There are several algorithms that are currently used to help distinguish Supraventricular Tachycardia (SVT) with aberrancy and Ventricular Tachycardia (VT). Many of these algorithms lack specificity, and let’s face it, who can remember if the absence of an RS complex in the precordial leads is VT or SVT with aberrancy. So what if there was a criterion that had a good sensitivity (SN), specificity (SP), and was one simple step?
Due to the overwhelming popularity of Dr. Salim Rezaie‘s recent post discussing the Brugada criteria for SVT with aberrancy vs VT, Dr. Jason West (@JWestEM, an EM resident from Jacobi/Montefiore) kindly helped to co-author and package this information into a PV card for quick reference. To use this sequential, four-question approach, if at any time you answer YES to the question, it is ventricular tachycardia.
Posterior myocardial infarction (MI) represents 3.3 – 21% of all acute MIs and can be difficult to diagnose by the standard precordial leads. Typically, leads V7 – V9 are needed to diagnose this entity. Luckily, leads V1 – V3, directly face the posterior wall of the left ventricle and are the “mirror image” of the posterior wall of the left ventricle.
Last week, the Patwari Academy videos covered ECG basics on rate, rhythm, and axis. Here is another set of three videos discussing ECG intervals and segments — specifically the PR interval, QRS interval, and ST segments. Again, this is a nice review on ECG concepts.
Differentiating between SVT with aberrancy and VT can be very difficult. It is crucial to be able to make this distinction as therapeutic decisions are anchored to this differentiation. Brugada et al prospectively analyzed 384 patients with VT and 170 patients with SVT with aberrant conduction to see if it was possible to come up with a simple criteria to help differentiate between the two with high sensitivity and specificity.
Dr. Rahul Patwari reviews the basics on how to determine an ECG’s rate, rhythm, and axis. It’s always nice to review these concepts. Do you remember how many seconds a traditional ECG typically spans on a single page? What’s the significance of the numbers: 300, 150, 100, 75, 60, 50? Spend a few minutes on these 2 refresher videos.
EKGs are a simple, cheap modality that can give an emergency physician quite a bit of information. Sometimes, in a busy ER, this information can be very subtle and almost overlooked without a second thought. A perfect example of this is a New Tall T-wave in lead V1 (NTTV1). This finding can be a normal variant, but can also be a precursor to badness.