NBME Shelf Review (Part 6) – Common Arrhythmias

“Unstable” Arrhythmias

* Arrhythmias that cause* Hypotension* Pulmonary Edema* Chest Pain* Altered Mental Status

Supraventricular Tachycardia (SVT)

* Stable* Vagal maneuver* Adenosine* Beta blocker or calcium channel blocker* Unstable* SYNCHRONIZED cardioversion

Monomorphic Ventricular Tachycardia (VT)

* Stable* Amiodarone* Procainamide* Lidocaine* Unstable* SYNCHRONIZED cardioversion* Pulseless* Defibrillation

Polymorphic Ventricular Tachycardia (aka Torsades de Pointes)

* Known complication of prolonged QTc* Side effect of multiple medications* Antipsychotics* Methadone* Ondansetron* Give Magnesium Sulfate

High yield EKG patterns

* Long QTc* Wolf Parkinson White (WPW)* Brugada Pattern

Atrial Fibrillation

* Stable* Patient presents immediately after onset (<24-48 hours)* Synchronized cardioversion* Rhythm control medications* Amiodarone* Procainamide* Flecanide* Patient does not present immediately (or unknown onset)* Rate control* Beta blockers* Metoprolol* Calcium channel blocker* Diltiazem* Anticoagulation (heparin)* Unstable* Synchronized cardioversion* Atrial fibrillation with extremely fast rate (200+) is common in WPW* Atrial fibrillation with slow rate is common with Digoxin toxicity

Bradycardia

* AV Blocks* 1st Degree* 2nd degree (type 1)* 2nd degree (type 2)* 3rd degree* If symptomatic and stable…* Atropine* If they become unstable… * Transcutaneous or transvenous pacing

Additional Reading

* Life in the Fast Lane EKG Library (LITFL)* Tachycardias (EM Clerkship)* Bradycardias (EM Clerkship)