-
Journal of the American College of... Jan 2017In pulmonary hypertension, the right ventricle adapts to the increasing vascular load by enhancing contractility ("coupling") to maintain flow. Ventriculoarterial... (Review)
Review
In pulmonary hypertension, the right ventricle adapts to the increasing vascular load by enhancing contractility ("coupling") to maintain flow. Ventriculoarterial coupling implies that stroke volume changes little while preserving ventricular efficiency. Ultimately, a phase develops where ventricular dilation occurs in an attempt to limit the reduction in stroke volume, with uncoupling and increased wall stress as a consequence. With pressure-volume analysis, we separately describe the changing properties of the pulmonary vascular system and the right ventricle, as well as their coupling, as important concepts for understanding the changes that occur in pulmonary hypertension. On the basis of the unique properties of the pulmonary circulation, we show how all relevant physiological parameters can be derived using an integrative approach. Because coupling is maintained by hypertrophy until the end stage of the disease, when progressive dilation begins, right ventricular volume is the essential parameter to measure in follow-up of patients with pulmonary hypertension.
Topics: Cardiac Volume; Follow-Up Studies; Heart Ventricles; Humans; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Magnetic Resonance Imaging; Myocardial Contraction; Pulmonary Artery; Pulmonary Circulation; Risk Factors; Stroke Volume
PubMed: 28081831
DOI: 10.1016/j.jacc.2016.10.047 -
Progress in Biophysics and Molecular... Jan 2021Well over a century ago, Otto Frank, working at Carl Ludwig's Institute of Physiology in Munich, studying the isolated, blood-perfused, frog heart preparation,... (Review)
Review
Well over a century ago, Otto Frank, working at Carl Ludwig's Institute of Physiology in Munich, studying the isolated, blood-perfused, frog heart preparation, demonstrated that there are two distinct pressure-volume relations in the heart: one for isovolumic twitches and a second (located inferiorly) for afterloaded twitches. Whereas Starling, working at UCL two decades later, referenced Frank's publication (to the extent of re-printing its seminal Figure), he appeared not to have tested Frank's finding. Hence, he remained silent with respect to Franks' contention that cardiac pressure-volume relations are contraction-mode-dependent. Instead, he concluded that "The energy of contraction, however measured, is a function of the length of the muscle fibre" - a conclusion that has become known (at least in the English-speaking world) as 'Starling's Law of the Heart'. This provides us with at least three conundra: (i) why did Starling present only one pressure-volume relation whereas Frank had previously found two, (ii) why, then, do we speak of The Frank-Starling relation, and (iii) how did Frank become largely forgotten for twelve decades among English speakers? This review will attempt to address and comment on these conundra.
Topics: Blood Pressure; Cardiac Output; Cardiac Volume; Heart; History, 19th Century; History, 20th Century; Humans; Models, Cardiovascular; Myocardial Contraction
PubMed: 32407748
DOI: 10.1016/j.pbiomolbio.2020.04.003 -
Cardiovascular Ultrasound Feb 2018Cardiac function is about creating and sustaining blood in motion. This is achieved through a proper sequence of myocardial deformation whose final goal is that of... (Review)
Review
Cardiac function is about creating and sustaining blood in motion. This is achieved through a proper sequence of myocardial deformation whose final goal is that of creating flow. Deformation imaging provided valuable contributions to understanding cardiac mechanics; more recently, several studies evidenced the existence of an intimate relationship between cardiac function and intra-ventricular fluid dynamics. This paper summarizes the recent advances in cardiac flow evaluations, highlighting its relationship with heart wall mechanics assessed through the newest techniques of deformation imaging and finally providing an opinion of the most promising clinical perspectives of this emerging field. It will be shown how fluid dynamics can integrate volumetric and deformation assessments to provide a further level of knowledge of cardiac mechanics.
Topics: Blood Flow Velocity; Cardiac Volume; Echocardiography; Heart; Heart Diseases; Hemodynamics; Humans; Hydrodynamics; Magnetic Resonance Imaging; Regional Blood Flow; Ventricular Function, Left
PubMed: 29458381
DOI: 10.1186/s12947-018-0122-2 -
Alimentary Pharmacology & Therapeutics Jun 2016
Topics: Cardiac Volume; Follow-Up Studies; Humans; Hypertension, Portal; Hypertension, Pulmonary; Portasystemic Shunt, Transjugular Intrahepatic
PubMed: 27137723
DOI: 10.1111/apt.13599 -
European Heart Journal Mar 2020Ventricular pressure-volume (PV) analysis is the reference method for the study of cardiac mechanics. Advances in calibration algorithms and measuring techniques brought... (Review)
Review
Ventricular pressure-volume (PV) analysis is the reference method for the study of cardiac mechanics. Advances in calibration algorithms and measuring techniques brought new perspectives for its application in different research and clinical settings. Simultaneous PV measurement in the heart chambers offers unique insights into mechanical cardiac efficiency. Beat to beat invasive PV monitoring can be instrumental in the understanding and management of heart failure, valvular heart disease, and mechanical cardiac support. This review focuses on intra cardiac left ventricular PV analysis principles, interpretation of signals, and potential clinical applications.
