Because no well-controlled study of inadvertent coronary air embolism has been done to truly quantify the incidence of this cardiac catheterization complication, we wanted to determine its incidence and severity in an active teaching medical center and assess approaches to treatment. We retrospectively reviewed 3,715 coronary angiogram and PTCA reports performed over 32 months. Further, we classified severity based on angiographic findings and symptoms as minimal, mild, moderate, and massive. Two independent angiographers reviewed 764 consecutive cines performed in the first 2 months of training of each new fellow and 740 cines performed in the last 2 months of training. We found that during the first 2 months of training the overall incidence for significant intracoronary air embolism was 0.19% (7 documented cases) compared with 0.2% (3 cases) for non-reported, minimal asymptomatic air embolism. The estimated incidence for total air emboli events was 0.27% (10/3,715). We did not find coronary air emboli in the 740 cines performed at the end of fellowship training. Additionally, the incidence of coronary air emboli during PTCA training was much higher compared with coronary angiography training (0.84 vs. 0.24%). Although there is no best technique to restore blood flow after blockage by air emboli, we suggest as options aspirating the air or forcefully injecting saline, with auxiliary supportive measures like 100% oxygen, IABP, CPR, and DC cardioversion.

On the basis of these observations, we believe that the Webster/Mansfield catheter can be reused an average of five times. It is strongly recommended that after each use catheters be carefully examined under appropriate magnification (x30) and that special attention be given to the ablation tip electrode. The catheters should also be tested for deflection and electrical integrity.

Ablation of arrhythmogenic cardiac tissues has emerged as one of the most important advances in cardiac electrophysiology. With the introduction of transcatheter ablation, the treatment of ventricular tachycardia, Wolff-Parkinson-White syndrome and other cardiac arrhythmias has progressed from an expensive and painful surgical therapy accompanied by a long recovery period to the less expensive, less traumatic transcatheter approach. The feasibility of cardiac ablation, along with the increasing number of physicians using the technique, requires understanding of the anatomic and electrophysiologic bases of transcatheter ablation as well as the different technologies, their limitations and complications. This report provides an overview of the physical, scientific and technical aspects of cardiac ablation performed with the methods currently available and a summary of the limitations of each method and expected future technologic developments in this growing field. Emphasis is placed on radiofrequency and direct current energies, the primary methods now used. Methods such as cryoablation and laser, and microwave and chemical ablation are discussed with less detail because the method of delivering energy for these ablative procedures has not been fully developed.