A method of vascularizing cardiac tissue using an instrument through the vascular system to an entry situs located at or adjacent the cardiac tissue is provided including providing a flowable agent comprising microspheres or microparticles having a particulate size range of 1 micron to 1 mm, introducing the agent through the instrument, imparting a particle moving force through the instrument that is generated externally to cause the microspheres or microparticles to pass directly through contiguous tissue to target cardiac tissue, the particle-moving force imparting a high pressure on the agent of several thousand psi, the microspheres or microparticles passing through the contiguous tissue without any mechanical means, whereupon the microspheres or microparticles directly enter the target cardiac tissue, forming channels in the wall of the myocardium at spaced locations and in communication with the interior of the heart, and introducing the flowable agent in the channels.