Correlations between the Poincaré plot and conventional heart rate variability parameters assessed during paced breathing

Aim: To analyze the correlation of the Poincaré plot descriptors of RR intervals with standard measures of heart rate variability (HRV) and spontaneous baroreflex sensitivity (BRS). A physiological model of changing respiratory rates from 6 to 15 breaths/min provided a wide range of RR intervals for analysis. Material and methods: Beat-to-beat...

Endothelial function and baroreflex sensitivity according to the oral glucose tolerance test in patients with coronary artery disease and normal fasting glucose levels

Endothelial dysfunction and reduced BRS (baroreflex sensitivity) may be present in patients with CAD (coronary artery disease). The normal fasting glucose level does not exclude abnormal glucose metabolism in patients with CAD. The aim of present study was to evaluate endothelial function and BRS according to glucose metabolism in patients with...

Sublingual nitroglycerin used in routine tilt testing provokes a cardiac output-mediated vasovagal response

Objectives We set out to determine the effect of sublingual nitroglycerin (NTG), as used during routine tilt testing in patients with unexplained syncope, on hemodynamic characteristics and baroreflex control of heart rate (HR) and systemic vascular resistance (SVR). Background Nitroglycerin is used in tilt testing to elicit a vasovagal response...

Time-domain cross-correlation baroreflex sensitivity: Performance on the EUROBAVAR data set

Objective: To test a new method (cross-correlation baroreflex sensitivity, xBRS) for the computation of time-domain baroreflex sensitivity on spontaneous blood pressure and heart interval variability using the EUROBAVAR data set. Methods: We applied xBRS to the 42 records in the EUROBAVAR data set, obtained from 21 patients in the lying and...

Should baroreflex sensitivity be corrected for heart rate?

Chemicals/CAS: phenylephrine, 532-38-7, 59-42-7, 61-76-7; Cardiotonic Agents; Phenylephrine, 59-42-7

Thoracic sympathectomy: Effects on hemodynamics and baroreflex control

Endoscopic thoracic sympathectomy at T2-T4 is an effective and safe treatment for primary axillary and palmar hyperhidrosis and facial blushing refractory to conventional treatment. T2 and T4 ganglia however are in the direct pathway of sympathetic innervation of the heart and part of the vasomotor nerves. In this study we investigate possible...

Why use Finapres or Portapres rather than intra-arterial or intermittent non-invasive techniques of blood pressure measurement?

In the clinic, blood pressure is measured almost exclusively using non- invasive intermittent techniques, of which the auscultatory (Riva- Rocci/Korotkoff, RRK) and the computerized oscillometric method are most often used. However, both methods only provide a momentary value. In addition, the accuracy is hampered by phenomena such as cuff...

The Valsalva manoeuvre as a cardiovascular reflex test in healthy children and teenagers

The objective of this study was to determine whether the Valsalva manoeuvre is applicable as a test for neurocardiovascular control in healthy children and teenagers. Sixty-eight 6- to 16-year-old children and teenagers performed two Valsalva manoeuvres in the sitting position. They were instructed to maintain airway pressure (strain) for 15 s...

Finapres tracking of systolic pressure and baroreflex sensitivity improved by waveform filtering

Objective. Arterial pressure waveforms distort between brachial and finger arteries, causing differences mainly in systolic pressure. Distortion, reportedly, can be removed by applying a waveform filter to the finger pressure. Design. We analysed the data from two studies that detected discrepancies in systolic tracking between Finapres and...