This post is an answer to the ECG Case 254
- Rate: 132 bpm
- Rhythm: Regular, evidence of possible AV dissociation
- Notching best seen in rhythm strip irregularly occurs at differing portions of QRS ( red circles in the rhythm strip below)
- Axis: Right / Inferior (105 deg)
- Intervals: QRS – Prolonged (100ms)
- Additional:
- Discordant ST / T-wave changes
- LBBB morphology
- General DDx include: Broad Complex Tachycardia
- Ventricular tachycardia
- SVT with aberrancy
- SVT with pre-existing block
- SVT with pre-excitation / WPW
- Paced rhythm
- Electrolyte abnormality / toxicological / environmental
Interpretation
The combination of LBBB morphology and 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. Following vagal maneuvers the patient’s subsequent ECG is below.
This ECG shows a combination of sinus rhythm and ventricular ectopics. Note the normal T wave morphology in the precordial leads, inferior axis and lack of epsilon wave in the sinus complexes. The ventricular ectopics share the same LBBB morphology and inferior / right axis seen in the first ECG and are occurring frequently.
The patient was given iv verapamil and returned to consistent sinus rhythm, long term management will be with plan ablation therapy. RVOT can also be seen in arrhythmogenic right ventricular dysplasia.
READ MORE: Never Mistake Ventricular Tachycardia for Supraventricular Tachycardia with Aberrant Conduction
SIMILAR CASE: ECG Case 102: Ventricular Tachycardia, probably Right Ventricular Outflow Tract Tachycardia (RVOT)
