The Ventricular-Arterial Coupling: From Basic Pathophysiology to Clinical Application in the Echocardiography Laboratory

Critical Care Ultrasound in Shock: A Comprehensive Review of Ultrasound Protocol for Hemodynamic Assessment in the Intensive Care Unit

Shock is a life-threatening condition that requires prompt recognition and treatment to prevent organ failure. In the intensive care unit, shock is a common presentation, and its management is challenging. Critical care ultrasound has emerged as a reliable and reproducible tool in diagnosing and classifying shock. This comprehensive review proposes an ultrasound-based protocol for the hemodynamic assessment of shock to guide its management in the ICU. The protocol classifies shock as either low or high cardiac index and differentiates obstructive, hypovolemic, cardiogenic, and distributive etiologies. In distributive shock, the protocol proposes a hemodynamic-based approach that considers the presence of dynamic obstruction, fluid responsiveness, fluid tolerance, and ventriculo-arterial coupling. The protocol gives value to quantitative measures based on critical care ultrasound to guide hemodynamic management. Using critical care ultrasound for a comprehensive hemodynamic assessment can help clinicians diagnose the etiology of shock and define the appropriate treatment while monitoring the response. The protocol's use in the ICU can facilitate prompt recognition, diagnosis, and management of shock, ultimately improving patient outcomes.

Computational modeling of heart failure in microgravity transitions

The space tourism industry is growing due to advances in rocket technology. Privatised space travel exposes non-professional astronauts with health profiles comprising underlying conditions to microgravity. Prior research has typically focused on the effects of microgravity on human physiology in healthy astronauts, and little is known how the effects of microgravity may play out in the pathophysiology of underlying medical conditions, such as heart failure. This study used an established, controlled lumped mathematical model of the cardiopulmonary system to simulate the effects of entry into microgravity in the setting of heart failure with both, reduced and preserved ejection fraction. We find that exposure to microgravity eventuates an increased cardiac output, and in patients with heart failure there is an unwanted increase in left atrial pressure, indicating an elevated risk for development of pulmonary oedema. This model gives insight into the risks of space flight for people with heart failure, and the impact this may have on mission success in space tourism.

Hemodynamic profile of cirrhotic patients with sepsis and septic shock: A propensity score matched case-control study

PURPOSE

Our understanding of hemodynamics in cirrhotic patients with sepsis remains limited. Our study aims to investigate differences in hemodynamic profiles using echocardiography between septic patients with and without cirrhosis.

MATERIALS AND METHODS

This is a single-center, retrospective study of septic patients with echocardiogram within 3 days of ICU admission. We compared baseline characteristics, echocardiographic markers of LV systolic function arterial load between patients with and without cirrhosis. A propensity score-matched case-control model was developed to describe the differences in those echocardiography derived parameters between the groups.

RESULTS

3151 patients with sepsis were included of which 422 (13%) had cirrhosis. In the propensity score matched group with 828 patients, cirrhotic patients had significantly higher left ventricular ejection fraction (64 vs.56%, p < 0.001) and stroke volume (72 vs.48 ml, p < 0.001) along with lower arterial elastance (Ea) (1.35 1vs.20.3, p < 0.001) and systemic vascular resistance (SVR) (851 vs.1209 dynes/s/m-5, p = 0.001). The left ventricular elastance (Ees) (2.83 vs 2.45, p = 0.002) was higher and ventricular-arterial coupling (Ea/Ees) (0.48 vs. 0.86, p < 0.001) lower in cirrhotic compared to non-cirrhotic.

CONCLUSIONS

Septic patients with cirrhosis had higher LVEF with lower Ea and SVR with higher Ees and significantly lower Ea/Ees suggesting vasodilation as the principal driver of the hyperdynamic profile in cirrhosis.

Comparison of Left Ventricular End-Diastolic Volume Approximated from Mean Blood Pressure and Stroke Volume and End-Diastolic Volume Calculated from Left Ventricular-Aortic Coupling

Objectives: The purpose of this study was to compare left ventricular end-diastolic volume (EDV), derived from left ventricular arterial coupling (Ees/Ea), and mean arterial blood pressure. Both of these methods of measuring EDV require some invasive procedure. However, the method of measuring EDV approximate is less invasive than the EDV coupling measuring method. This is because EDV approximate only requires arterial pressure waveform as an invasive procedure. Methods: This study included 14 patients with normal cardiac function who underwent general anesthesia. The point when blood pressure stabilized after the induction of anesthesia was taken as a baseline according to the study protocol. At the point when systolic arterial blood pressure fell 10% or more from the baseline blood pressure, 300 mL of colloid solution was administered over 15 min. EDV approximate and EDV coupling were calculated for each of the 14 patients at three points during the course of anesthetic. Each value was obtained by calculating a 5 min average. The timing of these three points was 5 min before, 5 min during, and 5 min after infusion loading. Results: The total number of comparable points was 42; 3 points were taken from each of the 14 participants. Both EDV approximate and EDV coupling increased through the infusion load testing. Scatter plots were prepared, and regression lines were calculated from the obtained values. A high correlation was shown between EDV approximate and EDV coupling (R2 = 0.96, p < 0.05). Conclusions: In patients with good cardiac function, EDV approximate can be substituted for EDV coupling, suggesting the possibility that EDV can be continuously and less invasively calculated under the situation of general anesthesia.

Development and Clinical Application of Left Ventricular-Arterial Coupling Non-Invasive Assessment Methods

The constant and dynamic interaction between ventricular function and arterial afterload, known as ventricular-arterial coupling, is key to understanding cardiovascular pathophysiology. Ventricular-arterial coupling has traditionally been assessed invasively as the ratio of effective arterial elastance over end-systolic elastance (Ea/Ees), calculated from information derived from pressure-volume loops. Over the past few decades, numerous invasive and non-invasive simplified methods to estimate the elastance ratio have been developed and applied in clinical investigation and practice. The echocardiographic assessment of left ventricular Ea/Ees, as proposed by Chen and colleagues, is the most widely used method, but novel echocardiographic approaches for ventricular-arterial evaluation such as left ventricle outflow acceleration, pulse-wave velocity, and the global longitudinal strain or global work index have arisen since the former was first published. Moreover, multimodal imaging or artificial intelligence also seems to be useful in this matter. This review depicts the progressive development of these methods along with their academic and clinical application. The left ventricular-arterial coupling assessment may help both identify patients at risk and tailor specific pharmacological or interventional treatments.

Left Ventricular-Arterial Coupling as an Independent Predictor of Adverse Events in Young Patients with ST Elevation Myocardial Infarction-A 3D Echocardiographic Study

Left ventricular-arterial coupling (VAC) is a key determinant of global cardiovascular performance, calculated as the ratio between arterial elastance (EA) and left ventricular end-systolic elastance (EES). Over the years, acute myocardial infarction (STEMI) has remained an important cause of morbidity and mortality worldwide. Although, until recently, it was considered a disease occurring mostly in older patients, its prevalence in the young population is continuously rising. In this study, we aimed to investigate the role of 3D VAC and its derived indices in predicting adverse outcomes in young patients with STEMI. We prospectively enrolled 84 young patients (18-51 years) with STEMI who underwent primary PCI and 28 healthy age and sex-matched controls. A 3D echocardiography was used for non-invasive measurements of end-systolic elastance (EES), arterial elastance (EA), and VAC (EA/EES). The occurrence of major adverse cardiac events (MACE) was assessed one year after the index STEMI. Out of 84 patients, 15.4% had adverse events at 12 months follow-up. Patients were divided into two groups according to the presence or absence of MACE. There were no significant differences in arterial elastance between the two groups. EA was higher in the MACE group but without statistical significance (2.65 vs. 2.33; p = 0.09). EES was significantly lower in the MACE group (1.25 ± 0.34 vs. 1.91 ± 0.56. p < 0.0001) and VAC was higher (2.2 ± 0.62 vs. 1.24 ± 0.29, p < 0.0001). ROC analysis showed that VAC has a better predictive value for MACE (AUC 0.927) compared with EA or EEA but also compared with a classical determinant of LV function (LVEF and LVGLS). A VAC value over 1.71 predicts unfavourable outcome with 83.3% sensitivity and 97.1% specificity. In both univariate and multivariate COX regression analysis, VAC remained an independent predictor for MACE and demonstrated incremental prognostic value over LVEF and LVGLS in the proposed statistical models. In conclusion, 3D VAC is an independent predictor of adverse events in young patients with STEMI at a 12 month follow-ups and could be used for a more accurate risk stratification in the acute phase.

Effects of Continuous Accelerated Pacing on Cardiac Structure and Function in Patients With Heart Failure With Preserved Ejection Fraction: Insights From the myPACE Randomized Clinical Trial

BACKGROUND

Heart failure with preserved ejection fraction ≥50% is prevalent with few evidence-based therapies. In a trial of patients with heart failure with preserved ejection fraction with specialized pacemakers, treatment with accelerated personalized pacing averaging 75 bpm (myPACE) markedly improved quality of life, NT-proBNP (N-terminal pro-brain natriuretic peptide), physical activity, and atrial fibrillation burden compared with the standard lower rate setting of 60 bpm (usual care).

METHODS AND RESULTS

In this exploratory study, provider-initiated echocardiographic studies obtained before and after the trial were assessed for changes in left ventricular (LV) structure and function among participants who continued their pacing assignment. The analytic approach aimed to detect differences in standard and advanced echocardiographic parameters within and between study arms. Of the 100 participants, 16 myPACE and 20 usual care arm had a qualifying set of echocardiograms performed a mean (SD) 3 (2.0) years apart. Despite similar baseline echocardiogram measures, sustained exposure to moderately accelerated pacing resulted in reduced septal wall thickness (in cm: myPACE 1.1 [0.2] versus usual care 1.2 [0.2], P=0.008) and lower LV mass to systolic volume ratio (in g/mL: myPACE 4.8 [1.9] versus usual care 6.8 [3.1], P=0.038) accompanied by a minor reduction in LV ejection fraction (in %: myPACE 55 [5] versus usual care 60 [5], P=0.015). These changes were paralleled by improvements in heart failure-related quality of life (myPACE Minnesota Living with Heart Failure Questionnaire improved by 16.1 [13.9] points, whereas usual care worsened by 6.9 [11.6] points, P<0.001). Markers of diastolic function and LV performance were not affected.

