Right Ventricular Outflow Tract (RVOT) Tachycardia

Introduction

• Right ventricular outflow tract (RVOT) tachycardia is a form of monomorphic VT originating from the outflow tract of the right ventricle or occasionally from the tricuspid annulus.
• It is usually seen in patients without underlying structural heart disease, although may also occur in the context of arrhythmogenic right ventricular dysplasia (ARVD).

Diagnostic features

• Heart rate > 100 bpm.
• QRS duration > 120 ms.
• LBBB Morphology.
• Rightward / inferior axis (around +90 degree).
• Atrioventricular dissociation.

Other general features of VT, such as fusion and capture beats may also be present.

Causes

RVOT tachycardia is associated with two conditions:

Idiopathic VT

• Occurs in structurally normal hearts.
• Accounts for 10% of all VT.
• 70% of idiopathic VT will have a RVOT morphology.
• Underlying mechanism of c-AMP mediated triggered activity.
• May respond to adenosine.

Arrhythmogenic Right Ventricular Dysplasia

• An inherited myocardial disease associated with paroxysmal ventricular arrhythmias and sudden cardiac death.
• Characterized pathologically by fibro-fatty replacement of the right ventricular myocardium.

RVOT may be precipitated in both patient groups by catecholamine excess, stress, and physical activity.

Example ECGs

Example 1

RVOT tachycardia:

• Broad complex tachycardia.
• LBBB-like morphology.
• Inferior axis (+ 90 degrees).

Example 2

RVOT tachycardia:

• Broad complex tachycardia.
• LBBB-like morphology.
• Inferior axis (+ 90 degrees).

Video Lessons

• Professor Sanjay Sharma discusses Right Ventricular VT in ARVD.

Related Topics

• Ventricular tachycardia
• Arrhythmogenic Right Ventricular Dysplasia
• ECG Exigency 8 — “Sudden Syncope on the Soccer Field”

Further Reading

• ECG BASICS – Waves, Intervals, Segments and Clinical Interpretation
• ECG CLINICAL CASES – Your favourite ECG’s placed in clinical context with a challenging Q&A approach
• ECG and Cardiology Eponymous Syndromes – Cheats guide to eponymous emancipation
• ECG Reference Sites on the WEB – the best of the rest

Author Credits

• Words – John Larkin
• Pictures – Ed Burns
• Web Editing – Ed Burns

References

• Surawicz B, Knilans TK. Chou’s Electrocardiography in Clinical Practice. 6th Edition. Saunders Elsevier 2008.
• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.
• Lerman B, Stein KM, Markowitz SM, Mittal S, Slotwiner DJ. Right Ventricular Outflow Tract Tachycardia: An Update. Cardiac Electrophysiology Review. 2002;6, 1-2:68-71 PMID: 11984021