Absence of heart-rate effects in isolated frog heart irradiated with pulse modulated microwave energy.

Isolated frog hearts were irradiated with pulse modulated microwave energy synchronized with the ECG. No statistically significant or otherwise observable differences were found between the heart rate of irradiated groups and the nonirradiated control group. Experiments were performed to explore the possible effects of currents induced between the recording electrodes. Increases in heart rate occurred when applied current pulses between 20 and 30 mA were synchronized with the ECG during an interval from 200 msec to 300 msec after the peak of the P wave.