Abstract: A heart monitoring system for assessing a patient's cardiac condition. Bioimpedance components induce an electric current through the thorax of a patient's body and a first signal representing amplitude of transthoracic impedance as a function of time is obtained. Electrocardiograph components obtain an electrocardiograph signal from the patient simultaneously with the first signal. First processing circuitry is connected to the bioimpedance components for processing the first signal and producing therefrom a second signal representing cardiovascular hemodynamic changes as a function of time. Second processing circuitry is connected to the electrocardiograph components for measuring changes in the electrocardiograph signal. An analyzer is connected to the first and second processing circuits for producing an output indicating changes in a portion of the second signal over a period of time relative to changes in the electrocardiograph signal over the same period of time.