A rare, acute myeloid leukemia characterized by no significant myeloid maturation and more than 90% blast cells in the non-erythroid population. Various degrees of anemia, thrombocytopenia, or pancytopenia are present. Frequent clinical manifestations include fatigue, fever, bleeding disorders, and organomegaly, especially hepatosplenomegaly.

Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both.