Arterial compliance (C) is a complex parameter influencing ventricular-arterial coupling depending on structural (arterial wall remodeling) and functional (blood pressure, smooth muscles tone) changes. Based on Windkessel model, C can be calculated as the ratio of a time constant Tau characterizing diastolic blood pressure decay and total peripheral resistance (TPR). The aim of this study was to assess changes of C in the context of systolic arterial pressure (SAP) perturbations during four physiological states (supine rest, head-up tilt, supine recovery, mental arithmetic). In order to compare pressure independent changes of C a new index of C120 was proposed predicting C value at 120 mm Hg of SAP. Eighty-one healthy young subjects (48 f, average age 18.6 years) were examined. Hemodynamic parameters were measured beat-to-beat using volume-clamp photoplethysmographic method and impedance cardiography. We observed that C was strongly related to SAP values on the beat-to-beat time scale. Interestingly, C120 decreased significantly during stress phases. In conclusion, potential changes of SAP should be considered when measuring C. Arterial compliance changes in the opposite direction to TPR pointing towards influence of vascular tone changes on its value.
- MeSH
- arteriální tlak * MeSH
- časové faktory MeSH
- cévní rezistence MeSH
- fyziologická adaptace MeSH
- lidé MeSH
- matematické pojmy MeSH
- mladiství MeSH
- mladý dospělý MeSH
- modely kardiovaskulární MeSH
- polohování pacienta MeSH
- supinační poloha MeSH
- systola MeSH
- test na nakloněné rovině MeSH
- tuhost cévní stěny * MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Beta-adrenergic receptors (beta-ARs) play a pivotal role in the cardiovascular regulation. In the human heart beta1- and beta2-ARs dominate in atria as well as in ventricle influencing heart rate and myocardial contractility. Some single nucleotide polymorphisms (SNPs) of beta-ARs might influence cardiovascular function. However, the influence of beta-AR genes SNPs on hemodynamic parameters at rest and their reactivity under stress is still not well known. We aimed to explore the associations between four selected beta-ARs gene polymorphisms and selected cardiovascular measures in eighty-seven young healthy subjects. While in beta1-AR polymorphism rs1801252 no significant association was observed, second beta1-AR polymorphism rs1801253 was associated with decreased cardiac output and cardiac index during all phases and with decreased flow time corrected and ejection time index at rest and during mental arithmetics. Polymorphism rs1042713 in beta2-AR was associated with alterations in blood pressure variability at rest and during head-up-tilt, while rs1042714 was associated predominantly with decreased parameters of cardiac contractility at rest and during mental arithmetics. We conclude that complex analysis of various cardiovascular characteristics related to the strength of cardiac contraction and blood pressure variability can reveal subtle differences in cardiovascular sympathetic nervous control associated with beta-ARs polymorphisms.
- MeSH
- beta-1-adrenergní receptory genetika MeSH
- beta-2-adrenergní receptory genetika MeSH
- fenotyp MeSH
- funkce levé komory srdeční genetika MeSH
- genotyp MeSH
- jednonukleotidový polymorfismus * MeSH
- kontrakce myokardu genetika MeSH
- krevní tlak genetika MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Adrenergic receptors (ARs) are the primary targets of catecholamines released from the sympathetic nerve endings during their activation. ARs play a central role in autonomic nervous system and serve as important targets of widely used drugs. Several ARs gene polymorphisms were found to be associated with cardiovascular disease in previous clinical studies. Although more precise mechanism of the polymorphisms influence on autonomic control of cardiovascular system was studied in many previous physiological studies, their results are not unequivocal. This paper reviews the results of clinical and physiological studies focused on the impact of selected common single nucleotide polymorphisms of ARs genes involved in sympathetic control on cardiovascular system and its control. In summary, many studies assessed only a very limited range of cardiovascular control related parameters providing only very limited view on the complex cardiovascular control. The overview of partially contradicting results underlines a need to examine wider range of cardiovascular measures including their reactivity under various stress conditions requiring further study. It is expected that an effect of one given polymorphism is not very prominent, but it is suggested that even subtle differences in cardiovascular control could - on a longer time scale - lead to the development of severe pathological consequences.
