In this article, we will discuss the Diagnosis of Ventricular Tachycardia. So, let’s get started.
The ECG helps in the diagnosis. Wide QRS complexes (>0.14 seconds), at a regular rate of >100 bpm with presence of AV dissociation (independent P-wave not related to wide QRS complexes), concordant pattern, superior QRS axis, capture beats and fusion complexes favour the diagnosis of VT. It may be monomorphic (all QRS complexes alike originating from a single focus) or polymorphic (QRS complexes are not alike suggests organ from multiple foci). Torsades de pointee is a form of polymorphic VT. It must be stressed here that in spite of all these criteria, the ECG diagnosis of VT is not only difficult but may be impossible to differentiate it from PSVT with aberrant conduction (another common cause of wide QRS tachycardia) because there is no single electrocardiographic sign which confirms the diagnosis of VT.
Following are the common causes of wide QRS tachycardia:
- Ventricular tachycardia
- Supraventricular tachycardia with aberrant intraventricular conduction (common)
- Supraventricular tachycardia with pre-existing bundle branch block (less common)
- Atrioventricular tachycardia (antidromic WPW conduction)