Macrophage activation syndrome in a patient with systemic lupus erythematosus undergoing cyclophosphamide treatment: a case report.

Macrophage activation syndrome (MAS) is a disorder related to hemophagocytic lymphohistiocytosis and is a life-threatening complication of rheumatic diseases. The diagnosis is challenging because MAS symptoms are quite similar to those of many active autoimmune diseases or severe sepsis. We describe the case of a female patient with systemic lupus erythematosus that presented with symptoms suggesting acute decompensation of autoimmune disease and sepsis. She was later diagnosed with MAS. Despite an aggressive immunosuppressive treatment, she developed a fatal outcome.

Cardiac arrest caused by undersensing of a temporary epicardial pacemaker.

The R-on-T phenomenon is a well-known entity that predisposes to dangerous arrhythmias. Typically, a premature ventricular complex occurring at the critical time during the T wave of the preceding beat precipitates ventricular tachycardia and fibrillation. This phenomenon can occur not only in asynchronous ventricular pacemakers, but also in synchronous pacemakers, if loss of sensing of the intrinsic rhythm becomes evident. A patient who was fitted with a temporary epicardial wire, following cardiac surgery and experienced repeated episodes of polymorphic ventricular tachycardia caused by the R-on-T phenomenon, is described.