Efektivita práce levé komory vyžaduje udržení srdečního výdeje, který je nárokován systémovým oběhem, a to bez vysokých metabolických nároků nebo nároků na kyslík ze strany myokardu levé komory. V tomto článku je levá komora uvažována jako pumpa a výkonnost je založena na hodnocení měření jejích tlaků, objemů a průtoku. Analýza funkce komory z hlediska vztahů mezi tlakem a objemem umožňuje plně analyzovat globální a regionální dynamiku komory, kterou lze poměrně snadno a přesně získat pomocí vodivostního katétru. Maximální změna tlaku za jednotku času v levé komoře je považována za ukazatel kontraktility levé komory, za jistých situací může být alternativou arteriální dP/dt max jakožto méně invazivní metoda. Při hodnocení nových kardiostimulačních technik a srdeční resynchronizační terapie se jako nejpraktičtější metoda jeví invazivní systolický krevní tlak s průměrováním více tepů a doplněním o několikrát opakované střídání stimulací
Effective performance of the left ventricle requires the maintenance of a cardiac output as demanded by the systemic circulation without a high hemodynamic cost or pressure and without a high metabolic cost or oxygen demand by the left ventricular myocardium. In this article the left ventricle is considered as a pump and performance is based on evaluation of measurements of its pressure, volumes, and flow. Analysis of ventricular function in terms of pressure-volume relationships allows global and regional ventricular dynamics to be fully analyzed and relatively easily and precisely obtained with conductance catheter. The maximum rate of left ventricular pressure is classically considered as a marker of left ventricular contractility and in specific situation arterial dP/dtmax, as minimally invasive method, can be an alternative. When assessing new pacing techniques and cardiac resynchronization therapy, invasive systolic blood pressure appears to be the most practical measure with multi-beat averaging and the addition of multiple spaced repeated alternations.
- Klíčová slova
- dP/dtmax, Srdeční funkce,
- MeSH
- diagnostické techniky kardiovaskulární klasifikace MeSH
- funkce levé komory srdeční * MeSH
- hemodynamika MeSH
- kontrakce myokardu fyziologie MeSH
- krevní tlak MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
The pressure-volume (PV) analysis is used for an accurate assessment of load-independent cardiac function and is important for the study of cardiovascular diseases and various therapeutic modalities. PV analysis is often performed on one of the ventricles, or on both ventricles but sequentially. Since both ventricles interact with each other and their functions are mutually interdependent, especially in various disease conditions such as pulmonary hypertension or heart failure, it is important to quantify the function of both ventricles at the same time. Therefore, our aim was to describe a standardized protocol for simultaneous right (RV) and left (LV) ventricle of PV analysis, including an especially controllable preload reduction manoeuver. Our second aim was to test whether simultaneous catheterization of both LV and RV is necessary for the determination of biventricular PV relationship compared to sequential measurement of both ventricles separately. In this article, we showed the feasibility and the value of simultaneous biventricular PV analysis in the measurement of contractility parameters (end-systolic pressure-volume relationship (ESPVR), ventricular pressure over time (dP/dt)max, divided by end-diastolic volume (dP/dt max-EDV)) with a comparison to the sequential measurement of the RV and LV ventricles separately. We described in detail the protocol for simultaneous biventricular PV analysis in rats using a pair of conductance-micromanometer catheters with a preload-reducing manoeuver using balloon catheter inflation in the inferior vena cava. We also described technical tips and show examples of PV loop data obtained in normotensive and hypertensive rats, with and without heart failure due to volume overload. This protocol could be useful for scientists studying hemodynamics and cardiac contractility in various models of cardiovascular diseases with a focus on biventricular differences and ventricular interdependence.
BACKGROUND: The role of pulse pressure (PP) 'widening' at older and younger age as a cardiovascular risk factor is still controversial. Mean PP, as determined from repeated blood pressure (BP) readings, can be expressed as a sum of two components: 'elastic PP' (elPP) and 'stiffening PP' (stPP) associated, respectively, with stiffness at the diastole and its relative change during the systole. We investigated the association of 24-h ambulatory PP, elPP, and stPP ('PP variables') with mortality and composite cardiovascular events in different age classes. METHOD: Longitudinal population-based cohort study of adults with baseline observations that included 24-h ambulatory BP. Age classes were age 40 or less, 40-50, 50-60, 60-70, and over 70 years. Co-primary endpoints were total mortality and composite cardiovascular events. The relative risk expressed by hazard ratio per 1SD increase for each of the PP variables was calculated from multivariable-adjusted Cox regression models. RESULTS: The 11 848 participants from 13 cohorts (age 53 ± 16 years, 50% men) were followed for up for 13.7 ± 6.7 years. A total of 2946 participants died (18.1 per 1000 person-years) and 2093 experienced a fatal or nonfatal cardiovascular event (12.9 per 1000 person-years). Mean PP, elPP, and stPP were, respectively, 49.7, 43.5, and 6.2 mmHg, and elPP and stPP were uncorrelated ( r = -0.07). At age 50-60 years, all PP variables displayed association with risk for almost all outcomes. From age over 60 years to age over 70 years, hazard ratios of of PP and elPP were similar and decreased gradually but differently for pulse rate lower than or higher than 70 bpm, whereas stPP lacked predictive power in most cases. For age 40 years or less, elPP showed protective power for coronary events, whereas stPP and PP predicted stroke events. Adjusted and unadjusted hazard ratio variations were similar over the entire age range. CONCLUSION: This study provides a new basis for associating PP components with outcome and arterial properties in different age groups and at different pulse rates for both old and young age. The similarity between adjusted and unadjusted hazard ratios supports the clinical usefulness of PP components but further studies are needed to assess the prognostic significance of the PP components, especially at the young age.
