EMS is dispatched to a "cardiac patient in distress".
On arrival paramedics are led to the bathroom where the patient is found sitting on a foot stool. He is conscious but appears acutely ill. Skin is pale and he is slumped over. He states that he feels weak.
Past medical history: High blood pressure, high cholesterol, valve surgery.
Medications: Numerous but his spouse can't locate them. When the patient is asked for his medication list he states, "Ask my wife."
Vital signs:
- RR: 18
- Pulse: Rapid and weak
- NIBP: 85/53
- SpO2: 99 on RA
Breath sounds: Clear bilaterally.
Cannon waves are noted at the patient's neck.
The cardiac monitor is attached.
A 12-lead ECG is captured (retrieved here from the LIFENET).
What is your impression of the patient's ECG?
How would you treat this patient?
PST
Adenosine
Agreed SVT or the new term AVNRT. Vagal maneuvers adenosine.
Given the heart rate and regular/narrow appearance I would lean towards SVT as well. There is no substitute for a good history. If the patient/wife does not know where the medications are located I would ask them questions about "history of an irregular heart rate", use of medications like Digoxin, etc. I am not an expert on cannon waves, but I know that they are present in atrial fibrillation, not sure about SVT. I would also want to determine time of onset.
There is also no substitute for seeing the patient yourself. The case states he appears "acutely ill", he is slumped over, and hypotensive. Not sure about other "symptomatic" side effects like chest pain or dyspnea. Without seeing the patient for myself I would think he would be a candidate for immediate cardioversion. BP does not support pre-sedation and this appears to be rather time-sensitive. Also, not to dumb it down too much, but with this symptomatic appearance cardioversion would likely correct SVT AND atrial fibrillation. If you elected to attempt a chemical conversion with Adenosine and found you were dealing with an atrial fibrillation you would have lost time and potentially worsened the situation.
In short, I would likely elect to cardiovert in this case due to the patient's reported presentation. I would like to hear/learn more about cannon waves as without this being reported I be more confident in the use of Adenosine had the patient appeared more stable.
After reading the case my first instinct was adenosine, but I agree with Mike that cardio version is completely appropriate in this case.
History is very important. I would want to know if the pt is febrile. Elderly patients are prone to sepsis and we could be dealing with someone in septic shock. Fluid bolous as long as there is no signs of pulmonary edema if no immediate improvement then I would consider adenosine or cardioversion.
It’s fast, there are no visible P waves, but the QRS complexes are narrow, suggesting some kind of SVT. It’s lovely and regular, so I’m pretty certain it’s not fast AF.
Over here, treatment would be with diesel. He is hypoperfused, and has globalised ischaemic changes, so I would administer high flow O2 despite the SpO2. I would like a bit more history of how this all came on. Whilst it’s likely that the hypotension is due to the excessive heart rate, I wouldn’t yet rule out the possibility that the heart rate is due to trying to compensate for hypotension.
I would probably get the patient to perform vagal maneuvers, then transport. If I could get paramedic support, I would get them to consider fluids for the hypotension
Unstable SVT given the BP & general appearance, immediate synchronized cardioversion, then IV access & rapid transport, serial 12-leads en route.
Unstable, narrow complex tachycardia. Syncronized cardioversion, IV, oxygen, 2nd 12-Lead after conversion (if converted), followed by supportive care based on outcome and continued presentation.
junctional tachycardia possibility?
There's visible P waves…but after QRS, in lead V1, Inferior leads also seems to have inverted P , which could point to atrial flutter with a atrial rate of 340, so it would be F waves. This pattern could show the counter-clockwise rotation of the reentry circuit in a flutter.
Altough this, there also seems to be the same P waves in lead I, aVL and aVR, so I would bet in a SVT. Watch one little but strong detail: ST elevation in aVR, this suggest a SVT, not with a reentry circuit from 2 pathways in the AV node, bue a SVT with a AV acessory path, which in this case increases the concern about cardioversion, and look for delta waves after sucessfull cardioversion.
Plus: the last QRS seen in leads aVR, aVL and aVF. It's a fusion beat, and look how the qrs appears to mimic a delta wave!
I think there are visible P-waves. They are retrograde (following the QRS-complex). Still an unstable tachycardia, and all unstable tachycardias warrant sedation & immediate synchronized cardioversion.
What are Cannon waves? Cardiovert for the SVT, pre-pair for possible switching to VF. Try for more hx
Cannon waves are observed in jugular veins of the neck. They are produced by the R atrium contracting against a closed tricuspid valve, it indicates AV dys-synchrony. It could be that the SA node is firing at its usual rate or that there is retrograde conduction (p waves present in V1 with a short RP interval), which is what I am assuming.
Anyhow, I'd vote for a quick 6mg of adenosine if an IV can be established quickly before sending him on a lightning ride. I assume that a vagal maneuver won't work as it doesn't work more than it does, and he probably doesn't have the strength to do it properly, anyways; but, it actually could cause harm by impeding preload and worsening cardiac output potentially to the point of no cardiac output at all.
Some etomidate pre cardioversion if the adenosine doesn't work.
