399 The Long-Term Outcome of Visually Directed Subendocardial Resection in Patients Without Inducihie or Mappable Ventricular Tachycardia at the Time of Surgery SUNIL NATH, M.D., DAVID E. HAINES. M.D., IRVING L. KRON, M.D.,* and JOHN P. DiMARCO. M.D.. PH.D. From the Cardiovascular Division. Depanmenl of Medicine, and the ^Deparlnicnl of Surgery. University of Virginia Health Sciences Center. Charloltesville. Virginia Visually Directed Subendocardial Resection. iniroducHon: In prior studies. 20% to 40'^i- of putients under^oin^ subcndocardiiil resection (SKR) for ventricular tachycardia (VT) could not he mapped intraoperatively because the VT was either noninclucihie or nonniappahle fonowin}4 the ventriculotomy. The optimal sur}>icat approach to such patients i.s not known. Methods and Results: In this study, we retrospectively compared the long-term survival mid functional outcome of 29 patients with VT and prior myocardial infarction who were either noninducihie or nonmappahlc intraoperatively and underwent a visually directed extended SER. These results were then compared to 85 patients who had inducihie VT intraoperatively and underwent a map-guided sequential SKR. The two patient groups had different clinical characteristics. The visually directed cohort was more likely to he male, experienced fewer VT episodes hefore surgery, and underwent fewer antiarrhythniic drug trials prior to resection. In addition, the visually directed group had slower VT induced at a preoperative electrophysio- logic study and was less Hkely to present to the operating room in shock or incessant VT than the map-guided group. The postoperative VT clinical recurrenee or inducihility rate was 14% in hoth the visually directed and map-guided groups. The long-term actuarial survival at U 3, and 5 years was 93%, 86%. and 75%, respectively, in the visually directed group, compared to 77%, 58%, and 58%, respectively, in the map-guided group (P = 0.06). There were no docu- mented nonfatal recurrences of VT in either group. At 24 months following surgery, 77% of patients who had a visually directed SER were in New York Heart A.ssociation Functional Class I or II, compared to 46% ot patients who underwent a map-guided SER (P < 0.05). Conclusion: In patients with VT and prior myocardial infarction, the inahility to induce or map the VT in the operating room does not preclude a favorahle long-term outcome if a visu- ally directed extended SER technique is used. (J Cardiovasc Eleciruphysiol, Vol. 5, pp. 399-407, Mas ventricular tachycardia, aneurysm resection, cardiac mapping This siudy was presented in part at the 42nd Annual Scientific Sessions of the American College of Cardiology. March l^y.l. Aniiheini. Calirornia. Dr. Nath is a recipient of :i fellowship gram friiiTi ihe Nortli Amerit^an Stviciy tif Pacing and Rleclrophysiol- ogy. Address for correspondence: Sunil Nath. M.D.. Cardiovascular Division. MR4 Box 6()i2. University of Virginia Health Sciences Ccnier. Charlottcsville. VA 329OS. Fax: 804-982-3162. Manuscript received 19 January 1994; Accepted for publication 21 February 1994. Introduction The introduction of intraoperative map-directed subendtx:iirdial resection (SER) in 1979 by Joseph- son et al.'' revolutionized the surgical treulment of ventricular tachycardia (VT). However, as fur- ther experience with SER has been gained, a num- ber of limitations of the original hand-held elec- trode mapping lechnique have become apparent. Centers that use hiuid-held electrodes have reported