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Ventricular Tachycardia: Management 1457

Ventricular Tachycardia: Management
VetBooks.ir Electrocardiographic (ECG) rhythm consists

only of wide, bizarre QRS complexes

Is the rate high?
• 160 bpm for giant-breed dog
• 180 bpm for small-breed dog
• 240 bpm for cat
No Yes

This is not ventricular tachycardia (VT): Is there a P wave for every QRS and is
• Ventricular escape rhythm the PR interval constant?
• Accelerated idioventricular rhythm
• Motion artifact No to either or both No to either or both Yes to both
• Sinus rhythm plus conduction defect
such as right bundle branch block
VT Atrial fibrillation or This is not VT.
flutter, plus right Consider:
bundle branch block • Right bundle branch
Do not treat with antiarrhythmics Are there clinical signs (rare) block
directly attributable to • Another conduction
the arrhythmia? defect
• Syncope
• Other (present when Treat accordingly
arrhythmia is present;
gone when it is gone)
Yes No

Treatment is indicated. Is there an underlying problem that may be triggering
Options include: the VT and that must be dealt with first?*
• Intravenous (IV) • Hypoxemia (congestive heart • Intoxication
Lidocaine failure [CHF], other) † • Excess
• Oral (PO) • Anemia (packed cell catecholamines
Sotalol volume 25%) † • Structural heart
Mexiletine plus • Hypokalemia † disease †
beta-blocker • Hypomagnesemia • Myocarditis
• Sepsis (diagnosis by
• Acidosis exclusion)
• Abdominal mass † • Gastric dilation/
• Blunt trauma † volvulus (GDV) †
Yes No (or is being corrected)

Address the underlying Is rate sustained at greater than
problem first parameters above?
Is pulse quality (or measured blood
pressure) suboptimal? Clinical Algorithms
Yes to either or both No to both

Treatment is indicated. Reassess but no
Options include: antiarrhythmic
• Intravenous (IV) treatment for now
Lidocaine
• Oral (PO)
Sotalol
Mexiletine plus beta-blocker
Tocainide plus beta-blocker
Amiodarone
*Virtually any medical problem, if severe enough, can cause ventricular arrhythmias.
† Most common.
(Modified from Ettinger SJ, Feldman EC: Textbook of veterinary internal medicine, ed 8, St. Louis, 2017, Elsevier.)

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