Perfuração tardia do miocárdio por cateter de pacemaker em doente assintomática

A 74-year-old woman had undergone implantation of a permanent pacemaker (VDD) for grade 3 atrioventricular block two years previously, with no intervening complications. At a routine follow-up consultation, although she presented no symptoms, pacemaker dysfunction was detected (undersensing and failure to capture). A posteroanterior chest X-ray showed the pacemaker lead tip protruding outside the heart (Figure 1). Thoracic 16-slice multidetector computed tomography, with multiplanar and three-dimensional reconstructions, confirmed the position of the lead tip outside the heart, with an intrathoracic course towards the diaphragm (Figures 2--4). Perforation of the myocardium by a pacemaker lead is a major, albeit uncommon, complication of such devices, with an incidence of 0.3--1.2%. Perforations are classified as acute (5--7 days after device implantation), subacute (7--30 days) or late (more than 30 days). Most cases reported in the literature occurred in the first year. Most patients with myocardial perforation are symptomatic, with chest pain, dyspnea, hypotension or