Looks like a SVT to me. I would go with 15lpm/NRB, IV, Monitor, Vagal Manuvers first…then 6/12/12 Adenosine. Can't Sync Cardiovert in my system as an I.
Id say junctional tachycardia, Im more of a medicine before edison guy, thus Id try the 6/12/12mg of adenosine first and likely transport due to my short transport times in my system and leave the cardioversion to the hospital where I would have plenty of people around when he codes after getting shocked.
Taking the emergency to the emergency room is not always the answer. The patient is obviously unstable and even a short ride to the er can be life threating.
It does look suspiciously like a junctional reentrant rhythm (retrograde Ps) and is obviously symptomatic so o2, bolus, vagals, adenosine, joules etc. I'm more curious though about the wide spread ST depression with elevated ST segments in aVR… could be rate demand ischemia? or does the history of a valve replacement make us wonder about some type of left main disease (perhaps a proximal aortic dissection or aortic valve issue either of which could cause issues for the opening of the LMCA) ?
Looking at this and it does appear to be a SVT, and I would consider this patient to be untable, and given the presntation he is in acute distress. I would attempt IV access, and immadite sync cardio vert. Yes, history is very important, but when a patient is presenting in this manner, you have to act and act fast., before they go down hill.
Def cardiovert. Hypotensive, SVT, distress, I would skip adenosine and go straight to cardioversion (given no hx of afib/flutter of course). If the patient presented differently, more appropriate blood pressure and less ill complaint, I may use medication therapy, but this is cut and dry in my opinion, as with mike, yes… Cardiovert.
And as a side note, are services still using old ACLS on adenosine administration? I know new ACLS cut out the extra 12, and our current protocols are now using the 6 and 12 only. Anyone else still using the full 30mg?
it's SVT because it's narrow complex tachycardia >150 and it's unstable because the pt is showing s/s of shock: pale skin, lethargy, hypotension.
the protocol here for unstable SVT is
o2, iv, synchronized cardioversion (before you fk with a 12 lead) @ 120J then 150J then 200J.
we have an option to premedicate with 5mg Valium, but not this guy.
vagal maneuvers and adenosine are for stable narrow complex tachycardia,
also, that's not junctional. there's no p waves at all. that's SVT.
ryan, there are p waves, they are just retrograde (after the qrs)
in additon there are cannon waves
this is not svt, but svt rx will/may still work. cardioversion is best here, supported by dis-sync as observed by cannon waves
Ryan/Harrison,
I would add that SVT is a blanket term for any tachycardia originating above the ventricles, encompassing junctional/nodal rhythms and atrial tachyarrhythmias. Thus SVT is appopriate for most narrow complex tachycardias believed to not be sinus in origin.
Moreover, the classical SVT definition of >150 is a bit outdated and should be replaced with an age based (or as Rogue Medic would rather you do it, P-wave based) measure of "fast". Using "220 – age in years" is a decent estimator of maximal sinus rates. For this gentleman, "fast" would be predicted to be ≥140.
I would have to agree with Chris, SVT is an all encompassing term for many rhythms. For this rhythm the prescence of P waves is inconclusive to me, they are not present in any of the "V-leads" This leads me to call this A-Fib. For me this is supported by the presence of the Cannon waves and the hx of valve surgery. Mitral/Tricuspid regurge is a common cause of A-Fib, this may have been corrected with his previous surgery however, after this event he may be in need of a redo depending on how old his valve is and if it is still functioning appropriately. I think his hypotension is rate related, if it is A-Fib his preload is going to be diminished already and now throw in increased rate and his cardiac output will be significantly decreased. Regardless of all of this, he is unstable based on BP and clinical appearance leading us to sync-cardiovert. Hopefully he hasnt had this A-Fib for awhile (and if it is preexisting hopefully he is med compliant with his Coumadin) otherwise we could be showering the brain/lungs with clots but I think we have to take our chances based on his current status. O2, IV x2, Cardiovert, consider a fluid bolus if needed, and transport ASAP.
I can't agree with CCTMedicRN, (probably) retrograde P-waves are visible in V1 and V6. And it's not A-fib since it's completely regular – except an aberrant beat as the last in the augmented leads (aVR..) which is a tiny bit too early and wider but seems to have roughly the same electrical axis.
If it's some sort of nodal dependent tachycardia then adenosine or cardioversion would restore it. But does anyone think this could be a ectopic atrial takycardia?
You know I never would have thought to use SVT as a blanket response for every rhythm that's not NSR that originates above the ventricles but it does make perfect sense! If I had to be exact, however, I would definitely call this rhythm Accelerated Junctional Tachycardia. There are P-waves all over that 12 lead: retrograde in III and AVF and upright in leads aVR, aVF, v1, and v2. This guy's signs and symptoms are probably due to his rate. 02 via NRB, capnography, IV x1 while looking for a second. Since his lungs are clear, IV wide open to titrate his BP to either 90 or 100. I'd be looking to cardiovert this guy right away. If I had a second ALS provider on scene I'd be looking to give this poor guy some Versed. Package him sitting comfortably and possibly in trendelengerg. I'd be hitting the road looking to contact our med control. I'd take the time in the back of the unit to do some quick dosage calcs for Dopamine or something in case electricity doesn't work.