CONCLUSIONS

Exposure to continuous accelerated pacing in heart failure with preserved ejection fraction is associated with a reduced LV wall thickness and a small amount of LV dilation with small reduction in ejection fraction.

Mild hypothermia attenuates ischaemia/reperfusion injury: insights from serial non-invasive pressure-volume loops

AIMS

Mild hypothermia, 32-35°C, reduces infarct size in experimental studies, potentially mediating reperfusion injuries, but human trials have been ambiguous. To elucidate the cardioprotective mechanisms of mild hypothermia, we analysed cardiac performance in a porcine model of ischaemia/reperfusion, with serial cardiovascular magnetic resonance (CMR) imaging throughout 1 week using non-invasive pressure-volume (PV) loops.

METHODS AND RESULTS

Normothermia and Hypothermia group sessions (n = 7 + 7 pigs, non-random allocation) were imaged with Cardiovascular magnetic resonance (CMR) at baseline and subjected to 40 min of normothermic ischaemia by catheter intervention. Thereafter, the Hypothermia group was rapidly cooled (mean 34.5°C) for 5 min before reperfusion. Additional CMR sessions at 2 h, 24 h, and 7 days acquired ventricular volumes and ischaemic injuries (unblinded analysis). Stroke volume (SV: -24%; P = 0.029; Friedmans test) and ejection fraction (EF: -20%; P = 0.068) were notably reduced at 24 h in the Normothermia group compared with baseline. In contrast, the decreases were ameliorated in the Hypothermia group (SV: -6%; P = 0.77; EF: -6%; P = 0.13). Mean arterial pressure remained stable in Normothermic animals (-3%, P = 0.77) but dropped 2 h post-reperfusion in hypothermic animals (-18%, P = 0.007). Both groups experienced a decrease and partial recovery pattern for PV loop-derived variables over 1 week, but the adverse effects tended to attenuate in the Hypothermia group. Infarct sizes were 10 ± 8% in Hypothermic and 15 ± 8% in Normothermic animals (P = 0.32). Analysis of covariance at 24 h indicated that hypothermia has cardioprotective properties incremental to reducing infarct size, such as higher external power (P = 0.061) and lower arterial elastance (P = 0.015).

CONCLUSION

Using non-invasive PV loops by CMR, we observed that mild hypothermia at reperfusion alleviates the heart's work after ischaemia/reperfusion injuries during the first week and preserves short-term cardiac performance. This hypothesis-generating study suggests hypothermia to have cardioprotective properties, incremental to reducing infarct size. The primary cardioprotective mechanism was likely an afterload reduction acutely unloading the left ventricle.

The Relationship of Renal Augmented Velocity Index With Ventricular-Arterial Coupling in Comparison to Renal Resistive Index: Analysis by Means of Arterial and Ventricular Elastances in Hypertensive Patients

OBJECTIVE

It's a well-known scientific statement that the heart and kidney functions are frequently tied together and the impairment of one directly alters the other. However, there exist knowledge gaps about this intricate pathophysiologic link and the exact unifying mechanism is not established. Herein, we aimed to investigate the presence of cardiorenal interaction at subclinical level while the conventional cardiac and renal clinical parameters are not disrupted yet in patients with hypertension.

METHODS

We chose a novel renal Doppler ultrasonographic parameter-augmented velocity index (Avi)-and an echocardiographic measure-ventriculoarterial coupling-which is complex to analyze but increasingly used after its acceptance about being a key determinant of cardiovascular efficiency. We recruited 137 patients without a previous history of antihypertensive medication use (47.4% women; median age, 49 years). Renal Avi, renal resistive index (RI), arterial elastance (Ea ), ventricular elastance (Ees ) and Ea /Ees (ventriculoarterial coupling) parameters were all examined.

RESULTS

Renal Avi, Ea , and Ea /Ees values were higher in females. Correlation analysis revealed that renal Avi was correlated with many hemodynamic variables including Ea and Ea /Ees . On multiple linear regression analysis, Ea and Ea /Ees remained as significant independent predictors of renal Avi but not of renal RI after adjustments for co-variables (β = 0.488, P < .001 for Ea ; β = 0.380, P < .001 for Ea /Ees ).

CONCLUSIONS

In comparison to renal RI, we suggest that renal Avi is a more reliable and promising index that can even measure subclinical changes in the cardiorenal circulation which needs to be elucidated.

Cardiac Mechanical Performance Assessment at Different Levels of Exercise in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

There is a shortage of relevant studies interested in cardiac mechanical performance. Thus, it is clinically relevant to study the impact of cancer treatments on survivors' cardiac mechanical performance to improve our knowledge. The first objective of this study is to assess survivors' cardiac mechanical performance during a cardiopulmonary exercise test (CPET) using both ventricular-arterial coupling (VAC) and cardiac work efficiency (CWE) from cardiac magnetic resonance (CMR) acquisitions. The second objective is to assess the impact of doxorubicin and dexrazoxane (DEX) treatments.

METHODS

A total of 63 childhood acute lymphoblastic leukemia survivors underwent a CMR at rest on a 3T magnetic resonance imaging system, followed by a CPET on ergocycle. The CircAdapt model was used to study cardiac mechanical performance. At different levels of exercise, arterial elastance, end-systolic elastance, VAC, and CWE were estimated.

RESULTS

We observed significant differences between the different levels of exercise for both VAC ( P <0.0001) and CWE parameters ( P =0.001). No significant differences were reported between prognostic risk groups at rest and during the CPET. Nevertheless, we observed that survivors in the SR group had a VAC value slightly lower than heart rate (HR)+DEX and HR groups throughout the CPET. Moreover, survivors in the SR group had a CWE parameter slightly higher than HR+DEX and HR groups throughout the CPET.

CONCLUSIONS

This study reveals that the combination of CPET, CMR acquisitions and CircAdapt model was sensitive enough to observe slight changes in the assessment of VAC and CWE parameters. Our study contributes to improving survivors' follow-up and detection of cardiac problems induced by doxorubicin-related cardiotoxicity.

Ventriculo-arterial (un)coupling in septic shock: Impact of current and upcoming hemodynamic drugs

Sepsis is an archetype of distributive shock and combines different levels of alterations in preload, afterload, and often cardiac contractility. The use of hemodynamic drugs has evolved over the past few years, along with the invasive and non-invasive tools used to measure these components in real time. However, none of them is impeccable, which is why the mortality of septic shock remains too high. The concept of ventriculo-arterial coupling (VAC) allows for the integration of these three fundamental macroscopic hemodynamic components. In this mini review, we discuss the knowledge, tools, and limitations of VAC measurement, along with the evidence supporting ventriculo-arterial uncoupling in septic shock. Finally, the impact of recommended hemodynamic drugs and molecules on VAC is detailed.

Cirrhotic Cardiomyopathy Following Bile Duct Ligation in Rats-A Matter of Time?

Cirrhotic patients often suffer from cirrhotic cardiomyopathy (CCM). Previous animal models of CCM were inconsistent concerning the time and mechanism of injury; thus, the temporal dynamics and cardiac vulnerability were studied in more detail. Rats underwent bile duct ligation (BDL) and a second surgery 28 days later. Cardiac function was assessed by conductance catheter and echocardiography. Histology, gene expression, and serum parameters were analyzed. A chronotropic incompetence (Pd31 < 0.001) and impaired contractility at rest and a reduced contractile reserve (Pd31 = 0.03, Pdob-d31 < 0.001) were seen 31 days after BDL with increased creatine (Pd35, Pd42, and Pd56 < 0.05) and transaminases (Pd31 < 0.001). A total of 56 days after BDL, myocardial fibrosis was seen (Pd56 < 0.001) accompanied by macrophage infiltration (CD68: Pgroup < 0.001) and systemic inflammation (TNFα: Pgroup < 0.001, white blood cell count: Pgroup < 0.001). Myocardial expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) was increased after 31 (Pd31 < 0.001) and decreased after 42 (Pd42 < 0.001) and 56 days (Pd56 < 0.001). Caspase-3 expression was increased 31 and 56 days after BDL (Pd31 = 0.005; Pd56 = 0.005). Structural changes in the myocardium were seen after 8 weeks. After the second surgery (second hit), transient myocardial insufficiency with secondary organ dysfunction was seen, characterized by reduced contractility and contractile reserve.

Long-term prognostic impact of paravalvular leakage on coronary artery disease requires patient-specific quantification of hemodynamics

Transcatheter aortic valve replacement (TAVR) is a frequently used minimally invasive intervention for patient with aortic stenosis across a broad risk spectrum. While coronary artery disease (CAD) is present in approximately half of TAVR candidates, correlation of post-TAVR complications such as paravalvular leakage (PVL) or misalignment with CAD are not fully understood. For this purpose, we developed a multiscale computational framework based on a patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-structure interaction model to quantify metrics of global circulatory function, metrics of global cardiac function and local cardiac fluid dynamics in 6 patients. Based on our findings, PVL limits the benefits of TAVR and restricts coronary perfusion due to the lack of sufficient coronary blood flow during diastole phase (e.g., maximum coronary flow rate reduced by 21.73%, 21.43% and 21.43% in the left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)). Moreover, PVL may increase the LV load (e.g., LV load increased by 17.57% (N = 6)) and decrease the coronary wall shear stress (e.g., maximum wall shear stress reduced by 20.62%, 21.92%, 22.28% and 25.66% in the left main coronary artery (LMCA), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)), which could promote atherosclerosis development through loss of the physiological flow-oriented alignment of endothelial cells. This study demonstrated that a rigorously developed personalized image-based computational framework can provide vital insights into underlying mechanics of TAVR and CAD interactions and assist in treatment planning and patient risk stratification in patients.