- MeSH
- ambulantní monitorování krevního tlaku MeSH
- dospělí MeSH
- hypertenze * MeSH
- kardiovaskulární nemoci * diagnóza MeSH
- kohortové studie MeSH
- krevní tlak fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- systola fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Based on the World Health Organization statistics, cardiovascular diseases represent the major cause of death worldwide. Although a wide range of treatment approaches and pharmaceuticals is available, the therapy is often not effective enough and therefore health risks for the patient persist. Thus, it is still essential to test new drug candidates for the treatment of various pathophysiological conditions related to cardiovascular system. In vivo models represent indispensable part of preclinical testing of such substances. Anesthetized guinea pig as a whole-body model allows to evaluate complex reactions of cardiovascular system to tested substance. Moreover, action potential of guinea pig cardiomyocyte is quite comparable to that of human. Hence, the results from this model are then quite well translatable to clinical medicine. Aim of this paper was to summarize the methodology of this model, including its advantages and/or limitations and risks, based on the effects of two substances with adrenergic activity on the ECG parameters. The model of anesthetized guinea pig proved to be valuable and suitable for testing of drugs with cardiovascular effects.
- MeSH
- elektrokardiografie * MeSH
- kardiovaskulární systém * účinky léků MeSH
- kontrakce myokardu * účinky léků fyziologie MeSH
- krevní tlak účinky léků MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- morčata MeSH
- preklinické hodnocení léčiv * MeSH
- srdce účinky léků fyziologie MeSH
- srdeční frekvence MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- morčata MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
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
PURPOSE: Echocardiography is a common tool for cardiac and hemodynamic assessments in critical care research. However, interpretation (and applications) of results and between-study comparisons are often difficult due to the lack of certain important details in the studies. PRICES (Preferred Reporting Items for Critical care Echocardiography Studies) is a project endorsed by the European Society of Intensive Care Medicine and conducted by the Echocardiography Working Group, aiming at producing recommendations for standardized reporting of critical care echocardiography (CCE) research studies. METHODS: The PRICE panel identified lists of clinical and echocardiographic parameters (the "items") deemed important in four main areas of CCE research: left ventricular systolic and diastolic functions, right ventricular function and fluid management. Each item was graded using a critical index (CI) that combined the relative importance of each item and the fraction of studies that did not report it, also taking experts' opinion into account. RESULTS: A list of items in each area that deemed essential for the proper interpretation and application of research results is recommended. Additional items which aid interpretation were also proposed. CONCLUSION: The PRICES recommendations reported in this document, as a checklist, represent an international consensus of experts as to which parameters and information should be included in the design of echocardiography research studies. PRICES recommendations provide guidance to scientists in the field of CCE with the objective of providing a recommended framework for reporting of CCE methodology and results.
BACKGROUND: The selective cardiac myosin activator omecamtiv mecarbil has been shown to improve cardiac function in patients with heart failure with a reduced ejection fraction. Its effect on cardiovascular outcomes is unknown. METHODS: We randomly assigned 8256 patients (inpatients and outpatients) with symptomatic chronic heart failure and an ejection fraction of 35% or less to receive omecamtiv mecarbil (using pharmacokinetic-guided doses of 25 mg, 37.5 mg, or 50 mg twice daily) or placebo, in addition to standard heart-failure therapy. The primary outcome was a composite of a first heart-failure event (hospitalization or urgent visit for heart failure) or death from cardiovascular causes. RESULTS: During a median of 21.8 months, a primary-outcome event occurred in 1523 of 4120 patients (37.0%) in the omecamtiv mecarbil group and in 1607 of 4112 patients (39.1%) in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.86 to 0.99; P = 0.03). A total of 808 patients (19.6%) and 798 patients (19.4%), respectively, died from cardiovascular causes (hazard ratio, 1.01; 95% CI, 0.92 to 1.11). There was no significant difference between groups in the change from baseline on the Kansas City Cardiomyopathy Questionnaire total symptom score. At week 24, the change from baseline for the median N-terminal pro-B-type natriuretic peptide level was 10% lower in the omecamtiv mecarbil group than in the placebo group; the median cardiac troponin I level was 4 ng per liter higher. The frequency of cardiac ischemic and ventricular arrhythmia events was similar in the two groups. CONCLUSIONS: Among patients with heart failure and a reduced ejection, those who received omecamtiv mecarbil had a lower incidence of a composite of a heart-failure event or death from cardiovascular causes than those who received placebo. (Funded by Amgen and others; GALACTIC-HF ClinicalTrials.gov number, NCT02929329; EudraCT number, 2016-002299-28.).
