A method of determining at least one cardiovascular magnitude of a mammal, comprising a vessel (2), the method comprising: determining at least one impedance parameter in at least one set of electrodes (12, 13) using oscillating electrical signals that they contain a multitude of frequencies in a range from 100 Hz to 10 MHz or higher, in which the electrode set is within a selected distance with respect to a measuring site (1) of the vessel (2); estimating or determining an average diameter of the vessel (2) at a measurement site (1) based on said at least one impedance parameter determined on said at least one set of electrodes (12, 13); determining a dilation of the vessel (2) at the measurement site (1) based on said at least one impedance parameter determined on said at least one set of electrodes (12, 13); determining a pulse wave velocity and / or other magnitude related to the elasticity of the vessel (2) at the measurement site (1) based on said at least one impedance parameter determined on said at least one set of electrodes (12, 13); and calculate the at least one cardiovascular magnitude from the determined average diameter, the magnitude related to the elasticity and dilation of the vessel (2) at the measurement site (1).Un procedimiento de determinación de al menos una magnitud cardiovascular de un mamífero, que comprende un vaso (2), comprendiendo el procedimiento: determinar al menos un parámetro de impedancia en al menos un conjunto de electrodos (12, 13) usando señales eléctricas oscilantes que contienen una multitud de frecuencias en un intervalo desde 100 Hz a 10 MHz o más alta, en el que el conjunto de electrodos está dentro de una distancia seleccionada con respecto a un sitio de medición (1) del vaso (2); estimar o determinar un diámetro medio del vaso (2) en un sitio de medición (1) basándose en dicho al menos un parámetro de impedancia determinado en dicho al menos un conjunto de electrodos (12, 13); determinar una dilatación del vaso (2) en