1. Set of medical instruments for introduction through a hole in the target Thoracic atrium, comprising: a piercing tool, the size and design of which provide input to generate a target space in the atrium and in the corresponding portion of the pericardium, an elongated conductor having a central passage and adapted for movement through said place of entry and location over said piercing tool, said wire includes a distal end having a predetermined intracardiac length, a buffer disposed on said conductor and separating said distal end from the remainder of said conductor, said buffer for a restriction of said distal end through entry in the target atrium closing unit configured to transfer to the operating position to close said entrance into the desired atrium after removal of the atria of said conductor, wherein the dimensions and shape of said conductor and the central channel allow insertion and passage through them of tools for performing predetermined manipulations on the heart in the specified target predserdii.2. Set according to Claim. 1, wherein said buffer is configured to be provided opposite the outer part of the pericardium, a corresponding said point vhoda.3. The kit of claim. 2, where said buffer is at said conductor at a location at least partially to set this predetermined intracardiac dlinu.4. Set according to Claim. 1 further comprising a valve assembly,
