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Journal of Cardiology Jun 2019Diastolic filling of the heart is a complex sequence of multiple inter-related events consisting of processes such as ventricular relaxation, erectile coronary effect,... (Review)
Review
Diastolic filling of the heart is a complex sequence of multiple inter-related events consisting of processes such as ventricular relaxation, erectile coronary effect, visco-elastic forces of the myocardium, ventricular interaction, myocardial stress strain relationships, pericardial restraint, passive filling, and atrial contraction. However, in order to understand diastolic filling from a clinical aspect, a simplified foundation can be used which divides the cardiac cycle into contraction, relaxation, passive filling, and filling at atrial contraction. The mitral flow velocity curves are representative of the relative driving pressure between left atrium and left ventricle and allow one to grade the progression of diastolic dysfunction which occurs in disease states. Doppler tissue imaging is necessary as a surrogate of ventricular relaxation to further determine the stages of diastolic dysfunction in patients with preserved ejection fraction. These Doppler flow velocity curves can be applied to understanding diastolic filling of the heart in patients with both reduced ejection fraction and preserved ejection fraction.
Topics: Cardiomyopathies; Diastole; Echocardiography, Doppler; Female; Heart Atria; Heart Ventricles; Humans; Male; Myocardial Contraction; Ventricular Dysfunction; Ventricular Function
PubMed: 30922613
DOI: 10.1016/j.jjcc.2019.03.002 -
Physiological Reports Oct 2021Three-dimensional echocardiography can elucidate the phasic functions of the left atrium if a simultaneous acquisition of a pyramidal full-volume dataset, as gathered... (Review)
Review
Three-dimensional echocardiography can elucidate the phasic functions of the left atrium if a simultaneous acquisition of a pyramidal full-volume dataset, as gathered from the apical window and containing the entire left atrial and left ventricular cardiac sections, is obtained. Hence, conduit can be quantified as the integral of net, diastolic, instantaneous difference between synchronized atrial and ventricular volume curves, beginning at minimum ventricular cavity volume and ending just before atrial contraction. Increased conduit can reflect increased downstream suction, as conduit would track the apex-to-base intracavitary pressure gradient existing, in early diastole, within the single chamber formed by the atrium and the ventricle, when the mitral valve is open. Such a gradient increases in response to adrenergic stimulation or during exercise and mediates an increment in passive flow during early diastole, with the ventricle being filled from the atrial reservoir and, simultaneously, from blood drawn from the pulmonary veins. In this context conduit, and even more conduit flow rate, expressed in ml/sec, can be viewed as an indirect marker of left ventricular relaxation. It is well known, however, that a large amount of conduit (in relative terms) is also supposed to contribute to LV stroke volume in conditions of increased resistance to LV filling, when diastolic function significantly worsens. Stiffening of the atrio-ventricular complex implies increments in LA pressure more pronounced in late systole, causing markedly elevated "v" waves, independently of the presence of mitral insufficiency. The combination of increased atrio-ventricular stiffness and conduit flow is associated with an elevation of the right ventricular pulsatile relative to resistive load that negatively impacts on exercise capacity and survival in these patients. Atrial conduit is an "intriguing" parameter that conveys a noninvasive picture of the complex atrioventricular coupling condition in diastole and its backward effects on the right side of the heart and the pulmonary circulation. Given the easiness associated with its correctly performed quantification in the imaging laboratory, I am sure that conduit will survive the competitive access to the list of valuable parameters capable of deciphering, although not necessarily simplifying, the complex diastolic scenario in health and disease.
Topics: Atrial Function, Left; Diastole; Echocardiography, Three-Dimensional; Heart Atria; Humans; Stroke Volume
PubMed: 34605214
DOI: 10.14814/phy2.15053 -
Fluids and Barriers of the CNS Sep 2023Since arterial flow is the leading actor in neuro-fluids flow dynamics, it might be interesting to assess whether it is meaningful to study the arterial flow waveform in...
BACKGROUND
Since arterial flow is the leading actor in neuro-fluids flow dynamics, it might be interesting to assess whether it is meaningful to study the arterial flow waveform in more detail and whether this provides new important information. Few studies have focused on determining the influence of heart rate variation over time on the arterial flow curve. Therefore, this study aimed to evaluate cerebral arterial flow waveforms at extracranial and intracranial compartments in young and elderly healthy adults, also considering systole and diastole phases.
