The goal of our search consists in analysing the metaphor in the speciality language which still constitute a reflexion theme not very well clarified. In this perspective, the analysis of the metaphor in the cardiology language represents a real ambitious adventure, as it is a will to demonstrate that it is not only a simple way to talk, but also a key element of our thought and world experience. One of the major point of this work is to bring a reflexion and a contribution to nature and to the various functions hold by the metaphor in the medical terminology. To do it, we have presented a possible data basis model which throw light on the elucidation of certain questions regarding the terminological metaphor. Thus, for us, there is no doubt that in the scientific activity, the metaphor is a need, a precious tool, but endowed with characteristical operating instructions. Yet, for a long time this vision of the metaphor was not in favour, as it contrasted with the Wusterian tradition which had considered the metaphor as a non rational entity aiming at vague representations said to be not only subjectives but also devoid of any scientific rigour, and carrier of ambiguity. Our position is different. The metaphor is a path often followed by scientists who can appreciate its ability to produce knowledge and to denominate. We have also seen that the terminological metaphor has an undeniable walk-on part in the specialized communication, a fact that had been refutated for a long time. The terminological metaphor in the cardiology field carries out five functions: cognitive, heuristic, denominative, metalinguistic, didactic. Finally we will end with the idea of the metaphor presenting itself as a linguistic key with cognitive conceptualization among sciences field. (Isabelle De Oliveira)