3D Echocardiography to Evaluate Right Atrial Pressure in Acutely Decompensated Heart Failure

Positive correlation between echocardiographic tricuspid E peak velocity and central venous pressure in dogs: A preliminary study

In the absence of vascular obstruction, central venous pressure (CVP) is a hydrostatic pressure in the cranial and caudal vena cava, providing valuable information about cardiac function and intravascular volume status. It is also a component in evaluating volume resuscitation in patients with septic shock and monitoring patients with right heart disease, pericardial disease, or volume depletion. Central venous pressure is calculated in dogs by invasive central venous catheterization, which is considered high-risk and impractical in critically ill patients. This study aimed to investigate the feasibility of using echocardiographic tricuspid E/E' as a noninvasive method to estimate CVP in anesthetized healthy dogs under controlled hypovolemic conditions. Ten male mixed-breed dogs were included in the study after a thorough health assessment. For hypovolemia induction, blood withdrawal was performed, and echocardiographic factors of the tricuspid valve, including peak E and E' velocities, were measured during CVP reduction. Repeated measures analysis of variance and Bonferroni post hoc tests were employed to compare the average difference between measured echocardiographic indices and CVP values derived from catheterization and intermittent measurement methods. Spearman's ρ correlation coefficient was used to evaluate the correlation between echocardiographic indices and CVP. E peak velocity had a significant negative correlation with venous blood pressure phases (r = -0.44, P = .001), indicating a decrease in peak E velocity with progressive CVP reduction. However, tricuspid valve E' peak velocity and E/E' did not correlate with CVP, suggesting that these parameters are not reliable for CVP estimation in dogs.

Correlation between echocardiographic estimation of right atrial pressure and invasive measurement of central venous pressure in postoperative pediatric patients with congenital heart disease: a prospective observational study

BACKGROUND

Right atrial pressure plays a critical role as a hemodynamic parameter in diagnosing pulmonary hypertension and other cardiac diseases, as well as guiding the treatment and prognosis of various cardiac disorders. If there is no obstruction between the inferior or superior vena cava (SVC) as central veins and the right atrium, the pressures in these veins could be considered equal to the right atrial pressure. This study aimed to examine the correlation between echocardiographic methods for estimating right atrial pressure and invasive measurements of central venous pressure (CVPi) in infants and children with congenital heart disease during the 48 h after cardiac surgery and to establish regression equations for echocardiographic estimation of central venous pressure (CVPe).

RESULTS

We prospectively enrolled 43 infants and children, ranging in age from 6 months to 16 years, including 20 males and 23 females. We found a significant correlation between CVPi and the ratio of the maximal diameter of IVC to the maximal diameter of the descending aorta ratio (IVCmax/DAOmax) (r = 0.529, P < 0.001), SVCS/D velocity ratio (SVCS/D) (r = 0.462, P = 0.006), right atrial vertical diameter (RAVD) (r = 0.409, P = 0.01), area (r = 0.384, P = 0.014), and tricuspid valve A wave acceleration rate (TVAAR) (r = 0.315, P = 0.048). Multiple regression analysis yielded an equation for estimating central venous pressure using four parameters related to the IVC, SVC, tricuspid valve, and right atrium. The equation is as follows: estimated CVP = 4.36 + (2.35 × IVCmax/DAOmax) + (1.06 × SVCS/D) +  (0.059 × RAVD) + (0.001 × TVAAR). This equation is strongly correlated with CVPi (Pearson r = 0.698, P = 0.002).

CONCLUSIONS

The estimation of central venous pressure through a multi-parametric equation that included the ratio of the maximal diameter of the inferior vena cava to the maximal diameter of the descending aorta, the ratio of S to D velocity of the superior vena cava, the vertical diameter of the right atrium, and the acceleration rate of the A wave of the tricuspid valve demonstrated a robust correlation with invasively measured central venous pressure. To assess the accuracy of predicted pressures by this equation, further investigations are required to apply this innovative multi-parametric formula to a prospective population of pediatric patients with congenital heart disease.

