ECG of the Week - 21st January 2019 - Interpretation

The following ECG is from a 34 year old female who presented with palpitations and dysponea.

Click to enlarge

Rate:

• 132 bpm

Rhythm:

• Regular
• AV dissociation

Axis:

• Inferior
• Near isoelectric lead I with positive lead aVF

Intervals:

• QRS - Prolonged

Additional:

• LBBB Morphology
• Nil capture beats
• Nil fusion beats

Interpretation:

• Wide complex tachycardia
• LBBB Morphology with inferior axis and features supportive of VT (AV dissociation)

What happened ?

The combination of LBBB morphology and inferior/right axis deviation is consistent with Right Ventricular Outflow Tract Tachycardia (RVOT). This is a type of monomorphic VT originating from the right outflow tract or tricuspid annulus it is commonly seen in structurally normal hearts and is usually haemodynamically well tolerated. RVOT can be terminated with vagal maneuvers, adenosine and is also sensitive to verapamil, this patient reverted following vagal manoeuvres. 

RVOT can also be seen in arrhythmogenic right ventricular dysplasia (ARVD).

There is a great and brief overview of idiopathic ventricular tachycardias from the E-Journal of the ESC Council for Cardiology Practice that I would recommend:

• Diez DP, Brugada J. How to recognise and manage idiopathic ventricular tachycardia.E-Journal of the ESC Council for Cardiology Practice. March 2010.

References / Further Reading

Life in the Fast Lane

• Right Ventricular Outflow Tract Tachycardia  

Textbook

• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.