Relation between heart rate variability and pulse transit time according to anesthetic concentration

The pulse transit time (PTT) can be measured between the ECG R peak and the linger pulse and this method is a simple, non-invasive measurement. PTT is influenced by heart rate, blood pressure changes and the compliance of the arteries, but few quantitative data are available describing the factors which influence PTT. The aim of this study was to investigate the relationship between the heart rate variability(HRV) and PTT under general anesthesia. We analyzed PTT and PSD of the HRV from 10 subjects during operation according to anesthetic concentration. Over the 10 subjects, the higher the anesthetic concentration, relation of PTT of LF was inverse proportion. But HF and LF/HF ratio had large SD, so the results not useful to know the relation between HRV and PTT. We conclude that there is a strong relationship between PTT changes and LF changes, but these changes are not in HF and LF/HF.