Evaluation of patients with high burden of premature ventricular contractions by comprehensive transthoracic echocardiography

Background

The prevalence and prognosis of premature ventricular contractions (PVCs) among individuals without structural heart disease are uncertain. Standard transthoracic echocardiography is a common method in evaluation of underlying cardiovascular disease and is recommended as a diagnostic method in PVC patients. However, it is unclear whether comprehensive echocardiographic examination can identify pathological findings in PVC patients with a normal standard echocardiogram.

Method

We included forty consecutive patients with a high PVC burden (>10,000 PVCs/day) and normal findings at a standard echocardiogram and exercise test. All subjects were investigated by a comprehensive echocardiographic examination using parameters usually not included in a routine work-up. We compared the results with 22 age and sex-matched controls.

Results

In six additional parameters-global longitudinal strain, right ventricular strain, septal-lateral delay, ventricular-arterial coupling, integrated backscatter and left atrial activation time-a statistically significant difference was shown between PVC patients and controls. Among these parameters, global longitudinal strain had a high reliability between operators.

Conclusions

Despite normal findings at standard echocardiography, the PVC group showed signs of impaired heart function when more comprehensive echocardiography parameters were used.

Energy Drinks Decrease Left Ventricular Efficiency in Healthy Children and Teenagers: A Randomized Trial

Background: Minors are considered the main consumer group of energy drinks (EDs). The aim of this study was to investigate the acute effects of ED consumption on left ventricular (LV) hemodynamics and efficiency in healthy children and teenagers. Methods: This study was a randomized, single-blind, placebo-controlled, crossover clinical trial. Study participants consumed a weight-adjusted amount of an ED or a placebo on two consecutive days. LV hemodynamics and efficiency parameters were evaluated non-invasively by generating LV pressure−volume loops (PVLs) through simultaneous echocardiography and blood pressure measurement. Results: A total of 24 children and teenagers (14.90 ± 2.27 years, 13 male) were included in the present study. Conventional echocardiographic parameters of LV function did not show significant differences between both beverage groups. The non-invasive generation of LV PVLs revealed a significantly lower cardiac efficiency 240 min after the ED consumption compared to the placebo intake (140.72 (133.21−149.73) mmHg vs. 135.60 (124.78−140.33) mmHg, p < 0.01). Conclusions: Acute ED consumption is associated with a significantly lower cardiac efficiency in healthy minors. The generation of non-invasive LV PVLs might be beneficial in the assessment of subtle changes in LV efficiency. Further studies need to investigate the influence of chronic ED consumption on LV function and morphology.

Why are bleeding trauma patients still dying? Towards a systems hypothesis of trauma

Over the years, many explanations have been put forward to explain early and late deaths following hemorrhagic trauma. Most include single-event, sequential contributions from sympathetic hyperactivity, endotheliopathy, trauma-induced coagulopathy (TIC), hyperinflammation, immune dysfunction, ATP deficit and multiple organ failure (MOF). We view early and late deaths as a systems failure, not as a series of manifestations that occur over time. The traditional approach appears to be a by-product of last century's highly reductionist, single-nodal thinking, which also extends to patient management, drug treatment and drug design. Current practices appear to focus more on alleviating symptoms rather than addressing the underlying problem. In this review, we discuss the importance of the system, and focus on the brain's "privilege" status to control secondary injury processes. Loss of status from blood brain barrier damage may be responsible for poor outcomes. We present a unified Systems Hypothesis Of Trauma (SHOT) which involves: 1) CNS-cardiovascular coupling, 2) Endothelial-glycocalyx health, and 3) Mitochondrial integrity. If central control of cardiovascular coupling is maintained, we hypothesize that the endothelium will be protected, mitochondrial energetics will be maintained, and immune dysregulation, inflammation, TIC and MOF will be minimized. Another overlooked contributor to early and late deaths following hemorrhagic trauma is from the trauma of emergent surgery itself. This adds further stress to central control of secondary injury processes. New point-of-care drug therapies are required to switch the body's genomic and proteomic programs from an injury phenotype to a survival phenotype. Currently, no drug therapy exists that targets the whole system following major trauma.

Immune dysfunction following severe trauma: A systems failure from the central nervous system to mitochondria

When a traumatic injury exceeds the body's internal tolerances, the innate immune and inflammatory systems are rapidly activated, and if not contained early, increase morbidity and mortality. Early deaths after hospital admission are mostly from central nervous system (CNS) trauma, hemorrhage and circulatory collapse (30%), and later deaths from hyperinflammation, immunosuppression, infection, sepsis, acute respiratory distress, and multiple organ failure (20%). The molecular drivers of secondary injury include damage associated molecular patterns (DAMPs), pathogen associated molecular patterns (PAMPs) and other immune-modifying agents that activate the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic stress response. Despite a number of drugs targeting specific anti-inflammatory and immune pathways showing promise in animal models, the majority have failed to translate. Reasons for failure include difficulty to replicate the heterogeneity of humans, poorly designed trials, inappropriate use of specific pathogen-free (SPF) animals, ignoring sex-specific differences, and the flawed practice of single-nodal targeting. Systems interconnectedness is a major overlooked factor. We argue that if the CNS is protected early after major trauma and control of cardiovascular function is maintained, the endothelial-glycocalyx will be protected, sufficient oxygen will be delivered, mitochondrial energetics will be maintained, inflammation will be resolved and immune dysfunction will be minimized. The current challenge is to develop new systems-based drugs that target the CNS coupling of whole-body function.

Current Understanding of Molecular Pathophysiology of Heart Failure With Preserved Ejection Fraction

Heart Failure (HF) is the most common cause of hospitalization in the Western societies. HF is a heterogeneous and complex syndrome that may result from any dysfunction of systolic or diastolic capacity. Abnormal diastolic left ventricular function with impaired relaxation and increased diastolic stiffness is characteristic of heart failure with preserved ejection fraction (HFpEF). HFpEF accounts for more than 50% of all cases of HF. The prevalence increases with age: from around 1% for those aged <55 years to >10% in those aged 70 years or over. Nearly 50% of HF patients have HFrEF and the other 50% have HFpEF/HFmrEF, mainly based on studies in hospitalized patients. The ESC Long-Term Registry, in the outpatient setting, reports that 60% have HFrEF, 24% have HFmrEF, and 16% have HFpEF. To some extent, more than 50% of HF patients are female. HFpEF is closely associated with co-morbidities, age, and gender. Epidemiological evidence suggests that HFpEF is highly represented in older obese women and proposed as 'obese female HFpEF phenotype'. While HFrEF phenotype is more a male phenotype. In addition, metabolic abnormalities and hemodynamic perturbations in obese HFpEF patients appear to have a greater impact in women then in men (Sorimachi et al., European J of Heart Fail, 2022, 22). To date, numerous clinical trials of HFpEF treatments have produced disappointing results. This outcome suggests that a "one size fits all" approach to HFpEF may be inappropriate and supports the use of tailored, personalized therapeutic strategies with specific treatments for distinct HFpEF phenotypes. The most important mediators of diastolic stiffness are the cardiomyocytes, endothelial cells, and extracellular matrix (ECM). The complex physiological signal transduction networks that respond to the dual challenges of inflammatory and oxidative stress are major factors that promote the development of HFpEF pathologies. These signalling networks contribute to the development of the diseases. Inhibition and/or attenuation of these signalling networks also delays the onset of disease. In this review, we discuss the molecular mechanisms associated with the physiological responses to inflammation and oxidative stress and emphasize the nature of the contribution of most important cells to the development of HFpEF via increased inflammation and oxidative stress.

Pleiotropic vasoprotective effects of high-dose atorvastatin therapy in the context of achieving the target low-density lipoprotein cholesterol in patients after myocardial infarction

Aim. To study the lipid-lowering and pleiotropic vasoprotective effects of atorvastatin depending on the achievement of the target low-density lipoprotein cholesterol (LDL-C) level in patients after ST-segment elevation myocardial infarction (STEMI) within 48-week follow-up period.

Material and methods. A total of 125 patients with STEMI, randomized to receive atorvastatin 40 or 80 mg per day for 48 weeks, were examined. On days 7-9, after 24, 48 weeks, we performed biochemical blood tests, echocardiography, as well as assessed the carotid arteries and endothelial function. The subjects were divided into the following groups: high-efficiency therapy (HET) — 41 patients who reached target LDL-C at control visits; moderate-efficiency therapy (MET) — 35 patients who achieved target LDL-C at one visit; low-efficiency therapy effective (LET) — 49 people who did not reach the target LDL-C. Differences were considered significant at p<0,05.

Results. A decrease in detection rate of an elevated brain natriuretic peptide was found in HET group from 41,5 to 17% (p<0,01) and in MET group from 48,6 to 23% (p<0,01), while no changes in the LET were revealed. The glomerular filtration rate in the LET group decreased by 8% (p<0,01). In the HET group, a decrease in arterial elastance by 9,4%, intima-media thickness by 9,9%, a decrease in the frequency of a negative response and an increase in a positive response (p<0,05) were revealed.

Conclusion. The results demonstrate the importance of achieving target LDL-C for the most favorable dynamics of brain natriuretic peptide, structural and functional characteristics of the arterial system.

