DIFFERENTIAL-DIAGNOSIS OF TACHYCARDIAS WI TH A WIDENED QRS COMPLEX

The differential diagnosis of tachycardias with a widened QRS complex is a frequent problem that cardiologists and emergency room physicians must face. Ventricular tachycardias, supraventrical tachycardias with aberration of ventricular conduction and supraventricular tachycardia s conducted by accessory routes (pre-exited or antidromic) are the thr ee mechanisms that cause tachycardias with a reviewed QRS complex, who se clinical significance and treatments are different. Recently, intra cardiac electrophysiological studies allowed the identification of eff icient electrocardiographic criteria to distinguish each of these mech anisms. Several reports have indicated these criteria based on the car eful analysis of the surface electrocardiogram.