ECG Cases – Making complexes simple is a monthly blog by Jesse McLaren (@ECGcases), a Toronto emergency physician with an interest in emergency cardiology quality improvement and education. Each post features a number of ECGs related to a particular theme or diagnosis (with a focus on acute coronary occlusion), so you can test your interpretation skills. We challenge you with missed or delayed diagnosis, those with false positive diagnosis, and those that had a rapid and correct diagnosis. Cases are followed by a quick summary of the literature that relates to the cases, and we bring it home with practice changing pearls that you can use on your next shift.
Share your interesting ECGs with us!
ECG Cases 64 – AV Block Pitfalls and Pearls
AV block can be challenging to recognize and classify on the ECG, particularly when P waves are subtle or conduction patterns are misleading. In this ECG Cases blog, Dr. Jesse McLaren takes a practical, stepwise approach to diagnosing AV block: identifying what the atria are doing, distinguishing nodal from infranodal block, and recognizing reversible causes. Learn how to differentiate Mobitz I, Mobitz II and complete heart block, identify secondary causes using the BRADI mnemonic, and determine which patients may require urgent pacing... Please consider a donation to EM Cases to ensure ongoing FOAMed here: https://emergencymedicinecases.com/donation/
ECG Cases 63 – WPW, Tachyarrhythmias and Ischemic Mimics
Five patients present with possible Wolff-Parkinson-White—but the ECGs tell five very different stories. From palpitations mislabeled as anxiety to narrow- and wide-complex tachyarrhythmias, pseudo-infarction patterns, and a true occlusion MI hidden by pre-excitation, these cases highlight the many faces of WPW. Learn how to recognize intermittent pre-excitation, distinguish AVRT from AF with WPW, choose the right treatment—and avoid potentially dangerous AV nodal blockers...
ECG Cases 62 – ACLS Arrhythmia Pitfalls, Part 5: Stable Narrow Complex Tachycardias
Stable narrow complex tachycardias are not always what they seem. In this ECG Cases, Dr. Jesse McLaren explores the key pitfalls in distinguishing sinus tachycardia, atrial fibrillation, atrial flutter, and SVT, with 8 real-world cases highlighting common ECG interpretation errors, secondary causes, and the crucial management decisions that can prevent patient harm... Please consider a donation to EM Cases to ensure continued Free Open Access Medical Education here: https://emergencymedicinecases.com/donation/
ECG Cases 61 ACLS Dysrhythmia Pitfalls Part 4: Stable Wide Complex Tachycardia
In this month's ECG Cases Dr. Jess McLaren explains how to differentiate various causes and mimics of Wide Complex Tachyardia: Artifact can mimic wide complex tachycardia, but have unaffected leads recorded at the same time, and regular narrow QRS complexes marching through the noise. Too wide or not fast enough? Consider hyperkalemia (empiric calcium) or sodium channel toxicity (empiric sodium bicarbonate). Regular wide complex tachycardia driven by P waves? Treat the secondary cause of sinus tachycardia. VT vs SVT? If the wide complex tachycardia is regular and not driven by P waves, and the differential is VT vs SVT, assume VT regardless of age or hemodynamic instability (eg fascicular VT in young patients) and much more...Please consider a donation to help ensure we continue to provide high quality Free Open Access Medical Education here: https://emergencymedicinecases.com/donation/
ECG Cases 60 – ACLS arrhythmia pitfalls, part 3: unstable tachycardia, cardiovert?
This is the third in a series of blog posts on the pitfalls of ACLS algorithms for adults with a pulse, and how a systematic approach to 12-lead ECG can help with ECG acquisition, interpretation, and application. The first looked at unstable bradycardia, the second stable bradycardia, and this one will look at unstable tachycardia. The ACLS algorithm for unstable tachyarrhythmia is simple: immediate cardioversion. This works well if it is a primary tachyarrythmia that is causing the instability (eg SVT or VT), but there are a number of pitfalls in this assumption. ECG acquisition: is it actually a tachy-arrhythmias? Artifact can mimic a tachy-arrhythmia. This can be identified by unaffected leads recorded at the same time, and narrow QRS complexes marching through the noise ECG interpretation: is the tachy-arrhythmia a primary electrical problem? There are other tachycardias in unstable patients that may fail to respond to cardioversion: AF (irregularly irregular rhythm), where the patient’s instability may be related to a secondary cause Sinus tachycardia (in response to a secondary cause): can best be identified by upright P waves in II and biphasic P waves in V1. ECG application: Is the rhythm causing the instability, or is there a secondary cause – including one that might be revealed by the 12-lead, like hyperkalemia or occlusion MI? For live and highly interactive ECG courses to elevate your skills - including online courses, or an in-person pre-conference course at CAEP, go to www.heartsECGcourse.com
ECG Cases 59 – ACLS Dysrhythmia Pitfalls Part 2: Stable Bradycardia? Or Dangerous Bradycardia Requiring Pacemaker?
Five patients presented with bradycardia and normal blood pressure. How does ECG interpretation change management? Despite apparent stability, which require immediate treatment and which require admission for a pacemaker?...
