Electrocardiographic features include: *<unk>  rate: 100 to 250 BPM * Ventricular conduction can be variable * Irregular or irregularly irregular in the setting of variable AV block * Regular if 1 to 1, 2 to 1, or 4 to 1 AV block * P wave morphology * Unifocal, but similar in morphology to each other * Might be inverted * Differs from normal sinus P wave * May exhibit either long RP or short PR intervals * Rhythm may be paroxysmal or sustained * May demonstrate an increase in the rate at initiation (i.e., “warm up,” or “rev up”) * May demonstrate a decrease in the rate at termination (i.e., “cool down”)
Atrial tachycardia
Tachycardia
Sinus arrhythmia
AV nodal reentrant tachycardia  AV-nodal reentrant tachycardia  1
Junctional tachycardia
Ventricular tachycardia
Sinus tachycardia
Ectopic beat