Approach to Decompensated Right Heart Failure in the Acute Setting

Acute right heart failure (ARHF) arises when the right ventricle fails to pump blood efficiently to the pulmonary circulation. This inefficiency leads to a decreased blood supply to various organs. ARHF is a significant health concern, often leading to increased hospital admissions and being associated with a higher risk of mortality. This condition underscores the importance of effective cardiac care and timely intervention to manage its complications and improve patient outcomes. Diagnosing ARHF involves a comprehensive approach that includes a physical examination to evaluate the patient's fluid status and heart-lung function, blood tests to identify potential triggers and help forecast patient outcomes and various imaging techniques. These imaging techniques include electrocardiograms, point-of-care ultrasounds, computed tomography, cardiac magnetic resonance imaging, and other advanced monitoring methods. These diagnostic tools collectively aid in a detailed assessment of the patient's cardiac and pulmonary health, essential for effective management of ARHF. The management of ARHF focuses on addressing the underlying causes, regulating fluid balance, and enhancing cardiac function through pharmacological treatments or mechanical support aimed at boosting right heart performance. This management strategy includes the use of medications that modulate preload, afterload, and inotropy; vasopressors; anti-arrhythmic drugs; ensuring proper oxygenation and ventilation; and the utilization of heart and lung assist devices as a bridge to potential transplantation. This review article is dedicated to exploring the pathophysiology of ARHF, examining its associated morbidity and mortality, evaluating the various diagnostic tools available, and discussing the diverse treatment modalities. The article seeks to provide a comprehensive understanding of ARHF, its impact on health, and the current strategies for its management.

Estimating right atrial pressure using upright computed tomography in patients with heart failure

OBJECTIVES

Upright computed tomography (CT) can detect slight changes particularly in the superior vena cava (SVC) volume in healthy volunteers under the influence of gravity. This study aimed to evaluate whether upright CT-based measurements of the SVC area are useful for assessing mean right atrial pressure (mRAP) in patients with heart failure.

METHODS

We performed CT in both standing and supine positions to evaluate the SVC (directly below the junction of the bilateral brachiocephalic veins) and inferior vena cava (IVC; at the height of the diaphragm) areas and analyzed their relationship with mRAP, measured by right heart catheterization in 23 patients with heart failure.

RESULTS

The median age of enrolled patients was 60 (51-72) years, and 69.6% were male. The median mRAP was 3 (1-7) mmHg. The correlations between the standing position SVC and IVC areas and mRAP were stronger than those in the supine position (SVC, ρ = 0.68, p < 0.001 and ρ = 0.43, p = 0.040; IVC, ρ = 0.57, p = 0.005 and ρ = 0.46, p = 0.026; respectively). Furthermore, the SVC area in the standing position was most accurate in identifying patients with higher mRAP (> 5 mmHg) (SVC standing, area under the receiver operating characteristic curve [AUC] = 0.91, 95% confidence interval [CI], 0.77-1.00; SVC supine, AUC = 0.78, 95% CI, 0.59-0.98; IVC standing, AUC = 0.77, 95% CI, 0.55-0.98; IVC supine, AUC = 0.72, 95% CI, 0.49-0.94). The inter- and intraobserver agreements (evaluated by intraclass correlation coefficients) for all CT measurements were 0.962-0.991.

CONCLUSIONS

Upright CT-based measurement of the SVC area can be useful for non-invasive estimation of mRAP under the influence of gravity in patients with heart failure.

KEY POINTS

• This study showed that the superior vena cava (SVC) area in the standing position was most accurate in identifying patients with heart failure with higher mean right atrial pressure. • Upright computed tomography-based measurements of the SVC area can be a promising non-invasive method for estimating mean right atrial pressure under the influence of gravity in patients with heart failure. • Clinical management of patients with heart failure based on this non-invasive modality may lead to early assessment of conditional changes and reduced hospitalization for exacerbation of heart failure.

