MAPPING OF THE CORONARY SINUS AND GREAT CARDIAC VEIN USING A 2-FRENCHELECTRODE CATHETER AND A RIGHT FEMORAL APPROACH

Coronary Sinus Mapping. Introduction: Local electrograms recorded from the coronary sinus and great cardiac vein provide important informati on for the diagnosis of various arrhythmias and identification of targ et sites for ablation of left-sided accessory pathways, One limitation of present techniques is the inability, in many cases, to probe the g reat cardiac vein at the anterior mitral annulus. We tested the feasib ility of a new technique for catheterization of the coronary sinus and great cardiac vein by means of a small-diameter electrode catheter ad vanced via a right femoral approach through an angiography catheter. M ethods and Results: Of 22 patients (12 men and 10 women; ages 44.5 +/- 13.4 years) undergoing radiofrequency ablation of a supraventricular tachycardia, cannulation of the coronary sinus orifice using a 6-Frenc h 1L or 2L Amplatz catheter was achieved in 20 patients (91%) within 0 .9 +/- 0.6 minutes; after cannulation, a 2-French octapolar electrode catheter with a soft radiopaque tip and a 3-mm interelectrode distance could be advanced in all 20 patients through the guiding catheter to the great cardiac vein in the anterior region of the AV sulcus within 0.8 +/- 0.7 minutes, Atrial and ventricular local potentials were reco rded all along the mitral annulus during sinus rhythm, atrial and vent ricular pacing, or supraventricular tachycardia. Variation of local po tential amplitude never exceeded 20% of the mean and presented similar stability at all annular regions. The arrhythmogenic substrate was id entified in all patients. Of 18 patients with 21 left-sided accessory pathways, an accessory pathway potential could be recorded at the abla tion site by one or more adjacent epicardial electrode pairs in 10 pat hways. No procedure-related complications were observed. Conclusions: The technique introduced in this study proved feasible in 91% of patie nts. Its main advantages are the simplicity and rapidity of coronary s inus cannulation and the ability to advance the electrode catheter to the anterior cardiac vein. In addition, closely spaced bipolar electro grams resulted in enhanced atrial, ventricular, and accessory pathway potential resolution.