Incremental prognostic value of arterial elastance in mild-to-moderate idiopathic pulmonary fibrosis

Previous reports suggested that poor pulmonary function was associated with increased arterial elastance (Ea) in patients with chronic obstructive pulmonary disease and systemic sclerosis. The mechanisms connecting pulmonary function and Ea have not yet been accurately studied in patients with idiopathic pulmonary fibrosis (IPF). The present study was designed to assess Ea in IPF patients without chronic severe pulmonary hypertension and to determine its prognostic role over a medium-term follow-up. This retrospective study included 60 consecutive patients with mild-to-moderate IPF (73.8 ± 6.6 years, 75% males) and 60 controls matched by age, sex and cardiovascular risk factors. All patients underwent physical examination, spirometry, blood tests, modified Haller index (MHI, chest transverse diameter over the distance between sternum and spine) assessment, conventional transthoracic echocardiography implemented with speckle tracking analysis of left atrial positive global strain (LA-GSA+ ) and finally carotid Doppler ultrasonography, at basal evaluation. The effective arterial elastance index (EaI) was calculated as the ratio of end-systolic pressure to stroke volume index. During follow-up period, we evaluated the composite endpoint of (1) pulmonary or cardiovascular hospitalizations; (2) all-cause mortality. At baseline, EaI was significantly higher in IPF patients than controls (4.1 ± 1.3 vs 3.5 ± 1.0 mmHg/ml/m2, p = 0.01). EaI was strongly correlated to the following variables: C-reactive protein (CRP) (r = 0.86), forced vital capacity (FVC) (r =  - 0.91), E/e' ratio (r = 0.91), LA-GSA+  (r =  - 0.92), common carotid artery-cross sectional area (CCA-CSA) (r = 0.89) and MHI (r = 0.86), in IPF patients. Mean follow-up time was 2.4 ± 1.3 years. During follow-up, 12 patients died and 17 were hospitalized due to major adverse clinical events. At univariate Cox analysis, CRP (HR 1.51, 95% CI 1.25-1.82), FVC (HR 0.88, 95% CI 0.85-0.91), LA-GSA+  (HR 0.85, 95% CI 0.77-0.94), CCA-CSA (HR 1.12, 95% CI 1.03-1.22) and EaI (HR 2.43, 95% CI 1.75-3.37) were significantly associated with outcome. At multivariate Cox analysis, only EaI (HR 1.60, 95% CI 1.03-2.50) retained statistical significance. An EaI ≥ 4 mmHg/ml/m2 showed 100% sensitivity and 99.4% specificity for predicting outcome (AUC = 0.98). In patients with mild-to-moderate IPF, an EaI ≥ 4 mmHg/ml/m2 is a negative prognostic factor over a medium-term follow-up.

Chest Shape Influences Ventricular-Arterial Coupling Parameters in Infants with Pectus Excavatum

Background

The present study was designed to investigate the possible influence of chest shape, noninvasively assessed by modified Haller index (MHI), on ventricular-arterial coupling (VAC) parameters in a population of term infants with pectus excavatum (PE).

Methods

Sixteen consecutive PE infants (MHI >2.5) and 44 infants with normal chest shape (MHI ≤2.5) were prospectively analyzed. All infants underwent evaluation by a neonatologist, transthoracic echocardiography, and MHI assessment (ratio of chest transverse diameter over the distance between sternum and spine) within 3 days of life. Arterial elastance index (EaI) was determined as end-systolic pressure (ESP)/stroke volume index, whereas end-systolic elastance index (EesI) was measured as ESP/left ventricular end-systolic volume index. Finally, VAC was derived by the Ea/Ees ratio.

Results

At 2.1 ± 1 days after birth, compared to controls (MHI = 2.01 ± 0.2), PE infants (MHI = 2.76 ± 0.2) were diagnosed with significantly smaller size of all cardiac chambers. Biventricular systolic function, left ventricular filling pressures, and pulmonary hemodynamics were similar in both the groups of infants. Both EaI (4.4 ± 1.0 mmHg/ml/m2 vs. 3.4 ± 0.6 mmHg/ml/m2, P < 0.001) and EesI (15.1 ± 3.0 mmHg/ml/m2 vs. 12.7 ± 2.5 mmHg/ml/m2, P = 0.003) were significantly increased in PE infants than controls. The resultant VAC (0.30 ± 0.10 vs. 0.30 ± 0.08, P > 0.99) was similar in both the groups of infants. Both EaI (r = 0.93) and EesI (r = 0.87) were linearly correlated with MHI in PE infants, but not in controls. On the other hand, no correlation was found between MHI and VAC in both the groups of infants.

Conclusions

Chest deformity strongly influences both Ea and Ees in PE infants, due to extrinsic cardiac compression, in the absence of any intrinsic cardiovascular dysfunction.

Cardiac and Vascular Remodeling After 6 Months of Therapy With Sacubitril/Valsartan: Mechanistic Insights From Advanced Echocardiographic Analysis

Background

Effects of Sacubitril/Valsartan (S/V) on left ventricular (LV) mechanics and ventricular-arterial coupling in patients with heart failure with reduced ejection fraction (HFrEF) are not completely understood. The aim of this study was to evaluate both cardiac and vascular remodeling in a group of HFrEF patients undergoing S/V therapy.

Methods

Fifty HFrEF patients eligible to start a therapy with S/V were enrolled. Echocardiographic evaluation was performed at baseline and after 6 months of follow-up (FU). Beside standard evaluation, including global longitudinal strain (GLS), estimated hemodynamic forces (HDFs) and non-invasive pressure-volume curves (PV loop) were assessed using dedicated softwares. HDFs were evaluated over the entire cardiac cycle, in systole and diastole, both in apex to base (A-B) and latero-septal (L-S) directions. The distribution of LV HDFs was evaluated by L-S over A-B HDFs ratio (L-S/A-B HDFs ratio). Parameters derived from estimated PV loop curves were left ventricular end-systolic elastance (E_es), arterial elastance (E_a), and ventricular-arterial coupling (VAC).

Results

At 6 months of FU indexed left ventricular end-diastolic and end-systolic volumes decreased (EDVi: 101 ± 28 mL vs. 86 ± 30 mL, p < 0.001; ESVi: 72 ± 23 mL vs. 55 ± 24 mL, p < 0.001), ejection fraction and GLS significantly improved (EF: 29 ± 6% vs. 37 ± 7%, p < 0.001; GLS: −9 ± 3% vs. −13 ± 4%, p < 0.001). A reduction of E_a (2.11 ± 0.91 mmHg/mL vs. 1.72 ± 0.44 mmHg/mL, p = 0.008) and an improvement of E_es (1.01 ± 0.37 mmHg/mL vs. 1.35 ± 0.6 mmHg/mL, p < 0.001) and VAC (2.3 ± 1.1 vs. 1.5 ± 0.7, p < 0.001) were observed. Re-alignment of HDFs occurred, with a reduction of diastolic L-S/A-B HDFs ratio [23 (20–35)% vs. 20 (11–28) %, p < 0.001].

Conclusion

S/V therapy leads to a complex phenomenon of reverse remodeling involving increased myocardial contractility, HDFs distribution improvement, and afterload reduction.

Characteristics of circulatory failure after out-of-hospital cardiac arrest: a prospective cohort study

Background

Circulatory failure after out-of-hospital cardiac arrest (OHCA) as part of the postcardiac arrest syndrome (PCAS) is believed to be caused by an initial myocardial depression that later subsides into a superimposed vasodilatation. However, the relative contribution of myocardial dysfunction and systemic inflammation has not been established. Our objective was to describe the macrocirculatory and microcirculatory failure in PCAS in more detail.

Methods

We included 42 comatose patients after OHCA where circulatory variables were invasively monitored from admission until day 5. We measured the development in cardiac power output (CPO), stroke work (SW), aortic elastance, microcirculatory metabolism, inflammatory and cardiac biomarkers and need for vasoactive medications. We used survival analysis and Cox regression to assess time to norepinephrine discontinuation and negative fluid balance, stratified by inflammatory and cardiac biomarkers.

Results

CPO, SW and oxygen delivery increased during the first 48 hours. Although the estimated afterload fell, the blood pressure was kept above 65 mmHg with a diminishing need for norepinephrine, indicating a gradually re-established macrocirculatory homoeostasis. Time to norepinephrine discontinuation was longer for patients with higher pro-brain natriuretic peptide concentration (HR 0.45, 95% CI 0.21 to 0.96), while inflammatory biomarkers and other cardiac biomarkers did not predict the duration of vasoactive pressure support. Markers of microcirculatory distress, such as lactate and venous-to-arterial carbon dioxide difference, were normalised within 24 hours.

Conclusion

The circulatory failure was initially characterised by reduced CPO and SW, however, microcirculatory and macrocirculatory homoeostasis was restored within 48 hours. We found that biomarkers indicating acute heart failure, and not inflammation, predicted longer circulatory support with norepinephrine. Taken together, this indicates an early and resolving, rather than a late and emerging vasodilatation.

Trial registration

NCT02648061.

Is biventricular vascular coupling a better indicator of ventriculo-ventricular interaction in congenital heart disease?

BACKGROUND

Ventriculo-ventricular interactions are known to exist, though not well quantified. We hypothesised that the ventricular-vascular coupling ratio assessed by cardiovascular MRI would provide insight into this relationship. We also sought to compare MRI-derived ventricular-vascular coupling ratio to echocardiography and patient outcomes.

METHODS

Children with cardiac disease and biventricular physiology were included. Sanz's and Bullet methods were used to calculate ventricular-vascular coupling ratio by MRI and echocardiography, respectively. Subgroup analysis was performed for right and left heart diseases. Univariate and multivariate regressions were performed to determine associations with outcomes.

RESULTS

A total of 55 patients (age 14.3 ± 2.5 years) were included. Biventricular ventricular-vascular coupling ratio by MRI correlated with each other (r = 0.41; p = 0.003), with respect to ventricle's ejection fraction (r = -0.76 to -0.88; p < 0.001) and other ventricle's ejection fraction (r = -0.42 to -0.47; p < 0.01). However, biventricular ejection fraction had only weak correlation with each other (r = 0.31; p = 0.02). Echo underestimated ventricular-vascular coupling ratio for the left ventricle (p < 0.001) with modest correlation to MRI-derived ventricular-vascular coupling ratio (r = 0.43; p = 0.002). There seems to be a weak correlation between uncoupled right ventricular-vascular coupling ratio with the need for intervention and performance on exercise testing (r = 0.33; p = 0.02).

CONCLUSION

MRI-derived biventricular ventricular-vascular coupling ratio provides a better estimate of ventriculo-ventricular interaction in children and adolescents with CHD. These associations are stronger than traditional parameters and applicable to right and left heart conditions.

