Runs of Wide-Complex Tachycardia on Telemetry - Dr. Littmann

Differential Diagnosis

1. SVT with aberrancy (SVT with RBBB or SVT with LBBB)
2. Nonsustained VT
3. Artifact
4. Uncertain (“I don’t know”) – this is a better choice than incorrect guessing!

 
When the intrinsic rhythm is sinus:
I. What was the first beat of the tachycardia?

1. If the first early beat was a PAC (premature P wave in front of the QRS) -> SVT
2. If the first early beat was a PVC (no premature P wave in front of the QRS) -> VT

II. What is the P-QRS relationship?

1. A-V dissociation present -> VT
2. More QRS complexes than P waves -> VT

III. Fusion complexes present? -> VT

1. Combination QRS morphology (QRS wider than during sinus but narrower than the widest QRS)
2. P waves must be present in front of the combination morphology QRS complexes

 
When the intrinsic rhythm is atrial fibrillation:

1. If the WCT is regular -> VT

 
Artifact
Always consider artifact if:

1. It is uncertain which was the first or the last beat of the WCT
2. The rate of the tachycardia was excessive
3. The patient remained asymptomatic during a long run of a very fast tachycardia

Prove artifact by demonstrating that the

1. Intrinsic QRS complexes march through
2. “Notches” march through
3. Simultaneous hemodynamic tracing indicates regularity

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