Adult Tachycardia with a Pulse Flashcards
What your underlying goal with any ACLS situation?
Identify and Treat underlying causes:
- 5 H’s and 5 T’s, even if not cardiac arrest. So order a slew of labs.
- Supp O2 if hypoxemic
- Monitor vitals and often get a 12-lead EKG
- Often obtaining further IV/arterial/central access, and may place advanced airway if not in place
- Often would consult cardiology
How fast of a HR to make you suspect a tachyarrhythmia vs just Sinus Tach?
≥ 150 bpm
Two main successive branch points in Adult Tachycardia with a Pulse algorithm (ie, what two things, in order, do you ask yourself as you go down the algorithm to select the correct treatment)?
1) Hemodynamically UNstable?
- If yes pt is unstable, the answer is synchronized cardioversion (except if it is regular and narrow, in which you’d consider adenosine). Really take this in - any UNstable tachycardia WITH A PULSE - whether regular or irregular, wide or narrow QRS complex, or monomorphic or polymorphic QRS - gets a SYNCHRONIZED cardioversion.
- The only sort of exception for a tachycardia with a pulse that would get an UNsynchronized shock/defibrillation instead of a Synchronized cardioversion is an UNstable, WIDE QRS complex, POLYmorphic tachycardia, since it’s likely polymorphic VT and is probably just about to spiral into a VF or a pulseless VT, which is a cardiac arrest, which would be treated with an UNsynchronized defibrillation.
2) Pt is hemodynamically stable (HDS), but is the QRS WIDE?
- If QRS is WIDE, the answer is an antiarrhythmic infusion, or if refractory to antiarrhythmic infusion you’d cardiovert vs. shock/defibrillate (except if the wide QRS rhythm is clearly regular and monomorphic so you’re positive it is SVT with aberrancy [ie, SVT with a BBB], in which you’d consider adenosine)
- If QRS is NARROW, it’s AV node inhibition (Vagal maneuvers or adenosine) to diagnose or treat it, or Rate control (CCB or BB), and maybe Amio depending if regular or irregular.
- Regular vs Irregular R-R is the third branch point on a different card
3rd branch point to consider in adult Tachycardia with a Pulse algorithm to consider every time
Regular vs Irregular rhythms. Applies to narrow AND wide QRS tachyarrhythmia branches
S/S of a hemodynamically UNstable tachyarrhythmia?
Persistent Tachyarrhythmia causing:
1) HoTN
2) AMS
3) S/S of Shock
4) ACS (ischemic chest pain, EKG s/s)
5) Acute CHF
Standard Tx of hemodynamically UNstable Tachyarrhythmia?
Synchronized Cardioversion. Treat unstable SVT with immediate synchronized cardioversion, except in one specific instance may try something else (different card)
If a hemodynamically UNstable tachyarrhythmia is refractory to a synchronized cardioversion, what are your next tx options?
1) Increase energy level of next cardioversion
2) Add an anti-arrhythmic infusion
3) As always, work up underlying causes (5 H’s and T’s, etc.) and probably seek expert consultation in the form of consulting cardiology
Synchronized Cardioversion - what are the Biphasic doses based on tachyarrhythmia tele tracing:
Narrow complex and regular (regular SVT): 50-100 J
Narrow complex and irregular (irregular SVT, eg Afib): 120-200J
Wide complex and regular: 100J
Wide complex and Irregular: Shock / Defibrillate / UNsynchronized at 200J
Giselle says they just use a high dose the first time for any cardioversion, maybe even the max dose possible on the defibrillator
Unstable tachyarrhythmia but the rhythm is regular and narrow (so a regular SVT) - what options for treatment
Synchronized cardioversion is always an option
Adenosine is the other option. This is the ONLY UNTABLE tachycardia (regular and narrow = SVT) in which Adenosine may be considered. NO other UNstable arrhythmias, including REGULAR and MONOMORPHIC VT, may be treated with adenosine! It’s only STABLE regular & monomorphic VT that may be treated with adenosine
What are the three types of tachyarrhythmias in which you may consider Adenosine? Rate and Rhythm characteristics to consider:
1) Hemodynamic Stability (stable vs UNstable)
2) Width of QRS (wide or narrow)
3) Overall Rhythm (Regular or Irregular)
4) QRS morphology (Monomorphic or Polymorphic) - only even mention if QRS is WIDE
REGULAR, NARROW complex tachycardia (regular SVT) when the patient is STABLE - this is the main category
REGULAR, NARROW complex tachycardia (regular SVT) when patient is UNstable
REGULAR, WIDE complex, MONOMORPHIC tachycardia (this is SVT with aberrancy [ie, SVT with a BBB]) when the patient is STABLE. However, this is hard to distinguish from just VT, and AMIO treats both SVT with aberrancy and VT, so just give amio!
For the most part, what two to four types of tachyarrhythmias are you really thinking about treating when you’re considering treating with Adenosine?
1) AVRT or AVNRT - adenosine is THERAPEUTIC
2) A-flutter - adenosine is DIAGNOSTIC
- big note: both of these are hemodynamically STABLE, NARROW complex, REGULAR tachycardias!
If the rhythm is hemodynamically STABLE, NARROW complex, BUT IRREGULAR, then it’s probably A-fib, and Adenosine doesn’t treat that so don’t give it!
The last two situations where Adenosine are applicable are definitely more rare but worth mentioning for completeness sake:
3) pt is hemodynamically UNstable, but the rhythm is for sure NARROW and REGULAR. Here the patient is lucky enough that you can try Adenosine first before a cardioversion
4) SVT with Aberrancy (an SVT with a BBB, so a WIDE complex QRS). This is hard to tell apart from VT, and amio treats both of them anyways, so just give Amio.
