST elevation in V1 - V4 with reciprocal changes in the inferior leads (II, III, AVF). Aspirin is the therapy that has been proven to improve morbidity and mortality in STEMI patient and should be given as soon as possible. Early intervention via cardiac catheterization is imperative. If emergent catheterization is not available at your facility; lytic therapy should be provided.

The rhythm demonstrates ventricular fibrillation. This is a non-perfusing, life-threatening rhythm. The best intervention is early defibrillation. Start CPR and manual bagging to treat circulation and breathing, while the defibrillator is charging. As soon as available, defibrillate the patient.

The answer is Biphasic defibrillators deliver electricity in two vectors which allows for effects at lower electricity. It is important to be familiar with your facilities instruments. Make a point to look at the defibrillator available at your hospital to determine its type as well as to familiarize yourself with its use.

After defibrillation, continue with effective CPR to aid in circulation. Atropine is not indicated and cessation of efforts after only one round of defibrillation and CPR is inappropriate. Provided early defibrillation and effective CPR with witnessed cardiac arrest can markedly increase chance of survival. While one can consider intubation, new ACLS guidelines stress CAB, circulation, airway, breathing. You do not want to ignore the airway, but manually bagging with appropriate patient positioning can provide sufficient oxygenation and ventilation. If a patient regains a pulse and an airway is required, intubation can then be performed.

This demonstrates ventricular tachycardia without a pulse. As with ventricular fibrillation, the best initial treatment is early defibrillation, followed by CPR, administration of epinephrine and possibly amiodarone as per algorithm.

You must constantly assess and re-asses the patient. After rounds of CPR, check a pulse and rhythm as part of your re-assessment as this can change management.

This patient has unstable ventricular tachycardia with a pulse. Synchronized cardio version should be initiated. Defibrillating a patient with a pulse can be life threatening. If there is any question whether the patient has a pulse or not, synchronized cardiovert.

You have successfully restored patient’s circulation. However, now that the patient has pulse and blood pressure, continue to treat CAB. Clinically, the patient seems to require a more definitive airway as evidenced by shallow respirations and hypoxia and unresponsiveness. Remember, the patient’s initial pathology was ST elevation MI, likely precipitating V Fib arrest. Once the patient has a pulse, early intervention with cardiac catheterization can be life-saving.

Epinephrine is indicated for V Fib/pulseless v tach. Amiodarone is also an appropriate medication to provide. However, when patient is pulseless/coding, the dose is 300 mg, followed by a second dose of 150 mg if needed. 150 mg is indicated for stable ventricular tachycardia with a pulse.