Topics: Cardiac Volume; Heart; Heart Failure; Heart Ventricles; Humans; Myocardial Contraction; Stroke Volume; Ventricular Function, Left; Ventricular Pressure
PubMed: 31435675
DOI: 10.1093/eurheartj/ehz552 -
RoFo : Fortschritte Auf Dem Gebiete Der... Sep 2019Rapid improvement of scanner and postprocessing technology as well as the introduction of minimally invasive procedures requiring preoperative imaging have led to the... (Review)
Review
BACKGROUND
Rapid improvement of scanner and postprocessing technology as well as the introduction of minimally invasive procedures requiring preoperative imaging have led to the broad utilization of cardiac computed tomography (CT) beyond coronary CT angiography (CTA).
METHOD
This review article presents an overview of recent literature on cardiac CT. The goal is to summarize the current guidelines on performing cardiac CT and to list established as well as emerging techniques with a special focus on extracoronary applications.
RESULTS AND CONCLUSION
Most recent guidelines for the appropriate use of cardiac CT include the evaluation of coronary artery disease, cardiac morphology, intra- and extracardiac structures, and functional and structural assessment of the myocardium under certain conditions. Besides coronary CTA, novel applications such as the calculation of a CT-derived fractional flow reserve (CT-FFR), assessment of myocardial function and perfusion imaging, as well as pre-interventional planning in valvular heart disease or prior pulmonary vein ablation in atrial fibrillation are becoming increasingly important. Especially these extracoronary applications are of growing interest in the field of cardiac CT and are expected to be gradually implemented in the daily clinical routine.
KEY POINTS
· Coronary artery imaging remains the main indication for cardiac CT. · Novel computational fluid dynamics allow the calculation of a CT-derived fractional flow reserve in patients with known or suspected coronary artery disease. · Cardiac CT delivers information on left ventricular volume as well as myocardial function and perfusion. · CT is the cardinal element for pre-interventional planning in transcatheter valve implantation and pulmonary vein isolation.
CITATION FORMAT
· Taron J, Foldyna B, Eslami P et al. Cardiac Computed Tomography - More Than Coronary Arteries? A Clinical Update. Fortschr Röntgenstr 2019; 191: 817 - 826.
Topics: Cardiac Volume; Coronary Angiography; Coronary Artery Disease; Coronary Circulation; Fractional Flow Reserve, Myocardial; Guideline Adherence; Heart Diseases; Humans; Tomography, X-Ray Computed; Transcatheter Aortic Valve Replacement; Ventricular Function, Left
PubMed: 31250415
DOI: 10.1055/a-0924-5883 -
Alimentary Pharmacology & Therapeutics Jun 2016
Topics: Cardiac Volume; Follow-Up Studies; Humans; Hypertension, Portal; Hypertension, Pulmonary; Portasystemic Shunt, Transjugular Intrahepatic
PubMed: 27137724
DOI: 10.1111/apt.13628 -
Journal of Cardiovascular Magnetic... Dec 2017Although atrial function has prognostic significance in many cardiovascular conditions, changes during exercise have not previously been assessed. The aim of this study...
BACKGROUND
Although atrial function has prognostic significance in many cardiovascular conditions, changes during exercise have not previously been assessed. The aim of this study was to evaluate left atrial (LA) and right atrial (RA) volume and function during incremental exercise, both in normal individuals, healthy athletes, and in patients with chronic thromboembolic pulmonary hypertension (CTEPH).
METHODS
Fifteen healthy non-athletes, 15 athletes and 15 CTEPH patients underwent multi-slice real-time cardiovascular magnetic resonance imaging at rest and during supine bicycle exercise with simultaneous invasive hemodynamic measurements.
RESULTS
At rest, athletes had larger indexed maximal RA and LA volumes (iRAVmax, iLAVmax) than CTEPH patients and non-athletes, the latter two groups having similar values. CTEPH patients had lower RA and LA emptying functions (EmF) at rest. During exercise, RA volumes (maximum and minimum) increased in CTEPH patients, whilst decreasing in athletes and non-athletes (P < 0.001). The exercise-induced change in iLAVmax was similar between groups, but iLAVmin did not decrease in CTEPH patients. Thus exercise-induced increases in RAEmF and LAEmF, as seen in normal physiology, were significantly impaired in CTEPH patients. At peak exercise, RA volumes (maximum and minimum) and EmF correlated strongly with RA pressure (R = 0.70; P = 0.005; R = 0.83; P < 0.001; R = -0.87; P < 0.001). On multivariate analysis, peak exercise RAEmF and iLAVmin were independent predictors of VOpeak in CTEPH patients and together explained 72% of the variance in VOpeak (ß =0.581 and ß = -0.515, respectively).