Clinical implication of intraoperative ventricular-arterial coupling in pediatric patients undergoing ventricular septal defects repair: A retrospective cohort study

BACKGROUND

Ventricular-arterial coupling is the ratio of arterial elastance to ventricular end-systolic elastance.

AIMS

The objective of this study was to determine the clinical implication of intraoperative ventricular-arterial coupling derived from the pressure-area relationship using transesophageal echocardiography.

METHODS

This retrospective study reviewed the medical records of 72 pediatric patients with ventricular septal defects who underwent corrective surgery with cardiopulmonary bypass. The single-beat modified method was used to assess ventricular-arterial coupling. Logistic regression analyses were performed to determine the correlation between ventricular-arterial coupling and early postoperative outcomes, including the maximum vasoactive-inotropic score, length of mechanical ventilation, and length of hospital stay.

RESULTS

Ventricular-arterial coupling after cardiopulmonary bypass significantly increased (from 1.0 ± 0.4 to 1.4 ± 0.8, p < .001), indicating a disproportionate increase in the arterial elastance index (from 11.5 ± 5.1 to 19.8 ± 7.5 mmHg/cm² /m² , p < .001) compared with the ventricular end-systolic elastance index (from 13.0 ± 6.9 to 16.9 ± 9.0 mmHg/cm² /m² , p < .001). Logistic regression analyses revealed that high postoperative ventricular-arterial coupling was independently associated with higher postoperative maximum vasoactive-inotropic score (>10; odds ratio [OR], 8.04; 95% confidence interval [CI], 1.38-46.85, p = .020), longer postoperative mechanical ventilation (>15 h; OR: 11.00; 95% CI: 1.26-96.45, p = .030), and longer postoperative hospital stay (>7 days; OR: 2.98; 95% CI: 1.04-8.58, p = .043).

CONCLUSIONS

Ventricular-arterial coupling can be easily obtained from the intraoperative transesophageal echocardiography in pediatric patients undergoing ventricular septal defects repair. High postoperative ventricular-arterial coupling is strongly associated with worse early postoperative outcomes. Ventricular-arterial coupling shows promise as an intraoperative analysis tool that can provide insight into the impact of interventions on cardiovascular performance and identify potential targets for treatment in this population.

High-Intensity Interval Training for Heart Failure Patients With Preserved Ejection Fraction (HIT-HF)-Rational and Design of a Prospective, Randomized, Controlled Trial

Background: The pathophysiology of HF with preserved ejection fraction (HFpEF) has not yet been fully understood and HFpEF is often misdiagnosed. Remodeling and fibrosis stimulated by inflammation appear to be main factors for the progression of HFpEF. In contrast to patients with HF with reduced ejection fraction, medical treatment in HFpEF is limited to relieving HF symptoms. Since mortality in HFpEF patients remains unacceptably high with a 5-year survival rate of only 30%, new treatment strategies are urgently needed. Exercise seems to be a valid option. However, the optimal training regime still has to be elucidated. Therefore, the aim of the study is to investigate the effects of a high-intensity interval (HIT) training vs. a moderate continuous training (MCT) on exercise capacity and disease-specific mechanisms in a cohort of patients with HFpEF. Methods: The proposed study will be a prospective, randomized controlled trial in a primary care setting including 86 patients with stable HFpEF. Patients will undergo measurements of exercise capacity, disease-specific blood biomarkers, cardiac and arterial vessel structure and function, total hemoglobin mass, metabolic requirements, habitual physical activity, and quality of life (QoL) at baseline and follow-up. After the baseline visit, patients will be randomized to the intervention or control group. The intervention group (n = 43) will attend a supervised 12-week HIT on a bicycle ergometer combined with strength training. The control group (n = 43) will receive an isocaloric supervised MCT combined with strength training. After 12 weeks, study measurements will be repeated in all patients to quantify the effects of the intervention. In addition, telephone interviews will be performed at 6 months, 1, 2, and 3 years after the last visit to assess clinical outcomes and QoL. Discussion: We anticipate clinically significant changes in exercise capacity, expressed as VO_2peak, as well as in disease-specific mechanisms following HIT compared to MCT. Moreover, the study is expected to add important knowledge on the pathophysiology of HFpEF and the clinical benefits of a training intervention as a novel treatment strategy in HFpEF patients, which may help to improve both QoL and functional status in affected patients. Trial registration: ClinicalTrials.gov, identifier: NCT03184311, Registered 9 June 2017.

Males with abdominal aortic aneurysm have reduced left ventricular systolic and diastolic function

BACKGROUND

Abdominal aortic aneurysm (AAA) increases the risk of chronic heart failure and other major cardiovascular events. Knowledge about left ventricular function in patients with AAA is lacking. This echocardiographic study aimed to investigate whether AAA is associated with left ventricular systolic and diastolic dysfunction.

METHODS

Echocardiography was performed in 307 males (199 AAA and 108 controls) recruited from a regional ultrasound surveillance programme of known AAA, or from an ongoing ultrasound screening programme, during 2011-2016.

RESULTS

Subjects with AAA had thicker septal and posterior walls and a reduced left ventricular function compared to controls. Left ventricular ejection fraction (AAA 55 ± 8%, controls 57 ± 7%) and global longitudinal strain (AAA 19 ± 3%, controls 20 ± 3%) were lower in the group with AAA (both p < 0·05). Moreover, decreased mitral annular plane systolic excursion (12 ± 2 mm versus 13 ± 2 mm) and higher E/e' (13 ± 5 versus 11 ± 4) were observed in subjects with AAA (both p < 0·05). The aortic sinus (38 ± 4 mm versus 35 ± 2 mm) and ascending aorta (36 ± 4 mm versus 34 ± 5 mm) were also wider in the AAA group compared to controls (both p < 0·01).

CONCLUSION

AAAs are associated with reduced left ventricular systolic and diastolic function in males. The larger diameter of the aortic sinus and ascending aorta among AAA patients suggests that AAA is a general aortic disease.

The effect of left ventricular contractility on arterial hemodynamics: A model-based investigation

Ventricular-arterial coupling is a major determinant of cardiovascular performance, however, there are still inherent difficulties in distinguishing ventricular from vascular effects on arterial pulse phenotypes. In the present study, we employed an extensive mathematical model of the cardiovascular system to investigate how sole changes in cardiac contractility might affect hemodynamics. We simulated two physiologically relevant cases of high and low contractility by altering the end-systolic elastance, E_es, (3 versus 1 mmHg/mL) under constant cardiac output and afterload, and subsequently performed pulse wave analysis and wave separation. The aortic forward pressure wave component was steeper for high E_es, which led to the change of the total pressure waveform from the characteristic Type A phenotype to Type C, and the decrease in augmentation index, AIx (-2.4% versus +18.1%). Additionally, the increase in E_es caused the pulse pressure amplification from the aorta to the radial artery to rise drastically (1.86 versus 1.39). Our results show that an increase in cardiac contractility alone, with no concomitant change in arterial properties, alters the shape of the forward pressure wave, which, consequently, changes central and peripheral pulse phenotypes. Indices based on the pressure waveform, like AIx, cannot be assumed to reflect only arterial properties.

Ventricular-arterial coupling: definition, pathophysiology and therapeutic targets in cardiovascular disease

INTRODUCTION

The heart and arterial system are equally affected by arteriosclerosis/atherosclerosis. There is a constant interaction between the left ventricular (LV) function and the arterial system, termed ventricular-arterial coupling (VAC), which reflects the global cardiovascular efficiency. VAC is traditionally assessed by echocardiography as the ratio of effective arterial elastance (E_a) over end-systolic elastance (E_es) (E_a/E_es). However, the concept of VAC is evolving and new methods have been proposed such as the ratio of pulse wave velocity (PWV) to global longitudinal strain (GLS) and myocardial work index.

AREA COVERED

This clinical review presents the hemodynamic background of VAC, its clinical implications and the impact of therapeutic interventions to normalize VAC. The review also summarizes the detrimental effects of cardio-metabolic risk factors on the aorta and LV, and provides an update on arterial load and its impact on LV function. The narrative review is based upon a systemic search of the bibliographic database PubMed for publications on VAC.

EXPERT OPINION

Newer methods such as PWV/GLS-ratio may be a superior marker of VAC than the traditional echocardiographic E_a/E_es in predicting target organ damage and its association with clinical outcomes. Novel anti-diabetic drugs and optimal antihypertensive treatment may normalize VAC in high-risk patients.

Effects of Choice of Medical Imaging Modalities on a Non-invasive Diagnostic and Monitoring Computational Framework for Patients With Complex Valvular, Vascular, and Ventricular Diseases Who Undergo Transcatheter Aortic Valve Replacement

Due to the high individual differences in the anatomy and pathophysiology of patients, planning individualized treatment requires patient-specific diagnosis. Indeed, hemodynamic quantification can be immensely valuable for accurate diagnosis, however, we still lack precise diagnostic methods for numerous cardiovascular diseases including complex (and mixed) valvular, vascular, and ventricular interactions (C3VI) which is a complicated situation made even more challenging in the face of other cardiovascular pathologies. Transcatheter aortic valve replacement (TAVR) is a new less invasive intervention and is a growing alternative for patients with aortic stenosis. In a recent paper, we developed a non-invasive and Doppler-based diagnostic and monitoring computational mechanics framework for C3VI, called C3VI-DE that uses input parameters measured reliably using Doppler echocardiography. In the present work, we have developed another computational-mechanics framework for C3VI (called C3VI-CT). C3VI-CT uses the same lumped-parameter model core as C3VI-DE but its input parameters are measured using computed tomography and a sphygmomanometer. Both frameworks can quantify: (1) global hemodynamics (metrics of cardiac function); (2) local hemodynamics (metrics of circulatory function). We compared accuracy of the results obtained using C3VI-DE and C3VI-CT against catheterization data (gold standard) using a C3VI dataset (N = 49) for patients with C3VI who undergo TAVR in both pre and post-TAVR with a high variability. Because of the dataset variability and the broad range of diseases that it covers, it enables determining which framework can yield the most accurate results. In contrast with C3VI-CT, C3VI-DE tracks both the cardiac and vascular status and is in great agreement with cardiac catheter data.

