In this paper, we present a proof of concept study which demonstrates for the first time the possibility to record magnetocardiography (MCG) signals with 4 He vector optically-pumped magnetometers (OPM) operated in a gradiometer mode. Resulting from a compromise between sensitivity, size and operability in a clinical environment, the developed magnetometers are based on the parametric resonance of helium in zero magnetic field. Sensors are operated at room-temperature and provide a tri-axis

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... or measurement of the magnetic field. Measured sensitivity is around 210 fT/√Hz in the bandwidth [2 Hz; 300 Hz]. MCG signals from a phantom and two healthy subjects are successfully recorded. Human MCG data obtained with the OPMs are compared to reference electrocardiogram (ECG) recordings: similar heart rates, shapes of the main patterns of the cardiac cycle (P/T waves, QRS complex) and QRS widths are obtained with both techniques.