- MeSH
- kardiotonika škodlivé účinky farmakologie terapeutické užití MeSH
- kardiovaskulární nemoci mortalita MeSH
- kontrakce myokardu účinky léků MeSH
- lidé středního věku MeSH
- lidé MeSH
- močovina škodlivé účinky analogy a deriváty farmakologie terapeutické užití MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- srdeční myosiny účinky léků metabolismus MeSH
- systolické srdeční selhání farmakoterapie metabolismus patofyziologie MeSH
- tepový objem MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky, fáze III MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
Budoucností léčby srdečního selhání jsou metody, které si kladou za cíl zpomalit, případně zvrátit nepříznivý progresivní vývoj onemocnění. U nemocných v méně pokročilých stadiích srdečního selhání probíhá výzkum v možnosti ovlivnění autonomní regulace a procesu srdeční remodelace u HFrEF. Nové intervenční metody se testují také u nemocných s HFpEF.
The future of the treatment of heart failure is based on methods aimed at slowing or reversing the progressive course of the disease. In patients in a less advanced stage of heart failure, the research is focused on the modulation of autonomic regulation and cardiac remodeling in HFrEF. New interventional methods are also tested in patients with HFpEF.
- Klíčová slova
- rozštěp, klapnutí, Valsavův manévr,
- MeSH
- aortální insuficience diagnóza klasifikace patofyziologie patologie MeSH
- aortální stenóza diagnóza etiologie patofyziologie patologie MeSH
- břicho patologie MeSH
- cyanóza diagnóza etiologie klasifikace patofyziologie patologie MeSH
- defekty komorového septa diagnóza patologie MeSH
- defekty septa síní diagnóza patofyziologie patologie MeSH
- diastola fyziologie MeSH
- diferenciální diagnóza MeSH
- Ebsteinova anomálie diagnóza patofyziologie patologie MeSH
- Eisenmengerův syndrom diagnóza patologie MeSH
- Fallotova tetralogie diagnóza patologie MeSH
- fyzikální vyšetření * klasifikace MeSH
- hlava patologie MeSH
- hrudník patologie MeSH
- insuficience plicnice diagnóza patofyziologie patologie MeSH
- koarktace aorty diagnóza patofyziologie patologie MeSH
- končetiny patologie MeSH
- kontrakce myokardu fyziologie MeSH
- kožní manifestace MeSH
- krk patologie MeSH
- lidé MeSH
- mitrální insuficience diagnóza etiologie klasifikace patofyziologie patologie MeSH
- mitrální stenóza diagnóza etiologie patofyziologie patologie MeSH
- nemoci srdce * diagnóza etiologie klasifikace patofyziologie patologie MeSH
- nemoci srdečních chlopní diagnóza etiologie klasifikace patofyziologie patologie MeSH
- obstrukce výtoku ze srdeční komory diagnóza patologie MeSH
- otevřená tepenná dučej diagnóza patofyziologie patologie MeSH
- palpace MeSH
- perikarditida diagnóza patologie MeSH
- perkuse klasifikace MeSH
- poslech srdce MeSH
- poslech MeSH
- postura těla fyziologie MeSH
- pulz klasifikace MeSH
- šelest na srdci diagnóza etiologie klasifikace patologie MeSH
- srdce - funkce komor MeSH
- srdce - funkce síní MeSH
- srdce patofyziologie MeSH
- srdeční chlopně umělé klasifikace MeSH
- srdeční ozvy fyziologie MeSH
- srdeční selhání diagnóza etiologie klasifikace patofyziologie patologie MeSH
- stenóza pulmonální chlopně diagnóza patologie MeSH
- stetoskopy MeSH
- systola fyziologie MeSH
- trikuspidální insuficience diagnóza etiologie patologie MeSH
- trikuspidální stenóza diagnóza patologie MeSH
- venae jugulares patologie MeSH
- vrozené srdeční vady diagnóza klasifikace patofyziologie patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
