Formalization of medical guidelines by means of a general GLIF graphic model is demonstrated in the formalized 2003 European Guidelines on Cardiovascular Disease Prevention and 2003 ESH/ESC Hypertension Guidelines. It leads a user through the decision algorithm in diagnostics of several diseases, total cardiovascular risk estimation and appropriate treatment. Moreover, it can show both the basic information and the appropriate part of guidelines (GL) complete text concerning the selected GLIF model element. The formalization of GL can function as a feedback for authors to remove uncertainties and information inconsistencies in GL. Estimation of the total cardiovascular risk and selection of a drug class is easier compared to a time consuming manipulation with tables of paper guidelines. It offers to physicians a system for a decision support and it checks their decision algorithms in comparison with those of GL. It could serve as a tool for an audit of physicians work by their professional society using the automatic system, preferably with a direct data access from a structured electronic health record in future. Computer GL presentation has the potential for an easier GL knowledge implementation than the classical paper GL form and thus to improve the primary care of cardiovascular diseases.