ELECTROCARDIOGRAPHIC DIAGNOSIS OF VENTRIC ULAR-TACHYCARDIA

In monomorphic wide QRS complex tachycardia, it is important to differ entiate ventricular tachycardia from supraventricular tachycardia with aberration or preexcitation both from the prognostic and therapeutic view points. Atrioventricular dissociation with fusion complexes allow s diagnosis of ventricular tachycardia but the negative predictive val ue of these criteria is low. Extreme QRS axis deviation, concordant mo rphological criteria in leads V1-V2 and V6 and analysis of the RS comp lexes in the precordial leads, nearly always enable supraventricular t achycardia with aberration. The distinction with other causes of wide QRS complex tachycardias (supraventricular tachycardia with preexcitat ion or with non-systematised intraventricular conduction defects) is m uch more difficult in the absence of a reference recording and depends more on the clinical context than ECG analysis.