Adenosine given to Sinus Tach?

[waulen2980]

Hi All,

I'm a medical student and recently was at the ER doing observations. I have a question for EMT's:

Here is case:

27 Yr old male, otherwise healthy, brought into ER with what EMT's described as sinus tachycardia according to their EKG. The story was the individual said he had been out jogging and became alarmed at his high pulse rate. Max HR at 170 BPM, BP @ 135/74. He was given 6mg of Adenosine to slow HR which according to them; worked temporarily.

Once in ER, patient described no occurances of chest pains or shortness of breath at any time.

Blood work, chest x ray, and EKG, all normal.

Drug urinalysis- negative

Patient complained of constant waves of anxiety which precipitated an increase in HR of about 110-120. Ativan 1 MG was administered and condition improved significantly and discharge was made approx. 3 hours after arrival.

Sorry for the long story, I wanted to give the whole picture.

My question: Why was adenosine given to someone with aside from the fast heart beat, normal sinus rhythm?

My understanding is that Adenosine is primarily used for SVT alone.

[Arctickat]

Now, here we are in the correct forum.

1. Cookbook medics following the ACLS Algorithm without determining the cause of the Tachycardia and treating that.

2. And any narrow complex Tachycardia can be treated with Adenosine. BTW, Sinus Tachycardia is an SVT.

Honestly, I don't know that I'd have given either medication. You have a 27 year old male, conducting an aerobic exercise who gets anxious because his heart rate is in the target zone? Personally, I'd have told the guy that his heart rate is right where it should be and to continue running. The fact that he became anxious regarding his heart rate alone (I'm assuming he had one of those wrist monitors because there were no other S/S) indicates that this patient didn't comprehend the purpose of a target heart rate.

The adenosine worked temporarily, likely because the heart rate increase was not a result of anything cardiac, but because it was physiologically normal given the circumstances, then the anxiety attack exacerbated the tachycardia beyond the normal recovery duration from the exercise.

Edited July 3, 2012 by Arctickat

[croaker260]

My question: Why was adenosine given to someone with aside from the fast heart beat, normal sinus rhythm?

My understanding is that Adenosine is primarily used for SVT alone.

Adenosine may be used for a multitudeof tachy arrythmias, not simply "SVT". It is just most likely to be efective in the SVT/A-Tach side of the house. With the A-Fib/A-luter, adenosine is NOT contraindicated, it simply may not be as effective..or effective at all. What it MAY do ...emphasis on "May".... is allow some transient slowing to allow better assessment of the actual rythm.

Now, why the medics gave adenocard is really a question only they can answer. I would also wonder if they attempted vagal manuevers prior to the adenocard. I would assume (and we all know what an assumtion does) that the HR combined with a presumable diaphoretic, pale and SOB patient (remember he was just post running)..and a lack of critical assessment of the context of the situation may have contributed to the situation. I agree with Artickat..I doubt I would have given the patint any Rx if he was as your presented him. ...but who knows. I try not to get comfortable in the arm chair of the monday morining quarterback.

Please remember that patients seldom look the way they do inthe ER as they do on scene. Their stories change, their presentationas change, and often it is assumed (again with assumptions) that the medics were somehow dropping the ball. The reality is...medicine is a fickle , moody bitch that changes directions at a whim.

Edited July 4, 2012 by croaker260

[Arctickat]

Their stories change, their presentationas change, and often it is assumed (again with assumptions) that the medics were somehow dropping the ball. The reality is...medicine is a fickle , moody bitch that changes directions at a whim.

Oh how I can relate. So many times we get a history from the patient that is totally different from the one the nurse gets when we arrive at the hospital. Or, we assess the patient and find the broken leg..treat it appropriately, and once the pain meds take effect and the patient is in the ED we discover he also has a broken ulna that wasn't noticed by the patient because of the distracting pain and all our assessment noted was a bruise....sigh

[ERDoc]

170 may be this guy's target zone, but it is also in the SVT zone. Without seeing what the medics saw, it is hard to compliment/criticize. Maybe this guy was put into an SVT by his exercise and the adenosine did its job.

[waulen2980]

Thanks for the responses! Just want to be clear, I am not implying anything negative about EMT's with the question only fact-finding.

Also, I'm a little unclear about how EMT's are distinguishing SVT's from Sinus Tachycardia. If 170 BPM was automatically considered SVT, then would everyone who exercises an gets to 170 be having an SVT? I was taught it was distinguishable by the P-wave being present or not.

[Arctickat]

An SVT is a supra ventricular tachycardia. All that means is that the originating pacemaker is located above the AV node. Since a sinus beat originates above the AV node, it is an SVT, provided that it's a tachycardia of course. There are several types of SVTs, Sinus Tach is but one. ERDOC makes a good point that I was thinking but forgot to type. I wasn't there, I can only make a few assumptions which don't really include the whole story.

[waulen2980]

An SVT is a supra ventricular tachycardia. All that means is that the originating pacemaker is located above the AV node. Since a sinus beat originates above the AV node, it is an SVT, provided that it's a tachycardia of course. There are several types of SVTs, Sinus Tach is but one. ERDOC makes a good point that I was thinking but forgot to type. I wasn't there, I can only make a few assumptions which don't really include the whole story.

Ok, I see now. Thanks for explaining, I was confused about SVT and Sinus Tach. As per the patient in question, the whole episode he had was very similiar to the panic attacks I've seen in the ER. The only unusual circumstance is that he had one while exercising which according to internet literature, seems to be more common than I thought. I'm deducing this to be some sort of hypochondria episode involving the heart. Ahh psych, that's a whole other topic!

[Kiwiology]

Differentiating between ST and SVT can be difficult

I believe adenosine is restricted here to patients who have a known history of SVT that is responsive to it and it's an Intensive Care Paramedic medicine anyway so not overtly familiar with it

Oh if you want a psych project dude you found it right here *holds up hand, whoops can't let those dinner time valiums fall out lets just pick those up mmm nom noms

[ERDoc]

One way to figure out if this is a sinus tach due to exercise versus SVT is to wait a few minutes. If this is sinus tach from the exercising then the heart rate should go down relatively quickly. If it is SVT then time will have no affect and he will be a constant 170. With SVT there is also very little variation in the rate, it will be 170. With a sinus tach there will be some variability to the rate.