Spectral coherence between blood pressure and inter-beat intervals in hypertension.

Continuous registration of blood pressure (BP) was obtained in 31 normotensives and 76 hypertensives (divided into 3 stages of hypertension) by a method where the blood pressure in a human finger was measured non-invasively in a beat-by-beat fully calibrated manner. From this signal, the power density spectra of inter-beat intervals (IBI), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were derived. Total spectral power (TP) and low/high spectral frequency ratios of all spectra were calculated.

Relationship between heart rate variability and hypercholesterolaemia.

A statistically significant correlation between chronic (tonic) distress (expressed by long-term depression of heart rate variability-HRV) and the increase of the serum lipid level was found in the experimental group (39 clinically healthy subjects with hypercholesterolaemia; 16 women and 23 men; mean age 42.4 +/- 2.45 years).