Transmyocardial revascularization aggravates myocardial ischemia around the channels in the immediate phase

We examined whether transmyocardial revascularization (TMR) relieves myocar dial ischemia by increasing regional perfusion via the transmural channels in acute canine experiments. Regional blood flow during transient coronary ligation (2 min) was compared before and 30 min after TMR, and at the third transient ischemia the mid-left ventricle (LV) was cut and immediately fro zen along the short axis for the analysis of NADH fluorescence in the regio ns around the TMR channels. In low-resolution analysis (2-4 g tissue or 2-3 cm(2) area), regional perfusion was not significantly altered after TMR, a nd NADH fluorescence was observed throughout the ischemic region without si gnificant spatial variation. High-resolution analysis (2.8 mg, 1 mm x 1 mm) revealed that the flow after TMR was lower, and NADH fluorescence was high er in the regions close to the channels (1-2 mm) than in the regions 3-4 mm away from them. Creating TMR channels did not improve the regional perfusi on and rather aggravated the local ischemia in the vicinity of the channels in the immediate phase.