[Stroke in a chronic autochthonous chagasic patient from the Brazilian Amazon].

An episode of stroke in a chronic autochthonous chagasic patient from the Brazilian Amazon is reported. This is the first documented case of a predominantly thromboembolic form of chronic Chagasic cardiopathy in the region.

[Magnetic resonance imaging in a patient with pacemaker].

The patient is a 24-year-old female with a dual-chamber pacemaker, who had intracranial hypertension, progressive visual loss, and several inconclusive cranial tomographies. She underwent magnetic resonance imaging, even though that diagnostic method is absolutely contraindicated in patients with pacemakers.

Block of the mitral-pulmonary isthmus during ablation of a single left-sided accessory pathway causing different patterns of retrograde atrial activation.

The case of a 16-year-old patient with atrioventricular tachycardia caused by a single left anterolateral accessory pathway is reported. When the patient underwent radiofrequency ablation, a lesion on the mitral annulus lateral wall produced changes in the retrograde atrial activation pattern determined by that pathway; changes ranged from a delay in depolarization of the annulus posterior portions to full left atrium counterclockwise activation. Such phenomena were probably caused by a block in the isthmus between the annulus and the lower left pulmonary vein ostium.