Relationships of the Cardiac Signal and Heat Acclimated State: Spectral Profiles from ECG Analysis

摘要

ECG signal has been analyzed to assess the state of heat acclimation in rats. Adult rats, were divided into control and aceleration groups. The ECG signals were obtained from the telemetry transmitters implanted into the rats. The power spectral density of unit time-differenced ECG series was computed. The spectral profiles for the accelerated rats show significantly smoother profiles following heat acclimation compared to the same for the control rats. The progression of acclimation also can be confirmed from the statistical comparison against the acclimated spectral pattern. The Mann-Whitney rank sum statistic (MWRS) between the average energy spectral profile and the spectral profile for individual days shows that subsequent to acclimation, the MWRS usually drops to low values (usually <1), whereas it remains >1 and usually >1.96 for the control group. The differential profiles derived by subtracting the bi-directionally low-pass filtered profile from the original spectral profile show distinctly reduced variations for the heat acclimated rats compared to the control rats.