All of the following features can differentiate between ventricular tachycardia and supraventricular tachycardia except-

In SVT, AV-node drugs would work in normalizing the dysrhythmias. However, in VT, it won't work as it would worsen the condition of the patient. SVT relieved by carotid sinus massage VT has variying PR intervals so variying first hea sound In VT, Brugada sign, Josephson's sign, etc. are evident while SVT, narrow QRS complexes < 140 msec , a PR interval of less than 120 ms, etc. can be seen on the screen. Ref Harrison 20th edition pg 1556