Simply think of the MOA of adenosine to remember what types of tachyarrhythmias it’s useful or pointless for: Adenosine’s MOA is to completely block conduction at the AV node! So it may be useFULL for tachycardias that begin ABOVE the AV node (eg, Aflutter, AVRT, AVNRT, and regular monomorphic wide-complex tachycardia that you suspect is SVT with aberrancy [aberrancy = BBB]), but will be useLESS for arrhythmias that start BELOW the AV node (which is basically any WIDE complex tachycardia, regular or irregular, other than SVT with aberrancy)
Benefit of Adenosine in a few types of HDS, narrow, regular tachycardia?
AVRT (one pathway involves AV node) or AVNRT (obvi involves the node): can be curative since adenosine blocks the AV node
A-flutter: blocks any atrial flutter waves from getting through AV node into a ventricular depolarization, so you see just the flutter waves. It’s DIAGNOSTIC for Aflutter, not therapeutic.
Adenosine dose for any type of tachycardia you’re using it for
6mg IV push and MUST FLUSH. Central access is definitely best
12mg IV push second dose
It just stops AV nodal conduction for like 12 seconds and patients are going to feel weird/bad. Then they come back.
What is the definition of a “wide complex” QRS
≥ 0.12 sec
Pt is hemodynamically STABLE, but the QRS is wide. What is the treatment?
1) Adenosine only if regular and monomorphic (so an SVT with a BBB causing a wide QRS). But this is hard to tell apart from stable VT, so just give AMIO since it treats both
2) Anti-arrhythmic infusion - Amio, Procainamide, or Sotalol.
Is Adenosine ok for someone with WPW (delta wave) and/or Asthma?
NO, it is not. It’s especially not ok if there is Afib + WPW.
WPW (Wolf-Parkinson White) is a specific form of AVRT. AVRT, WPW, and pre-excitation syndromes are all pretty similar terms. WPW has an accessory conduction pathway (ie, bundle of Kent) that bypasses AV node. The delta wave is an upsloping of the QRS initial upward part, but usually doesn’t widen the QRS enough to be a wide QRS.
It’s beyond my understanding, but somehow having an intact AV node prevents a WPW + afib patient from having the really fast afib atrial rates travel unopposed to the ventricles, which would otherwise degenerate into VF. Since Afib is sort of the deadliest part of this (the super fast rates), ANY TIME YOU SEE AN IRREGULAR TACHYCARDIA (whether narrow or wide), YOU SHOULD AVOID ADENOSINE!! Adenosine doesn’t treat Afib anyways, but it’s even worse than being ineffective - it could be deadly!
Quick note on treating SVT with aberrancy with Adenosine. “Aberrancy” is just a BBB, which causes a wide-complex QRS. Adenosine is fine for wide-complex arrhythmias, as long as it’s not irregular (ie, as long as there’s no Afib) and as long as it’s STABLE. That being said, SVT with aberrancy is difficult to distinguish from VT, and amiodarone is a fine treatment for either, so just give Amio!
Aflutter Treatments
1) Adenosine - diagnostic, NOT therapeutic. so NOT a treatment
2) Beta-blockers - slows it down which can be good, but wouldn’t do if it was UNSTABLE A-flutter (easy to remember since should always cardiovert in ACLS if unstable tachycardia)
3) Anti-arrhythmic to convert it (eg, Amio) - but Aflutter is pretty resistant to chemical conversion
4) Synchronized cardioversion - yes works, happens all the time
Hemodynamically stable, narrow QRS complex, REGULAR tachycardia - broad categories of treatment
AV node inhibition:
1) Vagal maneuvers (bare down, blow into syringe, cold water to face) - vagus-mediated AV node inhibition to break the SVT, or at least diagnose it
2) Adenosine - AV node inhibition
Rate control - probably try this second if Adenosine or vagal maneuvers failed to convert tachyarrhythmia:
1) BB’s - rate control. Less negative inotropy
2) CCB’s - rate control. More negative inotropy so worse with unstable pts
Hemodynamically stable, narrow QRS complex, IRREGULAR tachycardia - broad categories of treatment
Rate Control:
1) BB’s - rate control. Less negative inotropy
2) CCB’s - rate control. More negative inotropy so worse with unstable pts
Rhythm Control:
1) Amiodarone
Vagal maneuvers - method and MOA
Bear down, or blow through a straw or syringe. Stimulates vagus which inhibits AV node
Vagal maneuvers - which tachyarrhythmias does it treat?
Stable, narrow complex, regular tachycardia
More specifically, it treats SUPRAcentricular (starting above the ventricles) tachycardia that then travel THROUGH THE AV NODE to the ventricles. The AV node being blocked by CN X is the MOA of tachycardia ablation here.
Beta Blockers - list the common ones for tachyarrhythmias
For stable, narrow, regular tachycardia
For stable, narrow, irregular tachycardia
1) Esmolol
2) Metoprolol
consider AVOIDING BB’s in ASTHMA (block the beta receptors in lungs which can cause bronchospasm; opposite of the beta-agonist albuterol)
Esmolol - dose, and when to give
For stable, narrow, regular tachycardia
For stable, narrow, irregular tachycardia
0.5 mg/kg over 1min. May repeat. May start infusion at 50 mcg/kg/min
Metoprolol - dose, and when to give
For stable, narrow, regular tachycardia
For stable, narrow, irregular tachycardia
1-2.5mg IV. Repeat or double the dose after 2.5min