METHODS
Cine phase-contrast magnetic resonance imaging (CINE-PC MRI) was performed on twenty-eight healthy young volunteers (HYV) and twenty healthy elderly volunteers (HEV) to measure arterial blood flows at the extracranial and intracranial planes. A semi-automated protocol using MATLAB scripts was implemented to identify the main representative points in the arterial flow waveforms. Representative arterial profiles were estimated for each group. Moreover, the effects of age and sex on flow times, amplitude-related parameters, and parameters related to systole and diastole phases were evaluated at the extracranial and intracranial compartments. Student's t-test or Wilcoxon's test (depending on the normality of the distribution) was used to detect significant differences.
RESULTS
In HYVs, significant differences were observed between extracranial and intracranial levels in parameters related to the AP1 amplitude. Besides the detected differences in pulsatility index (extracranial: 0.92 ± 0.20 vs. 1.28 ± 0.33; intracranial: 0.79 ± 0.15 vs. 1.14 ± 0.18, p < .001) and average flow (715 ± 136 vs. 607 ± 125 ml/min, p = .008) between HYV and HEV, differences in the amplitude value of the arterial flow profile feature points were also noted. Contrary to systole duration (HYV: 360 ± 29 ms; HEV: 364 ± 47 ms), diastole duration presented higher inter-individual variability in both populations (HYV: 472 ± 145 ms; HEV: 456 ± 106 ms). Our results also showed that, with age, it is mainly the diastolic phase that changes. Although no significant differences in duration were observed between the two populations, the mean flow value in the diastolic phase was significantly lower in HEV (extracranial: 628 ± 128 vs. 457 ± 111 ml/min; intracranial: 599 ± 121 vs. 473 ± 100 ml/min, p < .001). No significant differences were observed in the arterial flow parameters evaluated between females and males in either HYV or HEV.
CONCLUSION
Our study provides a novel contribution on the influence of the cardiac cycle phases on cerebral arterial flow. The main contribution in this study concerns the identification of age-related alterations in cerebral blood flow, which occur mainly during the diastolic phase. Specifically, we observed that mean flow significantly decreases with age during diastole, whereas mean flow during systole is consistent.
Topics: Aged; Female; Male; Humans; Adult; Diastole; Systole; Cerebrovascular Circulation; Healthy Volunteers; Heart Rate
PubMed: 37705096
DOI: 10.1186/s12987-023-00467-8 -
Hypertension (Dallas, Tex. : 1979) Apr 2017
Topics: Diastole; Heart; Heart Failure; Humans; Systole
PubMed: 28223470
DOI: 10.1161/HYPERTENSIONAHA.116.08849 -
Circulation Journal : Official Journal... Jun 2020
Topics: Blood Pressure; Diastole; Fractional Flow Reserve, Myocardial
PubMed: 32507802
DOI: 10.1253/circj.CJ-20-0485 -
Journal of the American Society of... Sep 2022Parameters of the interaction of the left atrium and left ventricle, atrioventricular (AV) coupling, are used in the diagnosis and follow-up of diastolic dysfunction in...
BACKGROUND
Parameters of the interaction of the left atrium and left ventricle, atrioventricular (AV) coupling, are used in the diagnosis and follow-up of diastolic dysfunction in adults. Pediatric parameters of AV coupling have not been evaluated so far. The aim of this multicenter study was to investigate parameters of AV coupling in a large cohort of healthy infants and children using noninvasive real-time three-dimensional echocardiography. The authors hypothesized that the contribution of the different left atrial (LA) volumes to left ventricular (LV) stroke volume differs over a range of different heart rates.
METHODS
Three-dimensional echocardiographic data sets from 332 subjects (ages 0 days to 18.5 years) were analyzed prospectively. Volume-time curves of the left atrium and left ventricle were generated. Conduit volume was calculated and percentiles were established by the lambda-mu-sigma method of Cole and Green. Contributions of active, passive, and conduit volume to LV filling were measured and related to heart rate by linear regression. LV and LA peak filling rates (PFR) and peak emptying rates (PER) and time to PFR and PER normalized to the R-R interval (PFR[%] and PER[%]) were measured and correlated to each other.
RESULTS
Conduit volume increased with body surface area. The contribution of LA active emptying to LV filling tended to increase with decreasing heart rate, while the contribution of passive emptying decreased. Conduit volume contributed most to LV filling (median, 57.58 %; interquartile range, 12.85%) with a tendency to increase with decreasing heart rate. Close diastolic AV coupling was demonstrated by virtually identical LV PFR(%) and LA PER(%) during diastole. LV PER(%) occurred earlier than LA PFR(%), showing less coupling during systole. LV PFR(%) and LA PER(%) were strongly correlated to heart rate (r = 0.76 and r = 0.73, respectively). Lower heart rate resulted in a prolongation of diastole after LV PFR.
