A causal approach to the calculation of coherence and transfer function between systolic pressure (SP) and RR interval variability was applied in eight patients and eight control subjects during prolonged tilt test for investigating the impairment of cardiovascular control related to neurally mediated syncope. The causal analysis showed a depressed baroreflex regulation in resting patients, with reduced gain and increased latency from SP to RR, and a drop of the baroreflex coupling immediately before syncope. These findings, which were not elicited by traditional cross-spectral analysis, strongly suggest the use of the causal approach for the study of syncope mechanisms. Â© 2006 IEEE.
|Numero di pagine||9|
|Rivista||IEEE Transactions on Biomedical Engineering|
|Stato di pubblicazione||Published - 2006|
All Science Journal Classification (ASJC) codes
- Biomedical Engineering