Influence of chest conformation on ventricular-arterial coupling during normal pregnancy

PURPOSE

There is still controversy regarding the changes of ventricular-arterial coupling (VAC) during normal pregnancy. The possible influence of chest shape on VAC during normal pregnancy has never been investigated.

METHODS

Between October 2019 and June 2020, 59 healthy pregnant women (33.7 ± 4.4 years/old) were consecutively included. They underwent obstetric visit, modified Haller index (MHI) assessment, and complete echocardiographic evaluation with blood pressure measurement to assess arterial elastance (Ea), end-systolic elastance (Ees), and Ea/Ees as an index of VAC, at 12-14 weeks and 36-38 weeks gestation, then 6-9 weeks after delivery.

RESULTS

VAC progressively increased from the first to the third trimester of pregnancy, then decreased in the postpartum (P < 0.0001) in the whole study population. Women with concave-shaped chest wall (MHI >2.5, n = 31) but not women with normal chest shape (MHI ≤2.5, n = 28) showed a progressive increase in VAC during normal pregnancy. Women with MHI >2.5 showed a significantly less pronounced increase in stroke volume index (SVi) from the first to the third trimester of pregnancy. There was a strong linear correlation between third trimester MHI and VAC (r = 0.93).

CONCLUSIONS

Anatomical and/or extrinsic mechanical factors rather than impaired arterial elastance or reduced left ventricular contractility may contribute to changes in VAC during normal pregnancy in women with concave-shaped chest wall.

Thoracic Aortic Calcification and Pre-Clinical Hypertension by New 2017 ACC/AHA Hypertension Guidelines

The recently revised 2017 American College of Cardiology/American Heart Association (ACC/AHA) hypertension (HTN) guidelines employ a lower blood pressure threshold to define HTN, aiming for earlier prevention of HTN-related cardiovascular diseases (CVD). Thoracic aortic calcification (TAC), a new surrogate marker of aging and aortic medial layer degeneration, and different stages of HTN, according to the 2017 ACC/AHA HTN guidelines, remain unknown. We classified 3022 consecutive asymptomatic individuals enrolled into four HTN categories using the revised 2017 ACC/AHA guidelines: normal blood pressure (NBP), elevated blood pressure (EBP), and stage 1 (S1) and stage 2 (S2) HTN. The coronary artery calcification score and TAC metrics (total Agaston TAC score, total plaque volume (mm³), and mean density (Hounsfield units, HU)) were measured using multi-detector computed tomography. Compared to NBP, a graded and significant increase in the TAC metrics was observed starting from EBP and S1 and S2 HTN, using the new 2017 ACC/AHA guidelines (NBP as reference; all trends: p < 0.001). These differences remained consistent after being fully adjusted. Older age (>50 years), S1 and S2 HTN, prevalent diabetes, and chronic kidney disease (<60 mL/min/1.73 m²) are all independently contributing factors to higher TAC risk using multivariate stepwise logistic regressions (all p ≤ 0.001). The optimal cutoff values of systolic blood pressure, diastolic blood pressure, and pulse pressure were 121, 74, and 45 mmHg, respectively, for the presence of TAC after excluding subjects with known CVD and ongoing HTN medication treatment. Our data showed that the presence of TAC starts at a stage of elevated blood pressure not categorized as HTN from the updated 2017 ACC/AHA hypertension guidelines.

Early Identification of Patients at Risk for Incident Heart Failure With Preserved Ejection Fraction: Novel Approach to Echocardiographic Trends

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) continues to increase in prevalence with a 50% mortality rate within 3 years of diagnosis, but lacking effective evidence-based therapies. Specific echocardiographic markers are not typically used to trigger alarm before acute HFpEF decompensation. The goal of this study was to retrospectively track changes in echocardiographic markers leading to the time of incident HFpEF hospitalization.

METHODS AND RESULTS

In a single-center, retrospective analysis, patients with HFpEF admitted between 2007 and 2014 were identified using the International Classification of Diseases, 9th Revision with search refined using the European Society of Cardiology HFpEF guidelines. Using linear mixed effects models, changes in echocardiographic markers preceding acute HF decompensation owing to incident HFpEF were analyzed. We report on an incident HFpEF cohort of 242 patients, extending 18 years retrospectively, and including 675 echocardiograms analyzed from the overall sample at 14 distinct time intervals before acute decompensation. The regression models demonstrated 3 echocardiographic markers with statistically significant increases across multiple time intervals including, arterial elastance (P = .006), right atrial pressure estimate (P < .001), and right ventricular systolic pressure (P = .006). Other echocardiographic markers had individual time intervals with significant increases before acute decompensation, including (a) left atrial diameter, 8 to 10 years before HFpEF diagnosis, (b) left ventricular filling pressure 2 to 6 years before HFpEF diagnosis, (c) ventricular elastance 3 to 6 months before HFpEF diagnosis, and (d) ventricular elastance/arterial elastance as early as 10 to 20 years and as late as 3 to 6 months before HFpEF diagnosis. Furthermore, African Americans presented with incident HFpEF at an average younger age than White patients (65.6 ± 15.2 years vs. 76.7 years ± 11.7, P < .001).

CONCLUSIONS

Noninvasive echocardiographic markers associated with incident HFpEF diagnosis showed long, mid, and acute range, significant changes as far back as 10 to 20 years and as close as 3 to 6 months before acute HFpEF decompensation. Including a diverse study cohort is critical to understanding the phenotypic differences of HFpEF. This hypothesis-generating study identified a novel approach to identifying trends in echocardiographic markers that may be used as a signal of impending incident HFpEF.

Comparative Trial of the Effects of Left Ventricular and Biventricular Pacing on Indices of Cardiac Function and Clinical Course of Patients With Heart Failure: Rationale and Design of the READAPT Randomized Trial

Nonresponse to cardiac resynchronization therapy (CRT) has been related with right ventricular dysfunction. Ventriculoarterial coupling (VAC) assesses energy efficiency of the failing heart and stroke work maximization for a given contractility, for both systemic and pulmonary circulations. Preferential left ventricular pacing (pLVP) can overcome iatrogenic right ventricular dysfunction by achieving left ventricle resynchronization and by allowing for intrinsic activation of the right side, with ramifications extending beyond cardiac output and atrial fibrillation occurrence. In the present article, we detail the design of a single-center randomized clinical trial to evaluate the effects of a pLVP algorithm. More specifically, following randomization of 220 CRT-eligible patients to standard biventricular pacing and pLVP, their clinical course will be followed for 12 months, through echocardiography to study indices of systolic and diastolic function of ventricles, left and right side VAC to evaluate efficiency, and cardiopulmonary exercise test to objectively document improvements in functional status, as well as a self-reported quality of life questionnaire. Device programming will be based on echocardiography-evaluated maximization of stroke volume and subsequent interventricular and atrioventricular delay adjustments delegated to the device. Findings of this trial may provide evidence for alternative programming of the devices, linking pLVP to improved clinical outcomes.

Incremental prognostic role of left atrial reservoir strain in asymptomatic patients with moderate aortic stenosis

Left atrial (LA) mechanics assessed by two-dimensional speckle tracking echocardiography (2D-STE) have not been extensively studied and clearly characterized in patients with moderate aortic stenosis (AS). Accordingly, we aimed to evaluate the usefulness of LA reservoir strain for risk stratification of asymptomatic patients with moderate AS. This retrospective study included all consecutive asymptomatic patients with moderate AS who underwent transthoracic echocardiography implemented with 2D-STE analysis of LA myocardial strain and strain rate indices at our Institution, between February 2011 and September 2019. During the follow-up period, we evaluated the occurrence of any of the following: (1) CV hospitalization; (2) The recourse to AS surgery; (3) Cardiac death or sudden death. A total of 186 patients (mean age 71.9 ± 12.7 years, 61.8% men) were included in the present study. During a mean follow-up of 2.3 ± 1.9 years, no patients died and 63 adverse CV events were recorded: 48 patients were hospitalized because of heart failure (28 patients), acute coronary syndrome (10 patients), arrhythmias (10 patients) and 15 patients underwent AS surgery. At the multivariate Cox regression analysis, type 2 diabetes mellitus (OR 1.87, 95%CI 1.05-3.34, p = 0.03), NT-proBNP (OR average 1.14, 95%CI 1.02-1.27, p = 0.02), average E/e' ratio (OR 1.07, 95%CI 1.01-1.15, p = 0.04) and most of all left atrial positive global strain (LA-GSA+) (OR 0.85, 95%CI 0.81-0.90, p < 0.0001) were independently associated with the outcome. LA-GSA+ (optimal cut-off ≤ 19%, AUC = 0.94, 87% sensitivity, 99% specificity, positive predictive value 99%, negative predictive value 88%) showed the highest diagnostic performance. An impaired LA reservoir strain can contribute to identify a subset of asymptomatic patients with moderate AS at higher risk, who may benefit from closer echocardiographic follow-up and/or early surgery.

Elevated peak systolic blood pressure in endurance-trained athletes: Physiology or pathology?

Blood pressure is a function of cardiac output and peripheral vascular resistance. During graded exercise testing (GXT), systolic blood pressure (SBP) is expected to increase gradually along with work rate, oxygen consumption, heart rate, and cardiac output. Individuals exposed to chronic endurance training attain a greater exercise SBP than in their untrained state and sedentary counterparts, but it is currently unknown what is considered a safe upper limit. This review discusses key studies examining blood pressure response in sedentary individuals and athletes. We highlight the physiological characteristics of highly fit individuals in terms of cardiovascular physiology and exercise blood pressure and review the state of the current literature regarding the safety of high SBP during exercise in this particular subgroup. Findings from this review indicate that a consensus on what is a normal SBP response to exercise in highly fit subjects and direct causation linking high GXT SBP to pathology is lacking. Consequently, applying GXT SBP guidelines developed for a "normal" population to endurance-trained individuals appears unsupported at this time. Lack of evidence for poor outcomes leads us to infer that elevated peak SBP in this subgroup could more likely reflect an adaptive response to training, rather than a pathological outcome. Future studies should track clinical outcomes of those achieving elevated SBP and develop athlete-specific guidelines.