IVC measurement for the noninvasive evaluation of central venous pressure

Central venous pressure (CVP) is one of only a handful of variables that can be used to assess a patient's volume status to attempt to optimize stroke volume. The gold standard method for assessing CVP is though pulmonary artery catheterization, which is invasive and risks severe complications such as pneumothorax and cardiac conduction abnormalities. Current noninvasive methods for estimating CVP such as jugular venous pressure assessment are imperfect with wide inter-examiner variability. The inferior vena cava (IVC) is a highly compliant vessel that uniquely does not constrict in response to hypovolemia, making it an ideal, noninvasive surrogate for the estimation of CVP. A range of IVC indices including minimum and maximum IVC diameter and fraction of IVC collapse with inspiration (known as collapsibility index) have been studied with highly variable results that range from excellent to poor correlation between these values and CVP. Despite this inconsistency in findings, multiple schemes have been proposed to attempt to estimate CVP from IVC measurements, but when prospectively tested, none has been shown to be accurate. Since the most recent 2015 American Society of Echocardiography guidelines, multiple studies have identified unique ways of improving the accuracy of IVC measurement, which could translate into better CVP estimation. The goal of this review is to summarize the many, often conflicting studies that exist in this area, and provide recommendations for future studies based on our findings.

Clinical utility of superior vena cava flow velocity waveform measured from the subcostal window for estimating right atrial pressure1

BACKGROUND

Superior vena cava (SVC) flow velocity waveform from the supraclavicular window reflects the right atrial pressure (RAP) status. Recent guidelines have stated that the subcostal window is an alternative view for recording SVC flow, but the validity of this approach remains unclear. This study aimed to determine the usefulness of SVC flow evaluation from the subcostal window for estimating RAP.

METHODS

Differences in SVC flow characteristics between opposite approaches were examined in 38 healthy adults. In 115 patients with cardiovascular diseases who underwent cardiac catheterization and echocardiography within 48 h, the ratio of peak systolic to diastolic forward SVC flows was measured (SVC-S/D), and the diagnostic ability of SVC-S/D for elevated RAP was tested. A validation cohort was conducted to confirm the diagnostic ability of SVC-S/D in 48 patients who underwent both cardiac catheterization and echocardiography within 24 h. In 59 patients of derivation and validation cohorts, the relationship between SVC flow and RAP was compared between the opposite windows.

RESULTS

Both systolic and diastolic SVC flow velocities were higher in the subcostal than in the supraclavicular approach, and effect of position change on the subcostal SVC-S/D was smaller than that on the supraclavicular SVC-S/D in healthy adults. Measurement of SVC-S/D from the subcostal window was feasible in 98 patients (85%). RAP was inversely correlated with SVC-S/D (r=-0.50, P<.001), and was an independent determinant of SVC-S/D after the adjustment for right ventricular systolic function (β=-0.48, P<.001). A cutoff value of 1.9 for SVC-S/D showed 85% sensitivity and 74% specificity in identifying elevated RAP. Additionally, SVC-S/D showed an incremental diagnostic value combined with inferior vena cava size and collapsibility (P=.006). When the cutoff value, SVC-S/D<1.9, was applied to the validation cohort, it showed an acceptable accuracy of 72%, and an incremental diagnostic value combined with inferior vena cava parameters (P=.033). SVC-S/D from the subcostal window correlated better with RAP than that from the supraclavicular window (P<.001, Meng's test).

CONCLUSIONS

Measurement of SVC flow velocity from the subcostal window was feasible, and SVC-S/D from the subcostal window could be an additive parameter for estimating RAP.

Relationship between right atrial pressure and the Model for End-Stage Liver Disease (MELD) score in patients with advanced heart failure

Background

This study aims to investigate the association between right atrial pressure and the Model for End-Stage Liver Disease score and to evaluate the ability of this scoring system to accurately predict the value of right atrial pressure.

Methods

Between April 2016 and November 2018, a total of 137 patients (118 males, 19 females; median age: 49 years; range, 40 to 54 years) with advanced heart failure who were candidates for left ventricular assist device implantation or heart transplantation were retrospectively analyzed. We developed a formula calculated by using the biochemical and cardiac catheterization parameters of the patients.

Results

There was a strong correlation between the right atrial pressure and the scores (r=0.510, p<0.001). The estimated right atrial pressure was calculated as "2 + (0.92 x Model for End-Stage Liver Disease Score)" (unstandardized coefficient 0.920, t value 7.674, p<0.001). The Model for End-Stage Liver Disease score was found to be an independent predictor of high right atrial pressure (odds ratio=1.491, 95% confidence interval: 1.244-1.786, p<0.001). The calculated area under the curve was 0.789 (95% confidence interval: 0.710-0.867, p<0.001) and the cut-off value of the Model for End-Stage Liver Disease score in the prediction of high right atrial pressure was 10.5 with 75% sensitivity and 73% specificity.

