The underlying cause of<unk><unk>  tachycardia tends to be ventricular tachycardia (VT) in patients > 35 years of age (sensitivity of 92% and a positive predictive value of 85% for VT) and supraventricular tachycardia (SVT) with aberrancy in patients < 35 years of age (positive predictive value of approximately 70%).
Wide complex tachycardia epidemiology and demographics
Paroxysmal supraventricular tachycardia classification
Second degree AV block epidemiology and demographics
Pulseless ventricular tachycardia epidemiology and demographics
Third degree AV block classification
First degree AV block classification
Pulseless ventricular tachycardia pathophysiology
Atrial flutter pathophysiology