Cardiac Autonomic Response to Active Standing in Calcific Aortic Valve Stenosis.

José M Torres-Arellano,Oscar Infante,Erika Fajardo,Rafael Bojalil,Rashidi Springall,Juan C Echeverría,Nydia Ávila-Vanzzini,Claudia Lerma,Jorge E Cossío-Aranda,Andrea Toledo

doi:10.3390/jcm10092004

Abstract

Aortic stenosis is a progressive heart valve disorder characterized by calcification of the leaflets. Heart rate variability (HRV) analysis has been proposed for assessing the heart response to autonomic activity, which is documented to be altered in different cardiac diseases. The objective of the study was to evaluate changes of HRV in patients with aortic stenosis by an active standing challenge. Twenty-two volunteers without alterations in the aortic valve (NAV) and twenty-five patients diagnosed with moderate and severe calcific aortic valve stenosis (AVS) participated in this cross-sectional study. Ten minute electrocardiograms were performed in a supine position and in active standing positions afterwards, to obtain temporal, spectral, and scaling HRV indices: mean value of all NN intervals (meanNN), low-frequency (LF) and high-frequency (HF) bands spectral power, and the short-term scaling indices (α1 and αsign1). The AVS group showed higher values of LF, LF/HF and αsign1 compared with the NAV group at supine position. These patients also expressed smaller changes in meanNN, LF, HF, LF/HF, α1, and αsign1 between positions. In conclusion, we confirmed from short-term recordings that patients with moderate and severe calcific AVS have a decreased cardiac parasympathetic supine response and that the dynamic of heart rate fluctuations is modified compared to NAV subjects, but we also evidenced that they manifest reduced autonomic adjustments caused by the active standing challenge.

Highlights

By evaluating the heart rate variability in patients with calcified aortic valve stenosis (AVS), in short recordings and during controlled activity conditions, we confirmed that patients at supine position show a less predominant cardiac response to the parasympathetic modulation in comparison with a healthy valve group (NAV)
We identified a dynamic behavior of Heart rate variability (HRV) that reflects less anticorrelation in AVS at the supine position
We confirmed in short-term recordings that patients with AVS have a decreased cardiac parasympathetic supine response compared to normal aortic valve (NAV) subjects, but we evidenced that they manifest reduced HRV adjustments caused by the active standing challenge

Summary

Introduction

The diagnosis of aortic valve stenosis (AVS). Is secondary to the first signs or symptoms during the advanced stages of the disease, when mortality risk is very high if an aortic valve replacement surgery is not carried out [3]. The modulation exerted by the autonomic nervous system is considered to have a crucial role in the adequate response of blood vessels and heart activity to both daily and unexpected challenges [7]. Notwithstanding that autonomic modulation provides the cardiovascular system with significant adaptive responses, its impairment could be involved in the etiology or progression of several cardiovascular diseases [8,9]. In essential hypertension, predominance of the sympathetic nervous system seems to initiate or sustain the arterial stiffness and rigidity, combined with higher inotropic and chronotropic activity of the heart [10]

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