Is It Physiologic or Cardiac?

So on my first day back I discussed with my budding paramedic partner (I promised not to mention Bobby’s name or anything… oops…) issues surrounding ACLS and what he is/was being taught about tachycardia. He was attempting to present the position that any rhythm with a rate above 160 in adults must therefore be supraventricular tachycardia and must absolutely be treated with anti-dysryhthmics or synchronized cardioversion.

Rookie mistake.

It turns out the discussion arose during a call he made while I was off, with my other counterpart. It was a hot day, and a mailman had been walking his route and collapsed. When they arrived, they found the man with a heart rate in excess of 170. Classic heat stroke, but looking at the just the strip, my soon to be medic partner classified it as an SVT.

Technically, he is correct, but his mindset for treatment was very, very wrong. What I spent the next 10 minutes explaining was that even though the rate was super fast, it was still sinus tachycardia. He was debating that the rate made made it SVT. I explained that SVT is a blanket term that describes ALL tachycardiac rhythms that originate above the ventricles, atrial fibrillation with rapid response originates above the ventricles, therefore it is SVT, as does sinus tachycardia. The rhythm isn’t necessarily dependent on the rate, a healthy adult can run 3 miles and have a heart rate at the end of 170 or 180 and it still be sinus tachycardia, but Mrs. Smith with a history of AF and a heart rate of 180 raises that index of suspicion that it may not be due to exercise.

What I am getting at is that in your thought process you should consider the REASON for the tachycardia. The mailman, for example, was an easy case. Being outside on a hot day, lack of fluid intake or a cool place to sit made the treatment options very clear with increasing intravascular volume and cooling him down passively to avoid cooking his brain. I have posted other cases before regarding SVT, which was a true cardiac case. When a tachycardia starts suddenly, with no extra factors and considering patient history, you should be leaning more towards treating a cardiac problem.

So is it cardiac, or physiologic?

  • Pyroman347

    Well written!  Thanks for the reminder that we should treat the patient and not always the monitor.

  • Pyroman347

    Well written!  Thanks for the reminder that we should treat the patient and not always the monitor.

  • 68 Emu

    Goes back to the old adage… Treat the patient not the numbers

  • 68 Emu

    Goes back to the old adage… Treat the patient not the numbers

  • Too Old To Work

    Not only a rookie mistake, a potentially fatal rookie mistake. I might even have post on my blog about that, but I’ll recap here because I’m too lazy to search for the link.

    SVT is a lazy medics (or doctors, or nurses) term when they can’t or won’t determine what a rhythm really is. It might be Atrial Tach, Atrial Fibrillation, or Atrial Flutter. Or as you point out Sinus Tach. The rate or even the rate and exact rhythm are only part of the story.

    I’ve seen patients in sinus tachycardia as fast as 170, especially if they are in failure. If you cardiovert those patients, give the Adenosine, or God forbid, Beta or Calcium channel blocking agents you are running a risk of killing your patient.

    The easiest way to differentiate between CHF and cardiogenic shock is to look at the blood pressure. If the patient is tachycardic, has wet lungs, and is hypertensive, then you are likely dealing with CHF and need to attack the cause. Which means nitrates, maybe Lasix, but definitely CPAP. If the patient is hypotensive, tachycardic, and has wet lungs, they are in cardiogenic shock. Rate control might be the answer, but it depends on the rate and the rhythm. In that case, I’d try airway support and probably a pressor, especially if the rhythm looks to be sinus in nature, regardless of rate.

    ACLS is often simplistic in it’s approach to very complex problems. Good instructors can make a huge difference but new medics have to remember that that patients rarely present in as straightforward a manner as the text books would suggest.

    That’s why this http://circ.ahajournals.org/content/112/24_suppl/IV-67/F2.large.jpg is so complex.

  • Too Old To Work

    Not only a rookie mistake, a potentially fatal rookie mistake. I might even have post on my blog about that, but I’ll recap here because I’m too lazy to search for the link.

    SVT is a lazy medics (or doctors, or nurses) term when they can’t or won’t determine what a rhythm really is. It might be Atrial Tach, Atrial Fibrillation, or Atrial Flutter. Or as you point out Sinus Tach. The rate or even the rate and exact rhythm are only part of the story.

    I’ve seen patients in sinus tachycardia as fast as 170, especially if they are in failure. If you cardiovert those patients, give the Adenosine, or God forbid, Beta or Calcium channel blocking agents you are running a risk of killing your patient.

    The easiest way to differentiate between CHF and cardiogenic shock is to look at the blood pressure. If the patient is tachycardic, has wet lungs, and is hypertensive, then you are likely dealing with CHF and need to attack the cause. Which means nitrates, maybe Lasix, but definitely CPAP. If the patient is hypotensive, tachycardic, and has wet lungs, they are in cardiogenic shock. Rate control might be the answer, but it depends on the rate and the rhythm. In that case, I’d try airway support and probably a pressor, especially if the rhythm looks to be sinus in nature, regardless of rate.

    ACLS is often simplistic in it’s approach to very complex problems. Good instructors can make a huge difference but new medics have to remember that that patients rarely present in as straightforward a manner as the text books would suggest.

    That’s why this http://circ.ahajournals.org/content/112/24_suppl/IV-67/F2.large.jpg is so complex.

  • “listen, new guy…”

  • “listen, new guy…”

  • I got some good experience from bad judgement after my first cardioversion…

  • I got some good experience from bad judgement after my first cardioversion…