Fatal right-sided heart failure due to leukostasis in a patient with leukemic transformation of myelodysplastic syndrome.

We document leukostasis leading to acute fatal right-sided heart failure. In patients presenting with leukostasis and cardiopulmonary symptoms, clinicians should aim to assess for cardiac involvement, that is, by ECG and acute echocardiogram, since early recognition of right ventricular disease may provide an opportunity to treat this potentially reversible condition.