Differential diagnosis of wide QRS tachycardia: A review

Abstract

Differential diagnosis of wide QRS tachycardia (WQRST) on the electrocardiogram remains a challenging exercise. Correct diagnosis is important for prescribing appropriate therapy and determining prognosis. Differential diagnosis of wide QRS tachycardia revolves around differentiation between supraventricular tachycardia with aberrant conduction and ventricular tachycardia. Observations such as clinical history, findings of physical examination during tachycardia, AV dissociation, QRS morphology in lead V1 and lead V6, precordial concordance, RS complexes in precordial leads, contralateral bundle branch block during wide QRS tachycardia, R wave morphologies in lead aVR, and ventricular initial/terminal velocity of conduction ratio can help arrive at the correct diagnosis with reasonable accuracy. The observations described here can help arrive at the correct diagnosis of WQRST with both reasonable accuracy and confidence.

Abstract

The diagnosis of wide QRS tachycardia can be challenging, but is essential for appropriate therapy. The differentiation is often between supraventricular tachycardia with aberrant conduction and ventricular tachycardia. A review of historical, clinical, electrocardiographic information during wide QRS tachycardia while keeping in mind the pitfalls and exceptions, may help arrive at the correct diagnosis with reasonable accuracy and confidence