Conclusion

We define a method to calculate right atrial pressure obtained by using the Model for End-Stage Liver Disease score without the need for cardiac catheterization during the hospitalization and follow-up period of patients with advanced heart failure.

Assessment of right atrial dyssynchrony by 2D speckle-tracking in healthy young men following high altitude exposure at 4100 m

Background

High altitude exposure induces overload of right-sided heart and may further predispose to supraventricular arrhythmia. It has been reported that atrial mechanical dyssynchrony is associated with atrial arrhythmia. Whether high altitude exposure causes higher right atrial (RA) dyssynchrony is still unknown. The aim of study was to investigate the effect of high altitude exposure on right atrial mechanical synchrony.

Methods

In this study, 98 healthy young men underwent clinical examination and echocardiography at sea level (400 m) and high altitude (4100 m) after an ascent within 7 days. RA dyssynchrony was defined as inhomogeneous timing to peak strain and strain rate using 2D speckle-tracking echocardiography.

Results

Following high altitude exposure, standard deviation of the time to peak strain (SD-TPS) [36.2 (24.5, 48.6) ms vs. 21.7 (12.9, 32.1) ms, p<0.001] and SD-TPS as percentage of R–R’ interval (4.6 ± 2.1% vs. 2.5 ± 1.8%, p<0.001) significantly increased. Additionally, subjects with higher SD-TPS (%) at high altitude presented decreased right ventricular global longitudinal strain and RA active emptying fraction, but increased RA minimal volume index, which were not observed in lower group. Multivariable analysis showed that mean pulmonary arterial pressure and tricuspid E/A were independently associated with SD-TPS (%) at high altitude.

Conclusion

Our data for the first time demonstrated that high altitude exposure causes RA dyssynchrony in healthy young men, which may be secondary to increased pulmonary arterial pressure. In addition, subjects with higher RA dyssynchrony presented worse RA contractile function and right ventricular performance.

Echocardiographic RV-E/e' for predicting right atrial pressure: a review

Right atrial pressure (RAP) is a key cardiac parameter of diagnostic and prognostic significance, yet current two-dimensional echocardiographic methods are inadequate for the accurate estimation of this haemodynamic marker. Right-heart trans-tricuspid Doppler and tissue Doppler echocardiographic techniques can be combined to calculate the right ventricular (RV) E/e′ ratio – a reflection of RV filling pressure which is a surrogate of RAP. A systematic search was undertaken which found seventeen articles that compared invasively measured RAP with RV-E/e′ estimated RAP. Results commonly concerned pulmonary hypertension or advanced heart failure/transplantation populations. Reported receiver operating characteristic analyses showed reasonable diagnostic ability of RV-E/e′ for estimating RAP in patients with coronary artery disease and RV systolic dysfunction. The diagnostic ability of RV-E/e′ was generally poor in studies of paediatrics, heart failure and mitral stenosis, whilst results were equivocal in other diseases. Bland–Altman analyses showed good accuracy but poor precision of RV-E/e′ for estimating RAP, but were limited by only being reported in seven out of seventeen articles. This suggests that RV-E/e′ may be useful at a population level but not at an individual level for clinical decision making. Very little evidence was found about how atrial fibrillation may affect the estimation of RAP from RV-E/e′, nor about the independent prognostic ability of RV-E/e′ . Recommended areas for future research concerning RV-E/e′ include; non-sinus rhythm, valvular heart disease, short and long term prognostic ability, and validation over a wide range of RAP.

Diagnostic utility of right atrial reservoir strain to identify elevated right atrial pressure in heart failure

BACKGROUND

Accurate non-invasive estimation of right atrial pressure (RAP) is essential to assess volume status and optimize therapy in heart failure (HF). This study aimed to evaluate the utility of right atrial reservoir strain (RASr) assessed by speckle-tracking echocardiography to identify elevated RAP in HF and compare diagnostic performance with estimated RAP employing inferior vena cava size and collapsibility (RAP_IVC), in addition to RA area.

