ABSTRACT
Contributions of myocardial denervation Other investigators have implicated a therapeutic effect due to myocardial denervation after laserinduced injury. In a series of studies, Kwong and co-workers provided compelling physiologic and biochemical evidence of cardiac sympathetic denervation.32,33 Two weeks following transepicardial (Ho):YAG laser transmural channeling, cardiac afferent nerve function tested by the epicardial application of bradykinin was found blunted. Immunoblot analysis of tissue samples taken from laser-treated regions demonstrated a substantial reduction in tyrosine hydroxylase, an indirect measure of postganglionic sympathetic nerve density.32 In comparison to the transepicardial approach, trans-endocardial laser energy delivery induced only partial denervation.33 It is possible that the close anatomical proximity of the sympathetic nerve fibers to the epicardial surface render them less susceptible to non-transmural trans-endocardial laser channeling.
