Implantable cardioverter-defibrillator: beyond efficacy.

OBJECTIVES: The introduction of the implantable cardioverter-defibrillator was a very important advance in the treatment of malignant ventricular arrhythmias. However, its use is associated with some possible adverse events, which should be taken into consideration when a patient is proposed for implantation. These complications may occur early after implantation and be associated with the procedure itself, or they may be late complications, usually associated with the device or the arrhythmia. It was our objective to assess the incidence of these complications in our population of patients. POPULATION AND METHODS: We describe the complications found in 98 patients (55.9 +/- 13.9 years, 89% male) with an implantable cardioverter-defibrillator and compare our results with the incidence of complications described by other authors. RESULTS: We found complications associated with the presence of the implantable cardioverter-defibrillator in 32% of patients. The most frequent complication was inappropriate shocks in 13%. The presence of infection was detected in 4%, lead insulation faults in 5%, need for lead extraction in 2%, repositioning in 1% and re-establishment of the connection with the generator in 2%. In 5% of patients, there was inefficacy of the device, 3% due to non-detected ventricular tachycardias (slow tachycardias) and 2% due to electrical storms. There was syncope in 2% of patients. The total mortality in a 2.9 +/- 1.9 year follow-up was 13% (sudden death in 3%). CONCLUSIONS: Major complications associated with implantable cardioverter-defibrillators were in our experience relatively rare, our results agreeing with those of other centers.

[Constrictive pericarditis: an early diagnosis?]. / Pericardite constritiva: um diagnóstico precoce?

The authors report a case study of a 73-year-old male, with signs of right-sided heart failure with 6 months of evolution. It was constrictive pericarditis, without radiologic, echocardiographic and magnetic resonance imaging manifestations, diagnosed on the basis of the clinical situation and hemodynamic evaluation during cardiac catheterization. The authors suggest that the lack of imagiologic manifestations might have been the result of an early diagnosis, before the development of the classic picture. Pericardiectomy, performed with success, was followed by resolution of the heart failure. It was not possible, histologically, to draw conclusions about the etiology. The development of mitral regurgitation after pericardiectomy has enriched this case with an unusual, but previously described, complication of this type of surgery.

[Acute megaloblastic anemia caused by inhalation of nitrous oxide in a patient with multiple autoimmune pathology]. / Anemia megaloblástica aguda por inalação de óxido nitroso em doente com patologia autoimune múltipla.

Although megaloblastic anemias are generally regarded as chronic conditions of insidious appearance, a megaloblastic state can arise over the course of only a few days due to acute folate or vitamin B12 deficiency. One of the most common causes, though seldom reported, is the nitrous oxide (N02) action in tissue. In fact N02, a volatile substance commonly used in anaesthesia, destroys methylcobalamin, leading to the rapid development of a megaloblastic haematopoiesis. This phenomenon may occur in patients without previous vitamin B12 deficit, but is more frequent and severe when there is a pre-existent deficiency state. A case report is described of a patient with femoral fracture who developed acute anemia after surgery and a latent pernicious anemia was revealed upon investigation.