<prompt> All of the following features can differentiate between ventricular tachycardia and supraventricular tachycardia except:QRs 0.14 secondsVentricular rate 160minVariable first hea soundRelieved by carotid sinus massage  <response>: Answer is B Ventricular rate 160min In both ventricular and supraventricular tachycardia the ventricular rate is greater than 100min, therefore ventricular rate 160min cannot be used to differentiate between ventricular supraventricular tachycardia. Ventricular tachycardia Broad complex tachycardia Ventricular rate 100 bpm QRS duration 0.12 sec. .14 sec.- HarrisonQ Cannot be relieved by carotid sinus massage. Q Supraventricular tachycardia Narrow complex tachycardia Ventricular rates 100 bpm QRS duration 0.12 sec. Can be relieved by carotid sinus message Q 100 bpm QRS duration 0.12 sec. .14 sec.- HarrisonQ Cannot be relieved by carotid sinus massage. Q alignleft height74 width277 100 bpm QRS duration 0.12 sec. Can be relieved by carotid sinus message Q alignleft height74 width314 Other features can be used to distinguish ventricular and supraventricular tachycardia. Variable First hea sound is a features of ventricular tachycardia only. In ventricular tachycardia QRS duration is greater then 0.14 Sec, while in supra ventricular tachycardia it is less than 0.14 Sec. Supraventricular tachycardia can be relieved by carotid sinus massage while ventricular tachycardia cannot. 