Reevaluation of Electrocardiographic and Bedside Criteria for Diagnosis of Ventricular Tachycardia

Abstract
Electrically induced ventricular and atrial tachycardias were observed in 12 cases, and ventriculoatrial (V-A) and atrioventricular (A-V) relationships were studied. It was noted that retrograde V-A conduction is a common phenomenon and that A-V dissociation is not a prerequisite for diagnosis of ventricular tachycardia. Conduction through the A-V node occurred readily in both antegrade and retrograde directions; and, all grades of block from first to complete and including the Wenckebach phenomenon were observed in both directions. The intensity of the first heart sound and the amplitude of the jugular a wave were governed directly by the temporal relationship between the P and the QRS regardless of whether conduction was antegrade, atrioventricular, or retrograde, ventriculoatrial. It is concluded that at present no electrocardiographic or bedside criteria are available for an unequivocal diagnosis of ventricular tachycardia and that further studies are needed.