C  2007, the Authors Journal compilation C  2007, Blackwell Publishing, Inc. DOI: 10.1111/j.1540-8183.2007.00285.x Initial Experience with Alcohol Septal Ablation Using a Novel Magnetic Navigation System JOHN M. BUERGLER, M.D., F.A.C.C., 1 SHAHED ALAM, WILLIAM SPENCER, M.D., F.A.A.C., 2 NEAL S. KLEIMAN, M.D., F.A.C.C., 1 YELENA MELENDEZ, 1 JENNIFER FRANKLIN, R.N., 1 and SHERIF F. NAGUEH, M.D., F.A.C.C. 1 From the 1 Methodist DeBakey Heart Center, The Methodist Hospital, Houston, TX; 2 Division of Cardiology, Medical University of South Carolina, Charleston, SC Objectives: We compared the use of magnetically assisted intervention (MAI) with conventional guidewire tech- niques to perform alcohol septal ablation (ASA) in patients with hypertrophic obstructive cardiomyopathy (HOCM). Background: Treatment of symptomatic patients with HOCM using ASA has been established as an effective therapy. However, in many cases cannulaton of the septal artery can be technically challenging. Recently, a magnetically directed guidewire system has been developed to assist in navigation in difficult percutaneous interventions. By directing the guidewire to the septal branch, this system has potential to shorten the procedure time and increase success and safety of ASA in patients with HOCM. Methods: From October 2004 through October 2006, 44 consecutive patients underwent ASA using MAI with the Niobe  R system (Stereotaxis, Inc., St. Louis, MO). We compared these patients to 29 age- and gradient-matched cases using conventional techniques performed by an operator with >100 prior cases. Results: All procedures were successful. Both the MAI and conventional groups had improved symptoms, exercise times, and reduced gradients compared with baseline. One dissection occurred in the conventional group. Al- though there were no aggregate differences in acute or 3-month clinical outcomes, the time required for guidewire cannulation of the septal branch decreased progressively with increasing experience (third tertile vs first tertile (3 [1.25–4.75 vs 10.5 [6–17] minutes, P = 0.004) compared with the conventional group (6 [2–10.25] minutes, P = 0.075 vs third tertile), suggesting a learning curve for MAI. Conclusions: MAI has the potential to improve wiring time and outcomes of HOCM patients undergoing ASA. (J Interven Cardiol 2007;20:559–563) Introduction Treatment of symptomatic patients with hyper- trophic obstructive cardiomyopathy (HOCM) using al- cohol septal ablation (ASA) to reduce the mass of the ventricular septum has been established as an effec- tive therapy to reduce the outflow tract gradient and improve symptoms of dyspnea. 1–9 The success rate is Address for reprints: John M. Buergler, M.D., Department of Car- diology, 6550 Fannin, Suite 1901, Houston, TX 77030. Fax: (713) 790-6334; e-mail: jbuergler@tmh.tmc.edu Neal Kleiman has been a consultant to Stereotaxis, Inc. comparable to that of surgical myectomy. 10–14 The con- ventional approach to this procedure involves placing a small balloon into the target septal perforator artery and injecting absolute ethanol through its central lumen, re- sulting in a localized septal infarction with subsequent akinesis and thinning of the affected tissue. 10, 15,16 However, it is often difficult to cannulate the target septal artery due to its small diameter and/or angu- lation at its origin from the left anterior descending artery (LAD). 17,18 In these cases, the procedure cannot be performed or must be carried out at the expense of an excessively long procedure time. In addition, there may be a higher risk for arterial dissection related to repeated manipulation of the guidewire. Recently, a Vol. 20, No. 6, 2007 Journal of Interventional Cardiology 559