EKG of the Week
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This EKG was done on a 46 year old with 1-2 days of worsening of abdominal and chest pain, now lasting for several hours.
+ EKG Interpretation
Dr. Ohlbaum's Explanation
The rhythm is regular and the rate is fast. The computer read it as sinus tachycardia. Is it? Well, what can be regular and fast and narrow? Really only a few options:
- Sinus tach - But this is not a 20 yr old on a treadmill. It is an older patient lying on a bed. While there are certainly exceptions, usually sinus tach is going to be <140 data-preserve-html-node="true"
- SVT - The common AV node reentry SVT is usually faster- >160 to 225. Again, there are exceptions, some ectopic atrial tachycardias and junctional tachys can be in the range we are seeing on this ekg but they are uncommon
- Atrial flutter with 2:1 block - Remember that the rate of the atrial mechanism is usually right around 300. So, flutter with 2:1 is going to be right around 150.
The first thing I think about with a regular rhythm, with a narrow QRS and a rate between 140 and 160 is atrial flutter. Then when you are expecting it you can take calipers and march thru flutter waves to confirm it. In this ekg easiest for me to track the "up" in Vl or the "down" in II but remember that the QRS often hides (sits on top of) one or the other in some of the leads.
This is atrial flutter with 2:1 block.
