A new approach for monitoring myocardium oedema is introduced. It utilizes electrical impedance spectroscopy (EIS) to characterize edema tissue. The system has been tested on an isolated pig heart to distinguish the edema from non-edema tissue by a decrease of impedance for edema. The impedance reduction for left ventricular was 10 Ω at 100 kHz. The algorithm used for the demodulation in the developed EIS system is based on Goertzel filter which is utilized to replace the traditional coherent demodulation technique. Multisine excitation with more than 1000 samples in the frequency range up to 1 MHz were used for the measurements.