Impact of Nd : YAG laser radiation (λ = 1.44 mm) on myocardial tissue in the treatment of coronary heart disease by transmyocardial laser revascularisation

We have studied the impact of Nd : YAG laser radiation with a wavelength of λ = 1.44 μm on the myocardial tissue for the formation of channels in the treatment of coronary heart disease by transmyocardial laser revascularisation (TMLR). The mechanism of perforation of the myocardial tissue by a laser pulse is presented and an experimental setup for TMLR is developed. In experiments on biological objects, the optimal parameters of radiation energy and duration necessary for the formation of channels of a given size in a single laser pulse are determined. The exposure regime ensures the adequate character of myocardial tissue destruction, assessed by such criteria as the perforation force, exposure energy, size of the coagulation zone, and level of carbonisation.