[Severe ventricular arrhythmia secondary to indapamide-induced hypopotassemia]. / Aritmie ventricolari gravi secondarie a ipopotassiemia indotta dall'indapamide.

We report on two patients, treated with indapamide for mild hypertension, who developed life-threatening ventricular arrhythmias. The former showed severe hypokalemia, QT interval prolongation and "torsade de pointes": the latter, who suffered from ischemic heart disease, had slightly decreased serum potassium and ventricular fibrillation. In both cases no other cause accounting for hypokalemia and ventricular arrhythmia was found. Therefore we stress that serum potassium and ECG must be carefully monitored during indapamide therapy, mainly in patients with cardiac disease.

[Acute hybrid leukemia. Review of the literature and presentation of a case]. / La leucemia acuta ibrida. Rassegna della letteratura e illustrazione di un caso.

In the last years, the development of immunophenotypic and molecular analyses allowed to recognize several cases of hybrid acute leukemia (AL), whose blast cell display both lymphoid and myeloid features. Hybrid, or mixed-lineage, AL seems to have distinct clinical manifestations and hematological findings, and is mainly characterized by resistance to chemotherapy and poor prognosis. We report on a patient with AL, which showed a very rapid switch from the lymphoblastic phenotype exhibited at presentation to a myelomonoblastic one, appeared at first relapse, and lastly progressed to an undifferentiated leukemia in the terminal phase. Together with this morphologic and cytochemical evolution, leukemic cells expressed, besides the primary early-B antigens, new immunological markers related to T-lymphocytic and myeloid lineages. Based on this observation and current understanding of the ontogenesis of hematologic malignancies, we discuss biological mechanisms which are likely to underlie hybrid leukemia.