Left ventricle end-systolic elastance, arterial-effective elastance, and ventricle-arterial coupling in Epilepsy

OBJECTIVE

Sudden unexpected death in epilepsy (SUDEP) is a tragic event. Cardiac models of sudden death state that, paradoxically, healthy individuals compose most of the victims of this event. Exploration of cardiac physiological variables related to outcome could help unveil risk markers for sudden death in epilepsy. We investigated left ventricle end-systolic elastance, arterial-effective elastance and ventricle-arterial coupling (VAC) in PWE compared with controls.

MATERIAL & METHODS

Adult patients with temporal lobe epilepsy without known cardiovascular diseases were submitted to treadmill test and transthoracic echocardiogram. Individuals without epilepsy matched by sex, age, and body mass index composed the control group. Cardiac risk factors, exercise performance, autonomic data from treadmill test, systolic and diastolic function, morphological cardiac data, and left ventricle pressure-volume loop were recorded.

RESULTS

Sixty subjects were consecutively enrolled (30 PWE and 30 controls). Epilepsy duration was 22.5 ± 10.7 years (age of onset 15.2 ± 10.1 years). Treadmill variables were significantly worse in TLE patients compared with controls. End-systolic elastance, arterial-effective elastance, and ventricle-arterial coupling were similar between groups. Female sex, percentage of maximal predicted heart rate achieved in exercise, exercise time, and epilepsy duration explained 28,4% of VAC in PWE in multiple stepwise linear regression (P = .018).

CONCLUSIONS

Some aspects of the cardiac pressure-volume curves, mainly linked to left ventricle systolic performance, contractile function and their interaction with afterload appears normal in young PWE and cannot explain their increase risk to adverse outcomes or lower physical fitness.

Early hemodynamic changes after transcatheter aortic valve implantation in patients with severe aortic stenosis measured by invasive pressure volume loop analysis

Replacement of a stenotic aortic valve reduces immediately the ventricular to aortic gradient and is expected to improve diastolic and systolic left ventricular function over the long term. However, the hemodynamic changes immediately after valve implantation are so far poorly understood. Within this pilot study, we performed an invasive pressure volume loop analysis to describe the early hemodynamic changes after transcatheter aortic valve implantation (TAVI) with self-expandable prostheses. Invasive left ventricular pressure volume loop analysis was performed in 8 patients with aortic stenosis (mean 81.3 years) prior and immediately after transfemoral TAVI with a self-expandable valve system (St. Jude Medical Portico Valve). Parameters for global hemodynamics, afterload, contractility and the interaction of the cardiovascular system were analyzed. Left ventricular ejection fraction, (53.9% vs. 44.8%, p = 0.018), preload recruitable stroke work (68.5 vs. 44.8 mmHg, p = 0.012) and end-systolic elastance (3.55 vs. 2.17, p = 0.036) both marker for myocardial contractility declined significantly compared to baseline. As sign of impaired diastolic function, TAU, a preload-independent measure of isovolumic relaxation (37.3 vs. 41.8 ms, p = 0.018) and end-diastolic pressure (13.1 vs. 16.4 mmHg, p = 0.015) raised after valve implantation. Contrarily, a smaller ratio of end-systolic to arterial elastance (ventricular-arterial coupling) indicates an improvement of global cardiovascular energy efficiency (1.40 vs. 0.97 p = 0.036). Arterial elastance had a strong correlation with the number of conducted rapid ventricular pacings (Pearson correlation coefficient, r = 0.772, p = 0.025). Invasive left ventricular pressure volume loop analysis revealed impaired systolic and diastolic function in the early phase after TAVI with self-expandable valve for the treatment of severe aortic stenosis. Contrarily, we found indications for early improvement of global cardiovascular energy efficiency.

Acute effects of transcatheter aortic valve replacement on the ventricular-aortic interaction

Transcatheter aortic valve replacement (TAVR) is linked with an immediate increase in aortic systolic blood pressure and maximal flow, as well as steeper aortic pressure and flow wave upstrokes. After TAVR, the forward wave pumped by the heart is enhanced. Although the arterial properties remain unchanged, the central augmentation index (AIx) is markedly decreased after TAVR. This challenges the interpretation of AIx as a solely vascular measure in patients with aortic valve stenosis.

Value of combined cardiopulmonary and echocardiography stress test to characterize the haemodynamic and metabolic responses of patients with heart failure and mid-range ejection fraction

AIMS

To characterize heart failure (HF) with mid-range ejection fraction (HFmrEF), combining cardiopulmonary exercise test, and exercise stress echocardiography.

METHODS AND RESULTS

We studied 169 consecutive subjects (age 62.3 ± 11 years; 74% male): 30 healthy controls, 45 patients with HF and preserved EF (HFpEF), 40 HFmrEF, and 54 with HF and reduced EF (HFrEF). Left ventricular (LV) stroke volume (SV), EF, elastance, global longitudinal strain, E/E', oxygen consumption (VO2), and arterial-venous oxygen content difference (AVO2diff) were measured in all exercise stages. HFmrEF revealed baseline features intermediate between HFrEF and HFpEF, except for B-type natriuretic peptide levels, which was similar to HFpEF and significantly lower than HFrEF. Peak VO2 was not significantly different between HF groups. HFrEF exhibited a significantly lower peak SV as compared to either HFpEF or HFmrEF (74.3 ± 21.8 mL vs. 88.0 ± 17.4 mL and 96.5 ± 25.1 mL; P < 0.01), whereas peak heart rate was not significantly different between HF groups. A significantly reduced AVO2diff at peak exercise was apparent in HFpEF and HFmrEF (15.2 ± 3.3 mL/dL and 13.3 ± 4.2 mL/dL) vs. HFrEF (17.±6.6 mL/dL; P < 0.01), whereas no significant difference was reported between HFpEF and HFmrEF. Multivariate analysis in the overall population and all groups revealed peak parameters as independent predictors of peak VO2 (R2 = 0.90, P < 0.0001); AVO2diff showed the largest standardized regression coefficient.

CONCLUSION

In HFpEF and HFmrEF, effort intolerance is predominantly due to peripheral factors (AVO2diff), whereas in HFrEF peak VO2 is restricted by low increases in SV. Individual therapy according to which component of VO2 is more impaired is advisable.

Cardiovascular Outcomes in Young Adulthood in a Population-Based Very Low Birth Weight Cohort

OBJECTIVES

To assess differences in left heart structure and function, and endothelial function in a national cohort of very low birth weight (VLBW) young adults and term-born controls.

STUDY DESIGN

The New Zealand VLBW study is a prospective, population-based, longitudinal cohort study which included all infants born <1500 g in 1986. The VLBW cohort (n = 229; 71% of survivors) and term-born controls (n = 100), were assessed at age 26-30 years. Measures of left heart structure and function were evaluated by echocardiography, vascular function was assessed using blood pressure, reactive hyperemia index, and arterioventricular coupling by calculating left ventricular (LV) and arterial elastance.

RESULTS

Compared with controls, those born VLBW had smaller LVs, even when indexed for body surface area (mean LV mass, 89.7 ± 19.3 g/m² vs 95.0 ± 22.3 g/m² [P = .03]; LV end-diastolic volume, 58.3 ± 10.9 mL/m² vs 62.4 ± 12.4 mL/m² [P = .002]; and LV end-systolic volume, 20.8 ± 4.9 mL/m² vs 22.6 ± 5.8 mL/m² [P = .004]). VLBW participants had lower stroke volume (median, 37.2 mL/m² [IQR, 33-42 mL/m²] vs median, 40.1 mL/m² [IQR, 34-45 mL/m²]; P = .0059) and cardiac output (mean, 4.8 ± 1.2 L/min vs 5.1 ± 1.4 L/min; P = .03), but there was no difference in ejection fraction. The VLBW group had higher LV elastance (3.37 ± 0.88 mm Hg/mL vs 2.86 ± 0.75 mm Hg/mL; P < .0001) and arterial elastance (1.84 ± 0.4 vs 1.6 ± 0.4; P < .0001) and lower reactive hyperemia index (0.605 ± 0.28 vs 0.688 ± 0.31; P = .041). These measures were influenced by birth weight and sex, but we found limited associations with other perinatal factors.

CONCLUSIONS

Being born preterm and VLBW is associated with differences in cardiovascular structure and function in adulthood. This population may be more vulnerable to cardiovascular pathology as they age.

TRIAL REGISTRATION

Australian Clinical Trials Registry ACTRN12612000995875.

Weight Gain, Hypertension, and the Emergence of a Maladaptive Cardiovascular Phenotype Among US Football Players

Importance

Former US football athletes are at increased risk of cardiovascular (CV) morbidity and mortality compared with the general population and other professional athletes. However, responsible maladaptive CV phenotypes have not been fully characterized.

Objective

To address the emergence and progression of multiple independent factors associated with CV risk across serial years of collegiate US football participation.

Design, Setting, and Participants

Collegiate US football athletes from 2 National Collegiate Athletic Association Division I programs were recruited as freshmen between June 2014 and June 2017 and analyzed at multiple points throughout 3 complete years of collegiate US football participation (until January 2019). Excluded athletes were those who did not complete any season of US football training because of injury, illness, or leaving the team. Factors associated with CV risk assessed clinically, by transthoracic echocardiography, and by vascular applanation tonometry were recorded.

Exposures

The exposure of interest was seasonal US football exposure, including training, competition, and the training environment.

Main Outcomes and Measures

Primary outcome measures were left ventricular mass index and geometry (cardiac structure), early diastolic myocardial relaxation velocity (E'; diastolic function), and pulse-wave velocity (arterial stiffness).

