Rat electrocardiogram during acute exposure to synchronized bursts of ultra-wideband pulses

Rats under ketamine anesthesia were exposed to bursts of ultra-wideband (UWB) electromagnetic pulses at two different times during the electrocardiogram (ECG) to investigate possible changes in the ECG immediately after start of exposure. Animals were exposed to UWB pulses in a giga transverse electromagnetic cell (GTEM) with the body axis parallel to the direction of UWB propagation (k-polarization) or the magnetic field vector (H-polarization) in separate experiments. In both experiments, UWB pulses at animal thorax had 106 kV/m peak amplitude, 0.78-0.79 ns duration, and 170-186 ps rise time (mean values) and were applied in 25-ms bursts at 1-kHz repetition frequency. The bursts were synchronized to the artifact-free ECG and occurred either during the R-wave or the T-wave of the ECG. Time intervals measured and analyzed in the ECG were PR, the time between start of P-wave and start of R-wave; RT, the time between start of R-wave and apex of the T-wave; and QT, the time between start of R-wave and end of T-wave. The time between successive R-waves, RR, was also determined. No change attributable to UWB exposure was seen in any of these intervals within 5 cardiac cycles of the start of exposure. We conclude that UWB pulses applied during the R-wave or the T-wave do not acutely change timing of events in the cardiac cycle of the anesthetized rat.