We have developed a magnetometer based on magnetic resonance in cesium vapor optically pumped by resonant laser radiation, which has the sensitivity and bandwidth to record human magnetocardiograms. The device is operated as a first-order gradiometer in a weakly shielded environment and allows us to record 2-dimensional field maps by shifting the subject with respect to a single sensor and making time-sequential measurements. We discuss the magnetometer technique and its performance as well as obtained results, which include a comparison of MCG data recorded with our single channel optical magnetometer with SQUID measurements from a commercial multi-channel device as well as from SQUID reference data. The results obtained so far in the detection of cardiomagnetic signals using the optical magnetometer make us confident that the technique has a high potential to serve as an alternative to SQUID detection.