Method for the non-invasive determination of the load-independent contractility (Ees) of at least one cardiac ventricle of a person to be examined, comprising the following steps: la) determining the time course of the blood pressure during isovolumetric contraction and isovolumetric relaxation for at least one heart ventricle over at least one period of a heartbeat of a person, wherein a pressure curve is generated by measurement of the pressure course over one period of a heartbeat. Ib) Determining the velocity (v) of the regurgitant flow across the tricuspid valve by Doppler-flow-rate measurement from at least one pressure curve from step Ia). Ic) calculating the maximum right ventricular pressure (Pmax) from the velocity (v) of regurgitant flow from step Ib) ld) calibrating at least one pressure curve from step Ia) using the IVR and IVK times from step Ia) and the maximum right ventricular pressure (Pmax) of the subject under examination to obtain a calibrated pressure curve for this subject. Ie) Normalisation of at least one pressure curve from step Id) of the ventricle to be examined in order to obtain a calibrated normalised pressure curve. II. determination of the end-systolic pressure (Pes) from the calibrated normalised pressure curve from step Ie). III. determining the time course of the blood volume during isovolumetric contraction and isovolumetric relaxation for at least one heart ventricle over at least one period of a heartbeat of a person, wherein a volume curve is generated per measurement of the volume course over one period of a heartbeat. IV. Determining the end-systolic volume (Ves) from at least one of the volume curves from step III. V. Determine the intercept from the end-systolic volume (Ves) from step IV. VI. determining the load-independent contractility (Ees) of the cardiac ventricle of a person to be examined as the slope of the end-systolic pressure (Pes) from step II, the end-systolic volume (Ves) from step IV and the intercept from step V, wherein the load-independent contractility is the slope of the volume curve between the intercept and the end-systolic pressure (Pes) and thus Ees= Pes / (Ves-V0) applies. la) determining the time course of the blood pressure during isovolumetric contraction and isovolumetric relaxation for at least one heart ventricle over at least one period of a heartbeat of a person, wherein a pressure curve is generated by measurement of the pressure course over one period of a heartbeat. Ib) Determining the velocity (v) of the regurgitant flow across the tricuspid valve by Doppler-flow-rate measurement from at least one pressure curve from step Ia). Ic) calculating the maximum right ventricular pressure (Pmax) from the velocity (v) of regurgitant flow from step Ib) ld) calibrating at least one pressure curve from step Ia) using the IVR and IVK times from step Ia) and the maximum right ventricular pressure (Pmax) of the subject under examination to obtain a calibrated pressure curve for this subject. Ie) Normalisation of at least one pressure curve from step Id) of the ventricle to be examined in order to obtain a calibrated normalised pressure curve. II. determination of the end-systolic pressure (Pes) from the calibrated normalised pressure curve from step Ie). III. determining the time course of the blood volume during isovolumetric contraction and isovolumetric relaxation for at least one heart ventricle over at least one period of a heartbeat of a person, wherein a volume curve is generated per measurement of the volume course over one period of a heartbeat. IV. Determining the end-systolic volume (Ves) from at least one of the volume curves from step III. V. Determine the intercept from the end-systolic volume (Ves) from step IV. VI. determining the load-independent contractility (Ees) of the cardiac ventricle of a person to be examined as the slope of the end-systolic pressure (Pes) from step II, the end-systolic volume (Ves) from step IV and the intercept from step V, wherein the load-independent contractility is the slope of the volume curve between the intercept and the end-systolic pressure (Pes) and thus Ees= Pes / (Ves-V0) applies. II. determination of the end-systolic pressure (Pes) from the calibrated normalised pressure curve from step Ie). III. determining the time course of the blood volume during isovolumetric contraction and isovolumetric relaxation for at least one heart ventricle over at least one period of a heartbeat of a person, wherein a volume curve is generated per measurement of the volume course over one period of a heartbeat. IV. Determining the end-systolic volume (Ves) from at least one of the volume curves from step III. V. Determine the intercept from the end-systolic volume (Ves) from step IV. VI. determining the load-independent contractility (Ees) of the cardiac ventricle of a person to be examined as the slope of the end-systolic pressure (Pes) from step II, the end-systolic volume (Ves) from step IV and the intercept from step V, wherein the load-independent contractility is the slope of the volume curve between the intercept and the end-systolic pressure (Pes) and thus Ees= Pes / (Ves-V0) applies.