CONCLUSIONS
In normal physiology, RAEmF and LAEmF increase with exercise, whereas CTEPH patients have impaired LAEmF and RAEmF, which becomes more apparent during exercise. Therefore, the changes in atrial volumes and function during exercise enable a far better distinction between physiological and pathological atrial remodeling than resting measures of volumes which are prone to confounding factors (e.g. endurance training). Peak exercise RAEmF is a good marker of poor functional state in CTEPH patients.
Topics: Adult; Athletes; Atrial Function, Left; Cardiac Volume; Exercise; Exercise Test; Female; Heart Atria; Humans; Hypertension, Pulmonary; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Predictive Value of Tests; Prospective Studies
PubMed: 29254488
DOI: 10.1186/s12968-017-0416-9 -
Current Cardiology Reviews Aug 2011The goal of hemodynamic monitoring and management during major surgery is to guarantee adequate organ perfusion, a major prerequisite for adequate tissue oxygenation and... (Review)
Review
The goal of hemodynamic monitoring and management during major surgery is to guarantee adequate organ perfusion, a major prerequisite for adequate tissue oxygenation and thus, end-organ function. Further, hemodynamic monitoring should serve to prevent, detect, and to effectively guide treatment of potentially life-threatening hemodynamic events, such as severe hypovolemia due to hemorrhage, or cardiac failure. The ideal monitoring device does not exist, but some conditions must be met: it should be easy and operator-independently to use; it should provide adequate, reproducible information in real time. In this review we discuss in particular the role of intraoperative use of transesophageal echocardiography (TOE). Although TOE has gained special relevance in cardiac surgery, its role in major non cardiac surgery is still to be determined. We particularly focus on its ability to provide measurements of cardiac output (CO), and its role to guide fluid therapy. Within the last decade, concepts oriented on optimizing stroke volume and cardiac output mainly by fluid administration and guided by continuous monitoring of cardiac output or so called functional parameters of cardiac preload gained particular attention. Although they are potentially linked to an increased amount of fluid infusion, recent data give evidence that such pre-emptive concepts of hemodynamic optimization result in a decrease in morbidity and mortality. As TOE allows a real time direct visualization of cardiac structures, other potentially important advantages of its use also outside the cardiac surgery operation room can be postulated, namely the ability to evaluate the anatomical and functional integrity of the left and the right heart chambers. Finally, a practical approach to TOE monitoring is presented, based on a local experience.
Topics: Cardiac Output; Cardiac Surgical Procedures; Cardiac Volume; Echocardiography, Transesophageal; Fluid Therapy; Humans; Monitoring, Intraoperative; Ventricular Dysfunction, Left
PubMed: 22758616
DOI: 10.2174/157340311798220511 -
American Journal of Physiology. Heart... Feb 2012MRI has been proven to be an accurate method for noninvasive assessment of cardiac function. One of the current limitations of cardiac MRI is that it is time consuming....
Geometrical models for cardiac MRI in rodents: comparison of quantification of left ventricular volumes and function by various geometrical models with a full-volume MRI data set in rodents.
MRI has been proven to be an accurate method for noninvasive assessment of cardiac function. One of the current limitations of cardiac MRI is that it is time consuming. Therefore, various geometrical models are used, which can reduce scan and postprocessing time. It is unclear how appropriate their use is in rodents. Left ventricular (LV) volumes and ejection fraction (EF) were quantified based on 7.0 Tesla cine-MRI in 12 wild-type (WT) mice, 12 adipose triglyceride lipase knockout (ATGL(-/-)) mice (model of impaired cardiac function), and 11 rats in which we induced cardiac ischemia. The LV volumes and function were either assessed with parallel short-axis slices covering the full volume of the left ventricle (FV, gold standard) or with various geometrical models [modified Simpson rule (SR), biplane ellipsoid (BP), hemisphere cylinder (HC), single-plane ellipsoid (SP), and modified Teichholz Formula (TF)]. Reproducibility of the different models was tested and results were correlated with the gold standard (FV). All models and the FV data set provided reproducible results for the LV volumes and EF, with interclass correlation coefficients ≥0.87. All models significantly over- or underestimated EF, except for SR. Good correlation was found for all volumes and EF for the SR model compared with the FV data set (R(2) ranged between 0.59-0.95 for all parameters). The HC model and BP model also predicted EF well (R(2) ≥ 0.85), although proved to be less useful for quantitative analysis. The SP and TF models correlated poorly with the FV data set (R(2) ≥ 0.45 for EF and R(2) ≥ 0.29 for EF, respectively). For the reduction in acquisition and postprocessing time, only the SR model proved to be a valuable method for calculating LV volumes, stroke volume, and EF.
Topics: Animals; Cardiac Imaging Techniques; Cardiac Volume; Disease Models, Animal; Linear Models; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardial Infarction; Rats; Rats, Wistar; Reproducibility of Results; Stroke Volume; Ventricular Function, Left
PubMed: 22101529
DOI: 10.1152/ajpheart.00710.2011