Ventricular tachycardia is defined as three or more ventricular complexes in succession at a rate greater than 100 bpm. Patients presenting with ventricular tachycardia often present with a regular heart rate between 100 and 250 bpm (HR below = 146 bpm), in which the QRS morphology is constant and abnormally wide (greater than 0.12 seconds). Frequently, these ECG's demonstrate AV dissociation in which the ventricular rate is greater than the atrial rate. P waves are frequently hidden within the broad ventricular complexes, although they can sometimes be identified as bumps or notches in the ventricular cycles. Although patients without heart disease may develop paroxysmal non-sustained ventricular tachycardia, chronic sustained VT is most commonly associated with coronary artery disease, dilated cardiomyopathy and prior myocardial infarction or severe heart disease.