AM Report Pearls: Approach to Ventricular Tachycardia – Diagnosis:
- Stable or unstable? If unstable (hypotension, chest pain, or altered mental status), proceed with ACLS and assume it’s VT!
o In general, if patient is unstable, assume it’s VT, and if patient is stable, you have more time to figure it out & is more likely to be SVT BUT you can be fooled with slow VT!
- Any risk factors for VT?(e.g. Prior MI, prior cardiac surgery, known scars)? If so, assume it’s VT!
- Do they have a prior EKG with an old LBBB or old RBBB?If the patient is stable AND has an old bundle branch block, more likely to be SVT with aberrancy
- Check for capture or fusion beats: If these are present, it’s VT. these beats have the highest positive predictive value for VT.
- Check for A-V dissociation: A-V dissociation is not required for VT, but is strongly suggestive
- Check for concordance: Look for concordant morphology in leads V1-V6 (i.e. all negative or all positive)
- R wave in aVR present aka “Up in aVR”? This is the Vereckei criteria which is a quick tip for seeing if VT as well!
- If you’ve made it this far, patient is stable, and still not sure, now you can bust out Brugada criteria!
For more reading if you are a true Cardiology nerd, I recommend ECGPedia.org – this article is a good one! http://en.ecgpedia.org/wiki/Approach_to_the_Wide_Complex_Tachycardia#Vereckei_aVR_algorithm_.5B5.5D
AM Report Pearls: Approach to Ventricular Tachycardia – Management:
- As above, first check if stable or unstable, if unstableàACLS protocol
- If stable, see if sustained (>30 seconds) or non-sustained VT (<30 seconds) on EKG
- Assess via TTE if heart is structurally normal or not
- Evaluate all patients with VT for ischemia since majority of patients with VT and structural heart disease have CAD
- EP studies are not recommended if clear diagnosis of VT by EKG and if you are already planning on ICD placement
- There is a mortality benefit in using AICDs in patient with recurrent VT/VF
- Antiarrhythmic drugs can help treat patients with symptomatic VT and can reduce incidence of ICD shocks in patients with AICD
o Most common drugs are IV/PO amiodarone and PO sotalol (both class III antiarrhythmics that prolong the action potential duration) and IV lidocaine (class IB) – choose the drugs according to risks/benefits & route of entry
o The AVID trial of secondary prevention showed that dual ICD+anti-arrhythmic drug therapy reduced arrhythmias
o SCD-HeFT trial showed that amiodarone did not reduce mortality in patients with VT and reduced EF as opposed to ICD or placebo – ICD is preferred to amio alone
o Note that sotalol is renally cleared – caution!
- Class I Indications for AICD placement for VT:
o Post-arrest patients with VFib or unstable VT
o Patients with structural heart disease AND spontaneous sustained VT, whether stable OR unstable
o Patients with symptomatic hemodynamically significant sustained VT or VF induced on EP study
o Patients with nonsustained VT due to prior MI + EF < 40+ inducible VF/VT on EP study
o For all indications for AICD, please check out the latest guidelines at http://circ.ahajournals.org/content/117/21/2820.full