An<unk>  is a disorder of the heart rate, pulse, or heart rhythm, such as beating too fast (tachycardia), too slow (bradycardia), or irregularly.
Cardiac arrhythmia
Atrial infarction
Sinus arrhythmia
Atrial fibrillation
Pacemaker mediated tachycardia
Supraventricular tachycardia
Ventricular tachycardia
Torsades de pointes