How to Read an EKG
Summary: <br> Always remember…1, 2, 3, get an old EKG!!!<br> <br> <br> <br> Step 1: Identify the Rate and Rhythm<br> <br> <br> <br> * Is it sinus rhythm?* P wave before every QRS* Is it one of the tachycardias? (Refer to <a href="http://www.emclerkship.com/tachycardia/">THIS</a> episode)* Is it one of the bradycardias? (Refer to <a href="http://www.emclerkship.com/bradycardia/">THIS</a> episode)<br> <br> <br> <br> Step 2: Look for Signs of Ischemia<br> <br> <br> <br> * Most consistent way is to examine by anatomic region of the heart* II, III, and aVF are “inferior” leads* I, aVL, V5, V6 are “lateral” leads* V1 and V2 are “septal” leads* V3 and V4 are “anterior” leads* Check for Q waves* Check for ST segment elevation or depression* Compare the J point with baseline (TP segment)* Check for peaked T waves and T wave inversions* T wave inversions in V1 and aVR are normal<br> <br> <br> <br> Step 3: Look at Intervals<br> <br> <br> <br> * PR interval* Wolf-Parkinson White Syndrome* 1st degree heart block* QRS interval* Left bundle branch block* Right bundle branch block* Sodium channel blockade* QT interval* Long QT syndrome* Hypokalemia* Risk of torsades de pointes<br> <br> <br> <br> Step 4: Get an Old EKG<br> <br> <br> <br> * If you find anything abnormal looking, compare to an old EKG<br> <br> <br> <br> Bonus: Scarbossa Criteria<br> <br> <br> <br> * Identifies ischemia in patients with a left bundle branch block* 1 lead with concordant ST elevation* 1 lead with concordant ST depression (V1-V3)* Severely discordant ST elevation (>25% preceding S wave)<br> <br> <br> <br> Additional Reading<br> <br> <br> <br> * Basic Approach to Tachycardias <a href="http://www.emclerkship.com/tachycardia/">(EM Clerkship)</a>* Basic Approach to Bradycardias <a href="http://www.emclerkship.com/bradycardia/">(EM Clerkship)</a>* EKGs for the Emergency Physician <a href="https://www.amazon.com/ECGs-Emergency-Physician-Amal-Mattu/dp/0727916548">(Amazon)</a><br>