CONCLUSIONS
Assessment of conduit volume and AV coupling by three-dimensional echocardiography is feasible in infants and children. The references of this study can serve as a basis to further investigate the role of parameters of AV coupling in pediatric patients with heart diseases concerning diastolic and LA function.
Topics: Adult; Atrial Function, Left; Child; Diastole; Echocardiography, Three-Dimensional; Heart Atria; Humans; Infant, Newborn; Stroke Volume; Ventricular Dysfunction, Left; Ventricular Function, Left
PubMed: 35537616
DOI: 10.1016/j.echo.2022.04.014 -
Physiological Reports Apr 2024Investigating ventricular diastolic properties is crucial for understanding the physiological cardiac functions in organisms and unraveling the pathological mechanisms... (Review)
Review
Investigating ventricular diastolic properties is crucial for understanding the physiological cardiac functions in organisms and unraveling the pathological mechanisms of cardiovascular disorders. Ventricular stiffness, a fundamental parameter that defines ventricular diastolic functions in chordates, is typically analyzed using the end-diastolic pressure-volume relationship (EDPVR). However, comparing ventricular stiffness accurately across chambers of varying maximum volume capacities has been a long-standing challenge. As one of the solutions to this problem, we propose calculating a relative ventricular stiffness index by applying an exponential approximation formula to the EDPVR plot data of the relationship between ventricular pressure and values of normalized ventricular volume by the ventricular weight. This article reviews the potential, utility, and limitations of using normalized EDPVR analysis in recent studies. Herein, we measured and ranked ventricular stiffness in differently sized and shaped chambers using ex vivo ventricular pressure-volume analysis data from four animals: Wistar rats, red-eared slider turtles, masu salmon, and cherry salmon. Furthermore, we have discussed the mechanical effects of intracellular and extracellular viscoelastic components, Titin (Connectin) filaments, collagens, physiological sarcomere length, and other factors that govern ventricular stiffness. Our review provides insights into the comparison of ventricular stiffness in different-sized ventricles between heterologous and homologous species, including non-model organisms.
Topics: Animals; Rats; Diastole; Heart Ventricles; Species Specificity; Ventricular Function; Turtles; Salmon
PubMed: 38644486
DOI: 10.14814/phy2.16013 -
JACC. Cardiovascular Imaging Nov 2017
Topics: Diastole; Heart Ventricles; Vascular Stiffness
PubMed: 28330671
DOI: 10.1016/j.jcmg.2016.11.017 -
Revista Portuguesa de Cardiologia Oct 2021
Topics: Diabetes Mellitus, Type 1; Diastole; Humans; Ventricular Dysfunction, Left
PubMed: 34857115
DOI: 10.1016/j.repce.2021.10.007 -
European Journal of Heart Failure Aug 2002increasing evidence supports the existence of left ventricular diastolic dysfunction as an important cause of congestive heart failure, present in up to 40% of heart... (Review)
Review
BACKGROUND
increasing evidence supports the existence of left ventricular diastolic dysfunction as an important cause of congestive heart failure, present in up to 40% of heart failure patients.
AIM
to review the pathophysiology of LV diastolic dysfunction and diastolic heart failure and the currently available methods to diagnose these disorders.
RESULTS
for diagnosing LV diastolic dysfunction, invasive hemodynamic measurements are the gold standard. Additional exercise testing with assessment of LV volumes and pressures may be of help in detecting exercise-induced elevation of filling pressures because of diastolic dysfunction. However, echocardiography is obtained more easily, and will remain the most often used method for diagnosing diastolic heart failure in the coming years. MRI may provide noninvasive determination of LV three-dimensional motion during diastole, but data on correlation of MRI data with clinical findings are scant, and possibilities for widespread application are limited at this moment.
CONCLUSIONS
in the forthcoming years, optimal diagnostic and therapeutic strategies for patients with primary diastolic heart failure have to be developed. Therefore, future heart failure trials should incorporate patients with diastolic heart failure, describing precise details of LV systolic and diastolic function in their study populations.
Topics: Diastole; Echocardiography; Exercise Test; Heart Failure; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Contraction; Ventricular Dysfunction, Left
PubMed: 12167379
DOI: 10.1016/s1388-9842(02)00020-x