Anh DJ et al. (2006) Early human experience with use of a deflectable fiberoptic endocardial visualization catheter to facilitate coronary sinus cannulation. Heart Rhythm 3: 875–878

The success rate of cardiac resynchronization therapy (CRT) implantation, according to a recent study, could be improved by the use of an endocardial visualization catheter (EVC), which allows direct, real-time visualization of intracardiac structure.

Despite improvements in the techniques used, a significant number of CRT implantations fail, mainly because of the presence of complex anatomy that limits the ability to cannulate the coronary sinus (CS). In this study, 58 consecutive patients (mean age 72 ± 12 years; ejection fraction 26.2 ± 7.0%; NYHA class 2.9) requiring CRT implantation for a range of standard indications were imaged during the procedure using a steerable fiberoptic EVC. Visualization of the CS ostium was successful in all cases and the CS was cannulated in 57 (98.3%) patients. The mean time from EVC insertion to CS visualization was 6 ± 5 min, and the mean total time to CS access was 8 ± 6 min. Left ventricle implantation was accomplished in 55/58 (94.8%) patients, including 3 patients who had a previous history of failed left ventricular lead implantation. The three unsuccessful implantations in this study were caused by dissection of the CS during lead delivery in one patient, prevention of lead sheath placement because of tortuous angulations in a second, and the presence of a valve in the third.

The authors suggest that fiberoptic imaging using this technique can aid CS access and left ventricular lead placement by allowing visualization of right atrial anatomy during CRT implantation.