Do alpha-index and phenylephrine test provide similar measurements of baroreflex sensitivity in cardiac patients with chronic heart failure?

R. Colombo, G. Mazzuero, P. Lanfranchi, G. Spinatonda, G. Minuco, P. Giannuzzi

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

To verify whether the phenylephrine test (PHE) and spectral analysis (alpha-index) provide similar measures of haroreflex sensitivity in patients with chronic heart failure due to left ventricular dysfunction, we evaluated by both methods a group of 40 pts during rest and controlled breathing (CB). R-R interval (RR), blood pressure (BP) and respiration were recorded in both conditions (600 heart beats), and bivariate spectral analysis was carried out. The alpha-index was measured when the magnitude squared coherence (MSC) between RR variability and systolic BP variability was > 0.5 in the low frequency (αLF) and high frequency (αHF) bands; the mean a was also computed. PHE followed immediately, with at least 3 injections during rest and one during CB. αLF could not be measured during both rest and CB in 40% of pts. The PHE slope could not be found in 7% of pts during rest and in 10% during CB. Regression analysis of the PHE slope vs αLF (r=0.61), α HF (r=0.63) and α(r=0.67) showed a weak correlation during rest. No correlation was found during CB.

Original languageEnglish
Title of host publicationComputers in Cardiology
Pages89-92
Number of pages4
Volume0
Edition0
Publication statusPublished - 1996

ASJC Scopus subject areas

  • Software
  • Cardiology and Cardiovascular Medicine

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