Autonomic nervous system and microvascular alterations in normotensives with a family history of hypertension

Abstract

Autonomic nervous system and microvascular alterations at pre‐hypertensive stage of hypertension have still not been fully elucidated. We aimed at addressing central and local influences on microvascular reactivity at pre‐hypertensive stage of hypertension. To that end, we studied microvascular reactivity in 59 normotensives with a family history of hypertension and 46 controls. We measured laser‐Doppler flow on the finger nailfold skin in the resting condition, after an 8‐min occlusion of digital arteries and during local nitroglycerin application. Finger pressure, pulse and ECG were monitored by a Finapres device. Heart rate power spectral analysis was performed using Fast Fourier transformation. Baroreflex sensitivity was estimated by the sequence method. Normotensives with a family history of hypertension showed higher systolic pressure, decreased high‐frequency power of the heart rate variability spectrum and reduced baroreflex sensitivity in the resting condition as well as decreased fundamental frequency of laser‐Doppler flow oscillations during nitroglycerin application. We conclude that normotensives with a family history of hypertension exhibit altered sympathovagal balance with decreased parasympathetic activity at the cardiac level as well as increased myogenic microvascular reactivity.