VT Storm

Brian Gilberti, MD, PGY-3
Follow-Up Rounds 3/3/2017

• 75 yo M
• PMH CAD s/p CABG, HFrEF (25%, AICD), HTN, DM
• Worsening over past two days
• Denied fevers, vertigo, CP, SOB
• Compliant with medications

STUDIES

Labs: Unremarkable
ICD Interrogation

• Episodes
  • Today: VT
  • 2 days prior: VT >18 hrs
  • 3 days prior: VT > 18 hrs

Definition

• Without ICD
  • ≥2 episodes of VT within 24 horus
  • Recurrence of VT within 5 mins of termination of prior episode
  • >24 hour episode
• With ICD
  • ≥3 episodes requiring device intervention
• Incidence 2-10% per year in patients with ICDs

Triggers

• Structural abnormality
• Myocardial ischemia
• Heart failure
• Thyrotoxicosis
• Hypomagnesemia
• Hypokalemia
• QT prolongation

Indicators of Ventricular Tachycardia on ECG (vs SVT with aberrancy)

• Regular
• Northwest axis (-90 to +/-180)
• Compared to sinus rhythm, axis shift >40 during wide-complex tachycardia
• QRS duration >160 msec
• Negative concordance of QRS morphology in V1-V6
  • Positive concordance as well, but not as strongly suggestive of VT
• Fusion beats (diagnostic of VT)

Treatment

• Unstable
  • Cardiovert
• Stable
  • Antiarrhythmics
    • Procainamide
      • Procainamide was more effective than Amiodarone in terminating VT within 20 mins (67% vs 38%) and had fewer MACE (9% vs 41%).¹
        • NB: This was not a study of pts with electrical storm
      • AHA Class IIa for stable monomorphic VT
      • Contraindicated in patients with impaired renal function because its active metabolite, N-acetylprocainamide, is excreted by the kidneys
      • Administer until:
        • Max dose of 17 mg/kg or 1 g
        • Arrhythmia resolves
        • QRS widens by >50%
        • Pt bradycardic
        • Pt hypotensive
    • Amiodarone
      • Reduces frequency of recurrent episodes of ventricular arrhythmia^2,3
      • Mexiletine/Purkinje catheter ablation⁴
        • Effective in relatively narrow QRS refractory to Amiodarone
      • Acute side effects⁵
        • Hypotension (diluent)
        • Bradycardia
        • AV block
        • QT prolongation
        • Interstitial lung disease/pulmonary fibrosis
        • Hepatitis
      • Lidocaine^6,7
        • Most efficacious in ischemic myocardium
        • Conversion rates from VT = 8-30%

Beta Blockers^6,7

• Provides competitive sympathetic blockade
• Metoprolol preferred
• Propranolol reasonable but no studies supporting the use of one over the other
  • Use with caution in patients with HFrEF

Catheterization⁸

• Electrical storm often seen in ischemic heart disease
• Urgent cath if MI considered etiology

Catheter Ablation^6,9

• Recommended if VT persists despite amiodarone/beta blocker
• Superior to escalating medical therapy¹⁰

References

1)    Ortiz M, Martín A, Arribas F, et al. Randomized comparison of intravenous procainamide vs. intravenous amiodarone for the acute treatment of tolerated wide QRS tachycardia: the PROCAMIO study. Eur Heart J. 2016 Jun 28.

2)    Levine JH, Massumi A, Scheinman MM, et al. Intravenous amiodarone for recurrent sustained hypotensive ventricular tachyarrhythmias. Intravenous Amiodarone Multicenter Trial Group. J Am Coll Cardiol 1996; 27:67.

3)    Scheinman MM, Levine JH, Cannom DS, et al. Dose-ranging study of intravenous amiodarone in patients with life-threatening ventricular tachyarrhythmias. The Intravenous Amiodarone Multicenter Investigators Group. Circulation 1995; 92:3264.

4)    Murata H, Miyauchi Y, Hayashi M, et al. Clinical and Electrocardiographic Characteristics of Electrical Storms Due to Monomorphic Ventricular Tachycardia Refractory to Intravenous Amiodarone. Circ J 2015; 79:2130.

5)    Long B, Koyfman A. Best Clinical Practice: Emergency Medicine Management of Stable Monomorphic Ventricular Tachycardia. J Emerg Med. 2016 Oct 14. pii: S0736-4679(16)30721-1.

6)    Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation 2006; 114:e385.

7)    Eifling M, Razavi M, Massumi A. The evaluation and management of electrical storm. Tex Heart Inst J 2011; 38:111.

8)    Authors/Task Force members, Windecker S, Kolh P, et al. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J 2014; 35:2541.

9)    Nayyar S, Ganesan AN, Brooks AG, et al. Venturing into ventricular arrhythmia storm: a systematic review and meta-analysis. Eur Heart J 2013; 34:560.

10)   Sapp JL, Wells GA, Parkash R, et al. Ventricular Tachycardia Ablation versus Escalation of Antiarrhythmic Drugs. Circulation. N Engl J Med. 2016 Jul 14;375(2):111-21.