Influence of age and gender on the phase and strength of the relation between heart period and systolic blood pressure spontaneous fluctuations

Abstract

Aging affects baroreflex regulation. The effect of senescence on baroreflex control was assessed from spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP) through the HP-SAP gain, while the HP-SAP phase and strength are usually disregarded. This study checks whether the HP-SAP phase and strength, as estimated, respectively, via the phase of the HP-SAP cross spectrum (Ph) and squared coherence function (K), vary with age in healthy individuals and trends are gender-dependent. We evaluated 110 healthy volunteers (55 males) divided into five age subgroups (21-30, 31-40, 41-50, 51-60, and 61-70 yr). Each subgroup was formed by 22 subjects (11 males). HP series was extracted from electrocardiogram and SAP from finger arterial pressure at supine resting (REST) and during active standing (STAND). Ph and K functions were sampled in low-frequency (LF, from 0.04 to 0.15 Hz) and in high-frequency (HF, above 0.15 Hz) bands. Both at REST and during STAND Ph(LF) showed a negative correlation with age regardless of gender even though values were more negative in women. This trend was shown to be compatible with a progressive increase of the baroreflex latency with age. At REST K(LF) decreased with age regardless of gender, but during STAND the high values of K(LF) were more preserved in men than women. At REST and during STAND the association of Ph(HF) and K(HF) with age was absent. The findings points to a greater instability of baroreflex control with age that seems to affect to a greater extent women than men. NEW & NOTEWORTHY Aging increases cardiac baroreflex latency and decreases the degree of cardiac baroreflex involvement in regulating cardiovascular variables. These trends are gender independent but lead to longer delays and asmaller degree of cardiac baroreflex involvement in women than in men, especially during active standing, with important implications on the tolerance to an orthostatic stressor.

A Transfer Entropy Approach for the Assessment of the Impact of Inspiratory Muscle Training on the Cardiorespiratory Coupling of Amateur Cyclists

“…Signals were sampled at 1000 Hz (Power Lab 8/35, ADInstruments, Australia). Recording sessions were carried out at the Cardiovascular Physical Therapy Laboratory, Department of Physical Therapy, UFSCar, São Carlos, Brazil according to standardized criteria minimizing individual and environmental factors that might increase the variance of cardiovascular control markers (Milan-Mattos et al, 2018). Subjects were initially maintained at REST for 10 min to stabilize the cardiovascular variables.…”

“…More specifically, we defined as HP-SAP pattern of baroreflex origin an HP-SAP joint scheme featuring three consecutive and contemporaneous HP and SAP increases or decreases. Therefore, an HP-SAP pattern of baroreflex origin is characterized by same-sign HP and SAP ramps with a delay between them equal to 0 beats, thus focusing on the fast vagal arm of the cardiac baroreflex featuring very short latencies compatible with the measurement convention adopted in this study (Eckberg, 1976;Milan-Mattos et al, 2018). All the detected HP-SAP patterns of baroreflex origin were retained in this analysis regardless of the magnitude of total, or partial, SAP and HP variations and the strength of the linear association between HP and SAP values (Porta et al, 2013a).…”

“…The computation of the CRC strength (CRCS), namely the degree of association between HP and respiration in the time direction from respiration to HP, is of paramount importance because it decreases with age (Iatsenko et al, 2013;Porta et al, 2014) and this decline provides information complementary to that derived from different autonomic control markers such as RSA (Laitinen et al, 2004;Beckers et al, 2006), cardiac baroreflex sensitivity (Laitinen et al, 1998;Milan-Mattos et al, 2018), cardiac control complexity (Kaplan et al, 1991;Catai et al, 2014) and the gain of the relation from respiration to HP (Saul et al, 1991). The relevance of assessing CRCS is further outlined by the well-known finding that it declines in situations evoking a high sympathetic tone and/or modulation such as during postural challenges (Porta et al, 2012 and it is altered in pathological conditions (Garcia et al, 2013;Schulz et al, 2013Schulz et al, , 2015Riedl et al, 2014;Penzel et al, 2016).…”

Baroreflex sensitivity in frailty syndrome

“…In the aging process, a decline in baroreflex sensitivity (BRS) is expected (9,10). Therefore, there is a reduction of HR responsiveness as a counterpoint to acute changes of BP and a decrease of the baroreflex capacity in buffering changes in systemic BP (8).…”

Autonomic Control of the Heart and Its Clinical Impact. A Personal Perspective

“…A wealth of non-invasive indicators of the arterial-cardiac baroreceptor reflex sensitivity can be obtained by the joint analysis of beat-to-beat spontaneous fluctuations of systolic blood pressure and RR interval series ( La Rovere et al, 2008 ). These methods include: model-free techniques ( Robbe et al, 1987 ; Pinna et al, 2002 ), interactions among heart period and systolic arterial pressure ( Porta et al, 2000 ; Nollo et al, 2005 ; Milan-Mattos et al, 2018 ), models searching for specific patterns of baroreflex origin ( Bertinieri et al, 1985 ) or heart rate responses to systolic pressure changes ( Bauer et al, 2010 ), and others merely requiring a certain degree of association between spontaneous heart period and systolic arterial pressure variations ( Westerhof et al, 2004 ). Some methods lead to an indirect estimate of BRS via analysis of the bi-phasic response of the sinus node to a premature ventricular contraction (named heart rate turbulence) that is largely dependent on the baroreflex ( Schmidt et al, 1999 ; La Rovere et al, 2011 ).…”