Lawrence E. Widman

Infection of an Implantable Cardioverter Defibrillator: Management Without Removal of the Device in Selected Cases

A case is presented in which an implantable Cardioverter defibrillator (ICD) became infected in the abdominal wall pocket 5 weeks following implantation. There was no evidence clinically or by computed tomographic scan suggesting mediastinal extension of the infection. The infection was treated successfully by debriding the abdominaJ wall pocket followed by a combination of pocket irrigation with antibiotic solution, parenteraJ antibiotics, and long‐term oral antibiotics. This conservative therapy was and avoided removal of the device.

A semi-quantitative, three-dimensional model of cardiac electrophysiology

Catheter-mediated radiofrequency ablation is a medical procedure performed by highly trained and experienced cardiology sub-specialists. Even though these physicians are highly trained, the massive amount of data produced during these procedures creates a data overload problem that can impede the performance of even the best practitioners. Performance may be effected if the physician overlooks important signal features, misinterprets the signals, and/or misinterprets catheter locations in the heart, which may lead to increased procedure duration and/or applications of radiofrequency energy to the wrong part of the heart. To assist physicians performing catheter-mediated radiofrequency ablation procedures cope with the massive amount of data generated by the procedure, the authors began developing a computer-based system for analysing the signals generated by the procedure. As part of this effort, they have developed a semi-quantitative three-dimensional model of cardiac electrophysiology. This model has been implemented as part of the EINTHOVEN system, a computer-based system aimed interpreting the electrical signals from the heart. The authors incorporated the model into the EINTHOVEN system and developed and implemented new model-based algorithms for the system that together enable the system to interpret intracardiac electrograms in near real-time. The semi-quantitative three-dimensional model of cardiac electrophysiology and the model-based reasoning algorithms implemented to enable the EINTHOVEN system for analyzing intracardiac electrograms are presented.