The number of diagnostic and therapeutic interventions performed outside of the operating room requiring anesthesia services has increased exponentially over the past 10 years. Anesthesiologists are engaged in doctor’s offices, ambulatory surgery centers, and endoscopy suites. Although cardiac anesthesiologists are most often involved with highly invasive heart surgery procedures, they too find an increasing part of their practice spent outside of the traditional heart surgery operating theater. Evermore complicated catheter-mediated procedures are completed in ever-sicker patients in the cardiac catheterization and electrophysiological laboratories. Increasingly, hybrid suites have been constructed to facilitate combined open and catheter-based surgeries. Common procedures include: diagnostic coronary angiography, coronary stenting, percutaneous closure of septal defects, electrophysiology studies, arrhythmia ablations, and implantations of pacemakers and cardioverter defibrillators. Also, as was previously discussed, catheter-based valve replacements and aortic aneurysm repairs are performed in hybrid procedural suites (see Chapters 6 and 9).
ELECTROPHYSIOLOGY AND OTHER CATHETER-BASED PROCEDURES OVERVIEW
Cardiac electrophysiology (EP) is the medical specialty devoted to the diagnosis and treatment of abnormal heart rhythms. It involves diagnostic EP testing, radiofrequency catheter ablation, and implantation of antiarrhythmic devices such as pacemakers and cardio-defibrillators.
Advanced medical research, new technology, an aging population, and the prolonged survival of very ill patients have added to the complexity of procedures performed and management of patients requiring EP therapies.1-5 The anesthesiologist is frequently consulted in both the cardiac catheterization and EP laboratories to help manage patients with severe coronary, valvular, and vascular diseases. Patients can experience hemodynamic perturbations secondary to arrhythmias, poor baseline ventricular function, or procedurally related iatrogenic myocardial perforation and tamponade. Anesthesiologists are called upon not only to maintain patient comfort during these procedures but also to be available to resuscitate the patient should hemodynamic or airway complications present.1 Procedures that might involve the anesthesia team include:
Coronary artery stenting: Coronary artery stents are used in the treatment of ST-elevation myocardial infarction, in-stent restenosis, stenting of saphenous vein grafts, and treatment of chronic coronary artery occlusions. Most of these procedures are performed under moderate sedation given by the nursing staff of the catheterization laboratory. Involvement of the anesthesia team typically is requested when the patient is hemodynamically unstable or there is a need for emergent airway management.
Percutaneous ventricular assist devices (VADs): Until recently, intra-aortic balloon counterpulsation with inotropic support was the main therapeutic option for supporting the failing ventricle. During the past few years, a number of percutaneous VAD designs have appeared that can be employed in the catheterization laboratory to provide emergent support for the failing heart (see Chapter 11).
Examples of percutaneous ventricular assist devices (PVADs) that can be placed in the cardiac catheterization laboratory include the TandemHeart (Cardiac Assist, Inc., Pittsburg, PA) and the Impella devices (Abiomed Inc., Danvers, MA). Anesthesia staff are often called upon to provide hemodynamic management when percutaneous VADs are employed. High-risk percutaneous coronary interventions are at times ...