Electrocardiographic change	Criterion present	Criterion not present
1. RS complex absent from all precordial leads	VT present; stop and treat	Proceed to 2
2. R S complex is present, and the longest precordial RS interval is > 100 msec in one or more precordial leads	VT present; stop and treat	Proceed to 3
3. Atrioventricular dissociation is present	VT present; stop and treat	Proceed to 4
4. Morphologic criteria for VT* present in precordial leads V1 to V2 and V6	VT present; stop and treat	Supraventricular tachycardia with aberrant conduction is diagnosis made by exclusion