부산대학교 도서관

Background: Electrograms with delayed isolated component (E-IDC) and conduction channels (CC) identified by voltage mapping are the substrate (SB) of post-MI sustained monomorphic ventricular tachycardias (SMVT). We hypothesized that substrate based VT ablation (SBVTA) during sinus rhythm is safe and effective. The purpose of this study was to determine the long-term efficacy and identify predictors of VT recurrence after SBVTA.Methods: We analyzed 59 post-MI patients (age 67±9, LVEF: 30±11%) who underwent SBVTA. Electroanatomic maps were obtained to identify the scar (≤1,5 mV) and dense scar (≤ 0,5 mV). The targets of SBVTA were all E-IDC and CC in the scar.Results: Endocardial mapping was performed during RV pacing in 90% of patients and in the remaining patients during sinus rhythm. Maps were created with a mean of 120 points. Scar and dense scar extension were 76±42 and 34±24 cm respectively. E-IDC were identified in 93% of the patients with an extension of 17±10 cm. Endocardial voltage mapping identified ≥1 CC in 73% of patients these CC were related to the clinical or induced VT in 81% of the patients. After endocardial maps were completed all E-IDC/CC were tagged and ablated. The ablation area was 14±10 cm 2, no major life-threatening complications/incessant VT were observed during and after the procedure. During a median follow-up of 35 months 57% of patients remained free of VT recurrences. Univariable analysis identified LVEF (32±11 vs. 25±8%, p: 0.01), VT cycle length (379±103 vs 320±54, p<0,01, inferior vs. anterior infarct location (20 vs. 48%, p<0.04) and scar extension (<0.5 mV, 25±16 vs. 46±28 cm, p<0.0004) as predictor of VT recurrence. Cox proportional hazards model identified VT cycle length (p<0.002) and scar extension (p<0.0008) as the only independent predictor of VT recurrence.Conclusion: In post-MI patients SBVTA is safe and effective. Scar extension and VT cycle length are valuable predictors of post-MI SMVT recurrence.