[Changes in Cardiac Output in the Initial Phases of Hypertension]

In what concerns to the early phases of arterial hypertension, the difficulty of definition, the usually found hemodynamic changes, especially of cardiac output, and its changes during evolution to established hypertension, are referred. The role of genetic determinants of predisposition to hypertension and of strain situations as factors of precipitation, with acute rise of blood pressure and cardiac output, is emphasized. It is also referred the importance of the early detection of true hypertensives by studying their reaction to strain situations, being particularly promising the mental stress tests and the dynamic exercise tests.