THE LONG-TERM OUTCOME OF VISUALLY DIRECTED SUBENDOCARDIAL RESECTION IN PATIENTS WITHOUT INDUCIBLE OR MAPPABLE VENTRICULAR-TACHYCARDIA AT THE TIME OF SURGERY

Introduction: In prior studies, 20% to 40% of patients undergoing subendocardial resection (SER) for ventricular tachycardia (VT) could not be mapped intraoperatively because the VT was either noninducible or nonmappable following the ventriculotomy. The optimal surgical approach to such patients is not known. Methods and Results: In this study, we retrospectively compared the long-term survival and functional outcome of 29 patients with VT and prior myocardial infarction who were either noninducible or nonmappable intraoperatively and underwent a visually directed extended SER. These results were then compared to 85 patients who had inducible VT intraoperatively and underwent a map-guided sequential SER. The two patient groups had different clinical characteristics. The visually directed cohort was more likely to be male, experienced fewer VT episodes before surgery, and underwent fewer antiarrhythmic drug trials prior to resection. In addition, the visually directed group had slower VT induced ata preoperative electrophysiologic study and was less likely to present to the operating room in shock or incessant VT than the map,guided group. The postoperative VT clinical recurrence or inducibility rate was 14% in both the;visually directed and map-guided groups. The long-term actuarial survival at 1, 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 documented 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 Association Functional Class I or II, compared to 46% of patients who underwent a map-guided SER (P<0.05). Conclusion: In patients with VT and prior myocardial infarction, the inability to induce or map the VT in the operating room does not preclude a favorable long-term outcome if a visually directed extended SER technique is used.