Results

Of 186 individuals recruited as freshmen, 126 athletes were included in analyzed data. Collegiate US football athletes (62 white individuals [49%]; 63 black individuals [50%]; 77 nonlinemen [61%]; 49 linemen [39%]; 126 male individuals [100%]) weighed a mean (SD) of 101.1 (21.0) kg, with a mean systolic blood pressure of 129.1 (11.6) mm Hg at baseline of the freshman season. Adjusting for race, height, and player position, there were significant increases in weight (mean [SE] Δ, 4.74 [0.6] kg; P < .001), systolic blood pressure (mean [SE] Δ, 11.6 [1.6] mm Hg; P < .001), and pulse-wave velocity (mean [SE] Δ, 0.24 [0.09] m/s; P = .007), and significant declines in E' (mean [SE] Δ, -1.7 [0.3] cm/s; P < .001) across 3 years of US football participation. Weight gain was associated with both arterial stiffening (increased pulse-wave velocity, β = 0.01 [SE, 0.004]; P = .003) and the development of concentric left ventricular hypertrophy (odds ratio, 1.09 [95% CI, 1.05-1.14]; P < .001); increased systolic blood pressure was also associated with arterial stiffening (β = 0.01 [SE, 0.003]; P = .007) and the development of concentric left ventricular hypertrophy (odds ratio, 1.04 [95% CI, 1.01-1.07]; P = .02).

Conclusions and Relevance

Collegiate US football athletes who gain weight and develop increased systolic blood pressure levels are at risk for the development of a pathologic CV phenotype characterized by concentric left ventricular hypertrophy, arterial stiffening, and reduced left ventricular diastolic function. Future work aimed at optimizing CV health in this population, who are young but uniquely at risk, is warranted.

Arterial-Ventricular Coupling Evaluation in Individuals with Stress-Evidenced Diastolic Dysfunction: A Pilot Study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020;2020:2598-2601. [PMID: 33018538 DOI: 10.1109/embc44109.2020.9176106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

INTRODUCTION

Arterial-ventricular coupling (AVC) has been recognized as a key determinant of global cardiovascular performance. Diastolic dysfunction (DD) occurs when inadequate filling of the ventricles is related to an abnormal elevation of intracardiac filling pressures. In some cases, DD is evidenced during cardiac stress, provoked by exercise.

OBJECTIVE

To evaluate AVC in individuals with stress evidenced DD, in relation to controls.

MATERIALS AND METHODS

Stress echocardiography was applied to assess cardiac function during exercise. Arterial-ventricular coupling was evaluated, based on the assessment of left ventricular and arterial elastances.

RESULTS

AVC showed a significant difference at peak exercise compared to controls, basically due to a loss of cardiac contractility.

CONCLUSION

The manifestation of AVC coupling imbalance could act as a complementary parameter to support the diagnosis of DD.

Differences in right ventricular-pulmonary vascular coupling and clinical indices between repaired standard tetralogy of Fallot and repaired tetralogy of Fallot with pulmonary atresia

PURPOSE

The purpose of this study was to compare ventricular vascular coupling ratio (VVCR) between patients with repaired standard tetralogy of Fallot (TOF) and those with repaired TOF-pulmonary atresia (TOF-PA) using cardiovascular magnetic resonance (CMR).

MATERIALS AND METHODS

Patients with repaired TOF aged>6 years were prospectively enrolled for same day CMR, echocardiography, and exercise stress test following a standardized protocol. Sanz's method was used to calculate VVCR as right ventricle (RV) end-systolic volume/pulmonary artery stroke volume. Regression analysis was used to examine associations with exercise test parameters, New York Heart Association (NYHA) class, RV size and biventricular systolic function.

RESULTS

A total of 248 subjects were included; of these 222 had repaired TOF (group I, 129 males; mean age, 15.9±4.7 [SD] years [range: 8-29 years]) and 26 had repaired TOF-PA (group II, 14 males; mean age, 17.0±6.3 [SD] years [range: 8-29 years]). Mean VVCR for all subjects was 1.54±0.64 [SD] (range: 0.43-3.80). Mean VVCR was significantly greater in the TOF-PA group (1.81±0.75 [SD]; range: 0.78-3.20) than in the standard TOF group (1.51±0.72 [SD]; range: 0.43-3.80) (P=0.03). VVCR was greater in the 68 NYHA class II subjects (1.79±0.66 [SD]; range: 0.75-3.26) compared to the 179 NYHA class I subjects (1.46±0.61 [SD]; range: 0.43-3.80) (P<0.001).

CONCLUSION

Non-invasive determination of VVCR using CMR is feasible in children and adolescents. VVCR showed association with NYHA class, and was worse in subjects with repaired TOF-PA compared to those with repaired standard TOF. VVCR shows promise as an indicator of pulmonary artery compliance and cardiovascular performance in this cohort.

Myocardial Contractility: Historical and Contemporary Considerations

The term myocardial contractility is thought to have originated more than 125 years ago and has remained and enigma ever since. Although the term is frequently used in textbooks, editorials and contemporary manuscripts its definition remains illusive often being conflated with cardiac performance or inotropy. The absence of a universally accepted definition has led to confusion, disagreement and misconceptions among physiologists, cardiologists and safety pharmacologists regarding its definition particularly in light of new discoveries regarding the load dependent kinetics of cardiac contraction and their translation to cardiac force-velocity and ventricular pressure-volume measurements. Importantly, the Starling interpretation of force development is length-dependent while contractility is length independent. Most historical definitions employ an operational approach and define cardiac contractility in terms of the hearts mechanical properties independent of loading conditions. Literally defined the term contract infers that something has become smaller, shrunk or shortened. The addition of the suffix “ility” implies the quality of this process. The discovery and clinical investigation of small molecules that bind to sarcomeric proteins independently altering force or velocity requires that a modern definition of the term myocardial contractility be developed if the term is to persist. This review reconsiders the historical and contemporary interpretations of the terms cardiac performance and inotropy and recommends a modern definition of myocardial contractility as the preload, afterload and length-independent intrinsic kinetically controlled, chemo-mechanical processes responsible for the development of force and velocity.

Left ventricular remodelling among Turner syndrome patients: insights from non-invasive 3D echocardiography-derived pressure-volume loop analysis

BACKGROUND

Turner syndrome (TS) is a X-chromosomal disease affecting one in 2500-3000 female newborns. TS individuals are at high cardiovascular risk and more likely to be overweight or obese. The aim of this study was to assess left ventricular performance in TS patients through three-dimensional speckle tracking echocardiography (3DSTE) and non-invasive left ventricular pressure-volume loop (PVL) analysis. Moreover, this study focused on the impact of excess weight on the left ventricular efficiency in TS patients.

METHODS

Thirty-six TS patients and 19 healthy age-matched controls were included in this study. 3DSTE and non-invasive left ventricular PVL analysis were performed and left ventricular efficiency parameters were calculated.

RESULTS

TS patients had significantly lower values than controls in longitudinal strain (- 16.67 ± 3.23% vs. - 18.47 ± 1.87%; p = 0.029), but significantly higher values for arterial elastance (BSA) (3.31, 1.87-5.88 mmHg/mL vs. 2.99, 2.31-4.61 mmHg/mL; p = 0.011) and cardiac work (BSA) (292,070 ± 71,348 mmHg*mL*HR vs. 248,595 ± 70,510 mmHg*mL*HR; p = 0.036). Compared with normal weight patients, overweight and obese TS subjects demonstrated worse left ventricular efficiency (175.08 ± 17.73 mmHg vs. 157.24 ± 26.75 mmHg; p = 0.037). Even after excluding TS patients with cardiovascular morbidity, arterial elastance (BSA) was compared to healthy peers, significantly increased in TS patients.

CONCLUSIONS

3DSTE and non-invasive left ventricular PVL analysis might be useful tools to detect early cardiac changes in TS. Arterial elastance seems to be significantly increased in TS patients, independent of cardiovascular morbidity. Compared with normal weight TS patients, overweight/obese TS patients displayed lower left ventricular efficiency.

Evaluation of ventricular-arterial coupling by impedance cardiography in healthy volunteers

BACKGROUND

The interplay between cardiac function and the arterial system is currently defined as ventricular-arterial coupling (VAC) and it is an expression of global cardiovascular efficiency. VAC involves a variety of complex interactions between the heart and the vasculature. A basic index of VAC is the ratio of effective arterial elastance (Ea)/ end-systolic elastance (Ees). While this is often done with echocardiography, obtaining Ea/Ees using impedance cardiography is feasible, although this possibility has not been explored so far.

OBJECTIVE

The aim of this study was to compare the Ea/Ees values obtained using echocardiography and impedance cardiography.

APPROACH

Two independent operators estimated Ea/Ees in 91 (41  ±  14 years old, women 51%) untreated apparently healthy individuals using (1) Doppler echocardiography with the single-beat method developed by Chen et al (2001 J. Am. Coll. Cardiol. 38 2028-34); and (2) data provided by impedance cardiography. The differences between Ea/Ees values were compared and correlation between both methods was estimated.

MAIN RESULTS

Although Ea and Ees values calculated by impedance cardiography were lower than those estimated by echocardiography (-0.201  ±  0.457 mmHg ml^-1 and  -0.193  ±  0.413 mmHg ml^-1), Ea/Ees ratio values were similar. Thus, there was no significant difference between the mean values of Ea/Ees estimated by impedance cardiography or echocardiography (Ea/Ees impedance cardiography  -  Ea/Ees echocardiography  =  -0.015  ±  0.096, p   =  0.150). Ea/Ees values calculated by both methods were highly correlated (r  =  0.85, p   <  0.001), as well as the pre-ejection and left ventricular ejection time (r  =  0.83 and r  =  0.91, respectively).

SIGNIFICANCE

In healthy individuals, estimation of Ea/Ees by impedance cardiography yielded similar values to those obtained using echocardiography.