Variability of Phase Shift Between Blood Pressure and Heart Rate Fluctuations - A Marker of Short-Term Circulation Control

0205681 - UPT-D 20030063 RIV US eng J - Journal Article
Halámek, Josef - Kára, T. - Jurák, Pavel - Souček, M. - Francis, D. - Davies, L. C. - Shen, W. K. - Coats, A. J. - Novák, M. - Nováková, Z. - Panovský, R. - Toman, J. - Šumbera, J. - Somers, V. K.
Variability of Phase Shift Between Blood Pressure and Heart Rate Fluctuations - A Marker of Short-Term Circulation Control.
Circulation. Roč. 108, č. 3 (2003), s. 292 - 297. ISSN 0009-7322. E-ISSN 1524-4539
R&D Projects: GA ČR GA102/00/1262; GA ČR GA102/02/1339
Institutional research plan: CEZ:AV0Z2065902
Keywords : baroreceptors * respiration * sudden death
Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery
Impact factor: 11.164, year: 2003

Background - We postulated that the variability of the phase shift between blood pressure and heart rate fluctuation near the frequency of 0.10 Hz might be useful in assessing autonomic circulatory control. Methods and Results - We tested this hypothesis in 4 groups of subjects: 28 young, healthy individuals; 13 elderly healthy individuals; patients with coronary heart disease; and 19 patients with a planned or implanted cardioverter-defibrillator (ICD recipients). Data from 5 minutes of free breathing and at 2 different, controlled breathing frequencies (0.10 and 0.33 Hz) were used. Clear differences (P<0.001) in variability of phase were evident between the ICD recipients and all other groups. Furthermore, at a breathing frequency of 0.10 Hz, differences in baroreflex sensitivity (P<0.01) also became evident, even though these differences were not apparent at the 0.33-Hz breathing frequency. Conclusions - The frequency of 0.01 Hz represents a useful and potentially important one for controlled breathing, at which differences in blood pressure - RR interactions become evident. These interactions, whether computed as a variability of phase to define stability of the blood pressure-heart rate interaction or defined as the baroreflex sensitivity to define the gain in heart rate response to blood pressure changes, are significantly different in patients at risk for sudden arrhythmic death. In young versus older healthy individuals, only baroreflex gain is different, with the variability of phase being similar in both groups. The measurements of short-term circulatory control might help in risk stratification for sudden cardiac death.
Permanent Link: http://hdl.handle.net/11104/0101294