Intracardiac electrocardiography during permanent pacemaker implantation: predictors of cardiac perforation

Biventricular perforation by a temporary pacing electrode: recognition from the lateral chest radiograph

A temporary pacing electrode was inserted in a patient with severe calcific aortic stenosis complicated by complete atrioventricular block. Despite normal pacing and sensing function, a diagnosis of myocardial perforation was made on the basis of a lateral chest radiograph. Neither the surface electrocardiogram nor the frontal chest radiograph suggested evidence of myocardial perforation, and echocardiographic diagnosis was limited by poor echogenicity of the patient. Biventricular perforation with pericardial effusion were documented at operation.

Pacemaker electrode perforation of the myocardium: an unusual etiology for recurrent abdominal pain

A 79-year-old man with a permanent pacemaker presented on five separate occasions to the emergency department with recurrent episodes of crampy abdominal pain. Extensive radiographic studies and repetitive labwork were nondiagnostic. Shortly after hospital admission on the fifth visit he experienced cardiac arrest and was successfully resuscitated. Poor pacemaker capture and paced clonic contractions of the diaphragm and abdominal wall were noted, suggesting myocardial perforation by the pacemaker electrode. A new lead and pulse generator were implanted and the patient was discharged without further abdominal discomfort. Implications of pacemaker electrode perforation of the myocardium are discussed.

Real-time, two-dimensional echocardiographic features of pacemaker perforation

Five patients (four adults and one child) with clinically suspected myocardial perforation by temporary transvenous pacemakers were studied by real-time, two-dimensional echocardiography. In three patients, the catheters were visualized passing through the right ventricular apical wall with the tip located outside the cardiac border. In one patient the catheter perforated the atrioventricular septum and entered the left ventricle with the tip lodged against the posterior wall. In another patient, the catheter had partially penetrated the ventricular septum near the apex. Pericardial effusion was observed in two patients, in one of whom it was localized to the site of perforation. No patient had evidence of cardiac tamponade. In four patients, the catheters were withdrawn under echocardiographic visualization and the catheter tips could be seen moving from the abnormal locations back into the right-heart chambers. Perforation was verified at autopsy in two patients, including one in whom the catheter was not withdrawn. Real-time, two-dimensional echocardiography appears to be valuable in the diagnosis of pacemaker perforation.

Clinical experience with a programmable pacemaker

As part of a study to evaluate a new programmable pacemaker, 15 patients received lithium-powered R-wave inhibited, unipolar pulse-generators (CPI Model 0505). Five were initial implants (Group I) and 10 were pulse generator replacements (Group II). The follow-up period ranged from 1 to 18 months (mean 11 months). There were 5 deaths unrelated to the pacemaker. Three instances of pacemaker failure were identified and were characterized by a sudden loss of pacemaker output. THe malfunction, traced to a 10 kHz timing crystal, has been corrected in subsequently manufactured pulse-generators. In 11 patients, the pacemakers were programmed at a pulse width which was twice the threshold determined at 3 months. Four were programmed at 0.1 ms, three at 0.2 ms and four at 0.4 ms. Although no complications were seen in patients programmed at 0.1 ms pulse width, it might be advisable to leave pacemakers at 0.2 ms or greater for chronic pacing in patients with a pulse width threshold at 0.05 mg.