Tachycardia/tachyarrhythmia is defined as a rhythm with a heart rate greater than 100 bpm.
An unstable tachycardia exists when cardiac output is reduced to the point of causing serious signs and symptoms.
Serious signs and symptoms commonly seen with unstable tachycardia are: chest pain, signs of shock, SOA (short of air), altered mental status, weakness, fatigue, and syncope.
One important question you may want to ask is: “Are the symptoms being caused by the tachycardia?” If the symptoms are being caused by the tachycardia treat the tachycardia.
Causes
There are many causes of both stable and unstable tachycardia and appropriate treatment within the ACLS framework requires identification of causative factors. Before initiating invasive interventions, reversible causes should be identified and treated.
The most common causes of tachycardia that should be treated outside of the ACLS tachycardia algorithm are dehydration, hypoxia, fever, and sepsis. There may be other contributing causes and a review of the H’s and T’s of ACLS should take place as needed.
Click below to view the H and T’s table. When done click again to close the diagram.
H’s and T’s Table
Administration of OXYGEN and NORMAL SALINE are of primary importance for the treatment of causative factors of sinus tachycardia and should be considered prior to ACLS intervention.
Once these causative factors have been ruled out or treated, invasive treatment using the ACLS tachycardia algorithm should be implemented.
Associated Rhythms
There are several rhythms that are frequently associated with stable and unstable tachycardia these rhythms include:
- Supraventricular tachycardia (SVT)
- Atrial fibrillation
- Atrial flutter
- Monomorphic VT
- Polymorphic VT
- Wide-complex tachycardia of uncertain type
ACLS Treatment for Tachycardia
Click below to view the tachycardia algorithm diagram. When done click again to close the diagram.
Tachycardia Diagram
or Members Download the Hi-Resolution PDF Here(This will open in another window.)
The first question that should be asked when initiating the ACLS tachycardia algorithm is: “Is the patient stable or unstable?” The answer to this question will determine which path of the tachycardia algorithm is executed.
Unstable Tachycardia
Patients with unstable tachycardia should be treated immediately with synchronized cardioversion. If a pulseless tachycardia is present patients should be treated using the cardiac arrest algorithm.
The AHA no longer provides specific shock dose recommendations for synchronized cardioversion. Instead, they instruct to refer to your specific device’s recommended energy level to maximize first shock success.
For the purposes of a basic understanding of cardioversion, the information about general shock dosages and recommendations will remain in the content on this website.
The initial recommended synchronized cardioversion voltage doses are as follows:
- narrow regular: 50-100 J; i.e., SVT and atrial flutter
- Narrow irregular: 120-200 J biphasic or 200 J monophasic; i.e., atrial fibrillation
- Wide regular: 100 J; i.e., monomorphic VT
- Wide irregular: defibrillation dose (not synchronized)
Stable Tachycardia
Patients with stable tachycardia are treated based upon whether they have a narrow or wide QRS complex. The following flow diagram shows the treatment regimen for stable tachycardia with narrow and wide QRS complex.
- Stable (narrow QRS complex) → vagal maneuvers → adenosine (if regular) → beta-blocker/calcium channel blocker → get an expert
- Stable (wide/regular/monomorphic) → adenosine → consider antiarrhythmic infusion → get an expert
John Hileman says
One more question: If it is unstable, wide complex, irregular, tachycardia, don’t we go to defibrillation, unsynchronized?
Jeff with admin. says
Yes. Use defibrillation. The “wide” and “irregular” is why you use defibrillation. The defibrillator will most likely not SYNC with the wide irregular tachycardia and immediate defibrillation is indicated. See page 162 AHA Manual in the gray box to the right 4th bullet point.
John Hileman says
I’m sorry, I’m just a Paramedic candidate (taking the NR soon). But I must be having a major brain-fart. I don’t recall “TEE”. Unrelated to golf, I assume. Please refresh my memory!!
(I’m guessing this is a procedure or monitoring method only available in-hospital?)
Jeff with admin. says
Hi John,
“TEE” means — Transesophageal echocardoigram
Beth says
What about getting expert consultation first with irregular tachy- in case there’s a clot
Would you cardiovert a fib without a TEE?
Chris with admin. says
ACLS guidelines recommend synchronized cardioversion for patients with unstable irregular tachydcardia; however, there are times when that would be the wrong thing to do. Here’s an example: 64 yr old female with a known history of Atrial Fibrillation is admitted to the ICU for septic shock. She is hypotensive and tachycardic (155bpm), pale, cool and diaphoretic to 155. In this case the correct thing to do would be to volume resuscitate. So, you are correct that the situation and your clinical judgement rule out using the ACLS guidelines in this case.
If the patient is admitted with a privmary diagnosis of unstable atrial fibrillation 48 Hrs. there is a worry that the patient may have developed clot. heparinization would be indicated. TEE would be a good idea. Expert consultation is always adivsed.
I hope this helps.
Best Regards, Chris
Dana Maes says
It is nice to have such straight forward information at hand.
sandra horvath says
three of the 6 rthyms were down No information on those. I would expect better for what I paid for.
Jeff with admin. says
If the tachycardia is wide-complex and UNSTABLE it should be treated with synchronized cardioversion first.
stella says
Thank you so much for the information. I am scheduled for Mega Code tomorrow, very nervous now.
Christine Thurman says
Jeff and Chris: Thanks so much for this site. Just took my new 2011 ACLS, my instructor
said the class north of us had disastrous results 80% failed! Thanks for so much on capnography, there were at least 3 questions on that. I passed 98%. The megacode
really burned things into my mind!!!
Mikaela says
Great learning, thx everbody for shering this , it helps me a lot.
berylprem says
Exclent learning website for the guys in medical emergency , sharpens ones skills in handson emergency practice .its practical and challenging task.
belinda smith says
Jeff, can you please explain to me what is the difference between a stable and an unstable tachycardia? Does it have to do with the disposition of the patient or is it a rhythm? Love the website! Tons of great information. Thanks.
jeff with admin. says
Belinda,
Unstable Tachycardia will involve serious signs and symptoms that are caused by the tachycardia. Examples are hypotension, acutely altered mental status, signs of shock, ischemic chest discomfort. Also, most of the time, unstable tachycardia will have a rate that is greater than 150 beats per minute.
Stable tachycardia will may involve some signs and symptoms but they will not be serious. Usually stable tachycardias will be less than 150 beats per minute.
MAAN says
thank for all this inf it Improve type of ACLS caring
omar khateeb says
Awesome website. The only missing piece (which seems to be coming soon) is the wonderful ACLS algorithm diagram
jeff with admin. says
These are coming soon.
David says
Thanks for this website, it has been invaluable!
sonia cannistraci says
love your website, thanks. can u let me know when the information for Tachycardia Algorithm is completed. 🙂
arya says
all pages are improve my skill in ACLS