EKG
Ventricular Tachycardia Management in the Adult
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Ventricular Tachycardia Management in the Adult
, Torsades de Pointes, Torsades
See Also
Ventricular Tachycardia Management in the Child
Unstable Tachycardia
Narrow Complex Tachycardia
Wide Complex Tachycardia
Indications
Wide Complex Tachycardia
in Adults
Tachycardia
(typically >150 bpm) AND
Wide
QRS Complex
(duration at least 0.12 sec)
Precautions
SVT with aberrancy
Manage
Wide Complex Tachycardia
as
Ventricular Tachycardia
Algorithms (e.g. Griffith,
Brugada
, Bayesian) are inadequate
Cannot distinguish VT from SVT with aberrancy (or
RBBB
) - miss rates of 6-7% at best
Jastrezbski (2012) Europace 14(8): 1165-71 [PubMed]
Szelenyi (2013) Acad Emerg Med 20(11): 1121-30 [PubMed]
Consequence of treating
Ventricular Tachycardia
as SVT (e.g. with
Calcium Channel Blocker
) can be lethal
In contrast, treating SVT with aberrancy with an
Antiarrhythmic
(e.g.
Procainamide
) is unlikely to cause harm
Adenosine
use in
Wide Complex Tachycardia
is also controversial
Ventricular Tachycardia
will convert to sinus rhythm with
Adenosine
in 5-10% of cases
Conversion with
Adenosine
leads to incorrect conclusion that the underlying rhythm was SVT with aberrancy
May result in missed VT diagnosis
Misses associated telemetry admission,
Antiarrhythmic
s and electrophysiology evaluation
Amal Mattu recommends not using
Adenosine
in
Wide Complex Tachycardia
Risk of masking potentially lethal VT in up to 10% of cases
References
Mattu in Herbert (2014) EM:Rap 14(7): 4-5, 13-14
Approach
Gene
ral
ABC Management
with IV-O2-Monitor is paramount in all cases
No pulse
Treat as
Pulseless Ventricular Tachycardia
Unstable (
Hypotension
,
ALOC
, ischemic
Chest Pain
or acute CHF)
Treat as Unstable
Ventricular Tachycardia
Administer
Synchronized Cardioversion
Stable
Assess
QRS Complex
morphology
Treat per protocols below
Monomorphic
Ventricular Tachycardia
Polymorphic
Ventricular Tachycardia
Approach
Wide Complex Tachycardia
(key question is 'regular or irregular')
Unstable
Wide Complex Tachycardia
Synchronized Cardioversion
(or asynchronized,
Defibrillation
if not responding)
Stable
Wide Complex Tachycardia
(see each approach described in sections below)
Irregular
Wide Complex Tachycardia
Regular
Wide Complex Tachycardia
Approach
Irregular
Wide Complex Tachycardia
(stable)
Polymorphic
Ventricular Tachycardia
INITIAL Steps
Immediate
Defibrillation
(non-
Synchronized Cardioversion
)
Differentiation based on
QT Interval
is directed at prevention of recurrent
Arrhythmia
Prolonged QT
interval (on baseline EKG): Torsades de Pointes
Give
Magnesium
2 grams IV
May be repeated in 5-15 minutes
May be continued as infusion
Magnesium
3 to 20 mg/min IV for
Prolonged QT
c
Correct other
Electrolyte
abnormalities (
5H5T
)
Stop all medications that prolong
QT Interval
Reverse toxic ingestions and
Poisoning
s
Consider overdrive pacing to
Heart Rate
of 100 bpm
Avoid
Isoproterenol
(used historically)
Normal
QT Interval
(on baseline EKG)
Myocardial Ischemia
(most common)
Beta Blocker
s
Emergent cardiac catheterization for revascularization
Consider
Amiodarone
150 mg IV
Catecholamine
rgic
Ventricular Tachycardia
Consider
Beta Blocker
s
Brugada Syndrome
Consider
Isoproterenol
Pre-excited
Atrial Fibrillation
(antegrade conduction via accessory pathway, e.g. WPW)
Avoid AV Nodal blockers (
Beta Blocker
s,
Diltiazem
,
Verapamil
,
Digoxin
,
Adenosine
)
Consult with local experts
Rapid
Heart Rate
typically requires electrical cardioversion
Consider
Amiodarone
150 mg IV
Atrial Fibrillation
with aberrancy
Treat as
Narrow Complex Tachycardia
only if can rule-out pre-excited
Atrial Fibrillation
Approach
Regular
Wide Complex Tachycardia
(stable)
INITIAL:
Adenosine
(or go to below under
Ventricular Tachycardia
)
AVOID if polymorphic or irregular
Wide Complex Tachycardia
(can degenerate to VF)
Some experts recommend avoiding
Adenosine
in all cases of
Ventricular Tachycardia
(see precautions above)
Dose: 6 mg IV (may repeat with up to two 12 mg IV doses)
Effect
SVT (or aberrancy): converts or at least slows rhythm for interpretation
VT: no effect (unless irregular, in which case could degenerate into VF)
Ventricular Tachycardia
(assume until proven otherwise)
Synchronized Cardioversion
if unstable or refractory to measures below
Recommended agents for chemical cardioversion
Procainamide
Preferred if not contraindicated
Zipes (2006) Circulation 114(10): e385-484 [PubMed]
AVOID in
Prolonged QT
or CHF
Loading Dose 50 mg/min
Target: Until successful,
Hypotension
, or QRS widens >50%
May slow rate to 20 mg/min (or stop and restart slowly) if
QRS Widening
or
QT Prolongation
occurs during infusion
Maximum: Cummulative dose 17 mg/kg (or ~1 gram)
Maintenance: 1-4 mg/min
Post-cardioversion
Antiarrhythmic
infusion may be replaced with
Beta Blocker
instead (see below)
Amiodarone
Preferred in CHF or
Prolonged QT
(but effective in only 20% of cases)
Dose 150 mg IV over 10 minutes
Maintenance: 1 mg/min for 6 hours
Post-cardioversion
Antiarrhythmic
infusion may be replaced with
Beta Blocker
instead (see below)
Sotalol
AVOID in
Prolonged QT
Dose 1.5 mg/kg up to 100 mg over 5 minutes
Post-Cardioversion (chemical or electrical) management
Beta Blocker
(
Metoprolol
or
Esmolol
)
Consider starting after successful cardioversion (not before due to negative inotropy)
Suppresses
Ventricular Tachycardia
associated
Catecholamine
surges
Consider in place of
Antiarrhythmic
infusions listed above
References
Mattu in Majoewsky (2013) EM:Rap 13(9): 7
Cardiopulmonary Resuscitation
Guidelines
http://www.circulationaha.org
(2010) Guidelines for CPR and ECC [PubMed]
(2000) Circulation, 102(Suppl I):86-9 [PubMed]
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