Clinical and haemodynamic correlates of heart rate turbulence as a non-invasive index of baroreflex sensitivity in chronic heart failure
Résumé
Heart Rate Turbulence (HRT) describing the heart rate changes following a premature ventricular contraction, has been regarded as an indirect index of baroreflex function. However limited data are available on its relation to invasive assessment by phenylephrine injection (Phe_Slope). We therefore compared these methodologies in a series of heart failure (HF) patients in which both measures together with clinical and hemodynamic data were available. HRT parameters (turbulence onset, TO and turbulence slope, TS, were measured from 24-hour Holter recordings obtained within one week from baroreflex sensitivity assessment and right heart hemodynamic evaluation (Swan-Ganz catheter). HRT was computable in 135 out of 157 (86%) patients who had both phenylephrine test and hemodynamic evaluation. TO and TS significantly correlated with Phe_Slope (r=-0.39, p<.0001 and r=0.66, p<.0001 respectively). Age, baseline heart rate, left ventricular ejection fraction, pulmonary capillary pressure (PCP), cardiac index (CI) and sodium were significant and independent predictors of Phe_Slope, accounting for 51% of its variability. Similarly, age, baseline heart rate and PCP and NYHA class III-IV were independent predictors for TS and explained 48% of its variability while only CI and LVEF were found to be significantly related to TO and explained a very limited proportion (20%) of the variability. These data suggest that HRT may be regarded as a surrogate measure of baroreflex sensitivity in clinical and prognostic evaluation in heart failure patients.
Domaines
Médecine humaine et pathologie
Origine : Fichiers produits par l'(les) auteur(s)
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