Paced respiration revealed a strong correlation between cardiac beat-to-beat interval and pulse transit time (r = +0.69, p < 0.01), with RR changes followed by PTT changes 3.17 beats later.
Observational (n=15)
What is the relationship between heart rate and pulse transit time during paced respiration in healthy subjects?
There is a strong, out-of-phase relationship between pulse transit time changes and RR interval changes during paced respiration.
Effect estimate: r = +0.69
p-value: p=< 0.01
Pulse transit time (PTT) is a simple, non-invasive measurement, defined as the time taken from a reference time for the pulse pressure wave to travel to the periphery. 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 cardiac beat-to-beat interval (RR) and PTT, using paced respiration to generate changes in both variables. We analysed PTT and RR interval from 15 normal healthy subjects during paced breathing, and the cross-correlation function between PTT and RR was used to quantify their relationship. Over the 15 subjects, the maximum change in PTT ranged from 7 to 23 ms with a mean +/- standard deviation of 14 +/- 5 ms, and that in RR interval from 86 to 443 ms (241 +/- 102 ms). Examining changes over time, the best correlation (r = +0.69, p < 0.01) was obtained when PTT was advanced relative to RR, with a change in RR followed by a corresponding change in PTT 3.17 +/- 0.76 beats later. We conclude that there is a strong relationship between PTT changes and RR interval changes, but these changes are not in phase.
Drinnan et al. (Thu,) conducted a observational in Healthy (n=15). Paced respiration was evaluated on Correlation between cardiac beat-to-beat interval (RR) and pulse transit time (PTT) (r = +0.69, p=< 0.01). Paced respiration revealed a strong correlation between cardiac beat-to-beat interval and pulse transit time (r = +0.69, p < 0.01), with RR changes followed by PTT changes 3.17 beats later.