Effects of mammography positioning on the autonomic nervous function

The physical and psychological burden on patients during mammography was analyzed using the autonomic function index in 34 adult females. The indices included heart rate (HR), high frequency (HF) of the R-R interval on an electrocardiogram, and the ratio of HF to LF (low frequency) (LF/HF). HR is an indicator of the degree of mental and physical activity, HF indicates the parasympathetic index and LF/HF indicates the sympathetic index. For the mediolateral oblique (MLO) view in mammography, autonomic function indices were measured before and during mammography. Statistical analysis was performed by the Mann-Whitney U test and the significance level was set at 5%. The autonomic function indices were compared before and during mammography and all showed no significant differences. The average value before imaging and the reference value at rest were compared. The results showed that HR increased 1.3-fold, HF increased 0.4-fold, and LF/HF increased 3.2-fold over reference values. Chronological changes during mammography showed that HF increased and LF/HF decreased from 120 seconds after the start of imaging. From these observations, it is evident that the state before mammography is not the same as the resting state and that the sympathetic index is dominant before imaging. They also suggest that some aspects of the psychological burden experienced during mammography are not due to the pain of breast compression alone.