THE DIFFERENTIAL-DIAGNOSIS ON THE ELECTROCARDIOGRAM BETWEEN VENTRICULAR-TACHYCARDIA AND PREEXCITED TACHYCARDIA

The 12-lead surface electrocardiogram is a simple and useful tool for the differential diagnosis of regular wide QRS complex tachycardia. Ho wever, criteria do not as yet exist to discriminate between ventricula r tachycardia and supraventricular tachycardia with anterograde conduc tion over an accessory pathway (preexcited tachycardia). Therefore, we designed a new stepwise approach with three criteria for the electroc ardiographic differential diagnosis between ventricular tachycardia an d preexcited tachycardia and prospectively studied 267 regular tachyca rdias with electrophysiologically proven mechanism and a wide QRS comp lex (greater-than-or-equal-to 0.12 s): 149 consecutive ventricular tac hycardias and 118 consecutive preexcited regular tachycardias. Underly ing heart disease was old myocardial infarction in 133 of 149 (89%) ve ntricular tachycardias. The patients presenting with preexcited tachyc ardia had no additional structural heart disease. Atrial fibrillation with preexcited QRS complex was not included. The criteria favoring ve ntricular tachycardia were: (1) presence of predominantly negative QRS complexes in the precordial leads V4 to V6, (2) presence of a QR comp lex in one or more of the precordial leads V2 to V6, and (3) AV relati on different from 1:1. (more QRS complexes than P waves). The final se nsitivity and specificity of these three consecutive steps to diagnose ventricular tachycardia were 0.75 and 1.00, respectively. This new st epwise approach is sensitive and highly specific for the differential diagnosis between ventricular tachycardia in coronary artery disease a nd preexcited regular tachycardia.