I chuckled a little when I saw that monitor said the rate was 85. The rate is clearly close to 300.
It is a regularly regular narrow complex tachycadia. I believe it is an SVT.
Types of SVT
- sinus tachycardia
- atrial fibrillation
- Atrial flutter
- AVNRT
- accessory pathway mediated tachycardia
- atrial tachycardia
- multifocal atrial tachycardia
- junctional tachycardia
I kinda forget the order of most to least common, but it is something like that.
The whole 220-age for upper sinus tachycardia rate is a good guideline, but not a rule. This is obviously well beyond even 220... probably not sinus tachycardia.
The rhythm looks regularly regular to me, but it is possible that the rate is making it look regular. At such a high rate it is hard to tell sometimes. I would say about 300 is still too high for atrial fibrillation.
Oddly, I think the monitor may be right about atrial flutter even though it is totally wrong about the rate. The rate is just about right for an atrial flutter rate 300 (I consider around 250-350 normal. Some literature say 200-400). Since this is about 300 that would make 1:1 atrial flutter pretty high on my differential. This would also explain the very odd looking ST changes and concordancr of those changes because the flutter waves would be superimposed on top of the complexes and T wave. The oddball thing to me is where I see the flutter waves best. Typically atrial flutter is best seen in the inferior leads (II, III, and aVF) and lead V1. I also usually see it in lead aVR (due to it being opposite of lead II). On this ECG, I see it on almost every lead.
Note atrial flutter and atrial tachycardia are pretty similar, but the atrial rate is slower (150-250 instead of 250-350). Both can have variable blocks which is not present here.
AVNRT is still a possibility. The most common form (slow-fast) will have an pseudo s wave in III and pseudo RBBB or pseudo r wave in lead V1. The less common types of AVNRT will make a double hump in the T wave or even look like sinus tachycardia with a 1st degree block.
At a rate of 300, an accessory pathway mediated tachycardia is definitely a possibility.
Like atrial fibrillation, multifocal atrial tachycardia is an irregular rhythm.
Junctional tachycardia is the rarest making it least likely. This goes up my differential if the patient is taking digoxin.
Another possibility is VT (it looks wide in some leads and the widest lead, longesr QT, longest PRi, etc. are what you use). I believe the leads that are wide are due to the ST changes or superimposed flutter waves. A narrow form of SVT is fascicular VT. It'll have a RBBB morphology, which this does not have, and the most common form of fascicular VT has left axis deviation, which this does not have. This is more inferior axis or around +90 degrees.
There is really nothing else I can add in regard to interpretation. I would call it an SVT. I think 1:1 atrial flutter is most likely.
I would follow AHA guidelines. If the patient was hemodynamically stable then I would establish and line and administer fluids. I would attempt to the have the patient vagal down if the IV didn't do the trick. I would administer adenosine. If that didn't work then I would sedation with synchronized cardioversion. I would be concerned about the monitor approproately recognizing the QRS complexes.
If he was hemodynamically unstable then I would immediately do synchronized cardioversion. 1:1 atrial flutter is not tolerable for long and the patient will probably be hemodynamically unstable. Arrial flutter does respond well to electricity I believe.
If we didn't go all the way to cardioversion and the patient was stable, then I would expect the hospital to administer a Ca2+ channel blocker like diltiazem or cardiovert the patient themselves.
