BACKGROUND AND OBJECTIVE: This study examined the effect of transmyocardial laser revascularization (TMLR) on infarct size and global and regional left ventricular (LV) function. STUDY DESIGN/ MATERIALS AND METHODS: Acute ischemia was induced in 24 dogs by ligating the left anterior descending artery. TMLR was done through a left thoracotomy in 12 dogs. The 12 control dogs had ligation only. Global and regional LV function were measured before ligation, then at 6 hours or 3 months after ligation. We calculated the volumetric ratio of damaged myocardium to myocardium at risk (Vd/Vr). RESULTS: At 6 hours, global compensation despite regional dyskinesia was universal; Vd/Vr was the same in control and TMLR dogs. At 3 months, global function during stress was significantly higher in TMLR dogs than in control dogs (P < .05); regional contractions were synergic only in TMLR dogs; mean Vd/Vr was significantly lower in TMLR dogs. CONCLUSION: TMLR limits infarct expansion and improves long-term global and regional function after acute ischemia.
BACKGROUND AND OBJECTIVE: This study examined the effect of transmyocardial laser revascularization (TMLR) on infarct size and global and regional left ventricular (LV) function. STUDY DESIGN/ MATERIALS AND METHODS: Acute ischemia was induced in 24 dogs by ligating the left anterior descending artery. TMLR was done through a left thoracotomy in 12 dogs. The 12 control dogs had ligation only. Global and regional LV function were measured before ligation, then at 6 hours or 3 months after ligation. We calculated the volumetric ratio of damaged myocardium to myocardium at risk (Vd/Vr). RESULTS: At 6 hours, global compensation despite regional dyskinesia was universal; Vd/Vr was the same in control and TMLR dogs. At 3 months, global function during stress was significantly higher in TMLR dogs than in control dogs (P < .05); regional contractions were synergic only in TMLR dogs; mean Vd/Vr was significantly lower in TMLR dogs. CONCLUSION: TMLR limits infarct expansion and improves long-term global and regional function after acute ischemia.