METHOD

Association between RASr and invasive RAP (RAP_Invasive) was examined in 103 HF subjects that underwent standard echocardiography with speckle-tracking strain analysis directly followed by right heart catheterization. The discriminatory ability of RASr to identify RAP_Invasive > 7 mmHg was evaluated and compared with RAP_IVC and RA area.

RESULTS

RASr demonstrated association with RAP_Invasive (β = -0.41, p < 0.001) and was an independent predictor when adjusted for potential confounders (β = -0.25, p < 0.001). Further, RASr showcased strong discriminatory ability to identify subjects with RAP_Invasive > 7 mmHg (AUC = 0.78; 95% CI 0.68-0.87; p < 0.001). At a cut-off value of -15%, RASr displayed 78% sensitivity and 72% specificity to identify elevated RAP_Invasive. In comparison, RAP_IVC (AUC = 0.71; 95% CI 0.61-0.81; p < 0.001) demonstrated 89% sensitivity and 32% specificity with high false positive rate. RA area (AUC = 0.66; 95% CI 0.55-0.76, p = 0.005) displayed 64% sensitivity and 53% specificity.

CONCLUSIONS

RASr demonstrates good ability to identify elevated RAP and relatively stronger diagnostic performance when compared with conventional non-invasive measures. RASr may be useful as a novel noninvasive estimate of RAP in HF management.

Prediction of Prognostic Hemodynamic Indices in Pulmonary Hypertension Using Non-Invasive Parameters

Effective targeted therapy of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) requires regular risk stratification. Among many prognostic parameters, three hemodynamic indices: right atrial pressure, cardiac index, and mixed venous saturation are considered critically important for correct risk classification. All of them are measured invasively and require right heart catheterization (RHC). The study was aimed to verify assumption that a model based on non-invasive parameters is able to predict hemodynamic profile described by the mentioned invasive indices. A group of 330 patients with pulmonary hypertension was used for the selection of the best predictors from the set of 17 functional, biochemical, and echocardiographic parameters. Multivariable logistic regression models for the prediction of low-risk and high-risk profiles were created. The cut-off points were determined and subsequent validation of the models was conducted prospectively on another group of 136 patients. The ROC curve analysis showed the very good discrimination power of the models (AUC 0.80-0.99) in the prediction of the hemodynamic profile in the total validation group and subgroups: PAH and CTEPH. The models indicated the risk profiles with moderate sensitivity (57-60%) and high specificity (87-93%). The method enables estimation of the hemodynamic indices when RHC cannot be performed.

Diagnosis of Acute Heart Failure Using Inferior Vena Cava Ultrasound: Systematic Review and Meta-analysis

OBJECTIVES

The utility of bedside inferior vena cava (IVC) ultrasound (US) in the diagnosis of heart failure (HF) is unclear. The aim of this study was to determine whether IVC parameters in patients with acute heart failure (AHF) are statistically different from those without HF.

METHODS

The MEDLINE database of English-language publications from 1966 to August 2018 was searched. Retrospective and prospective studies that included either IVC expiratory diameter (IVC_exp ) or IVC collapsibility index (IVC-CI) values were collected in patients with and without HF. to determine whether there was a statistical difference in the IVC parameters between these groups.

RESULTS

A total of 27 articles with a total of 1472 patients with AHF were included. The standard mean differences for the IVC_exp and IVC-CI for the control group versus the AHF group were found to be statistically significant (P < .0001). The combined mean IVC_exp values were 15.11 mm (95% confidence interval [CI], 14.19-16.02 mm) for the control group and 20.26 mm (95% CI, 14.82-25.71 mm) for the AHF group. The combined mean IVC-CI values were 61.6% (95% CI, 48.4%-74.7%) for the control group and 30.5% (95% CI, 26.4%-34.6%) for the AHF group.

CONCLUSIONS

Bedside IVC US showed that a statistically significant difference existed in the IVC parameters between patients with and without AHF. Based on mean calculations, an IVC_exp of greater than 2.0 cm and an IVC-CI of less than 30% are reasonable cutoffs to suggest that a patient with acute dyspnea is more likely to have AHF than a non-AHF condition. Given the high degree of heterogeneity across the studies and the high risk of bias, larger randomized studies are warranted to explore the use of IVC US in patients with HF.

Increased right atrial volume measured with cardiac magnetic resonance is associated with worse clinical outcome in patients with pre-capillary pulmonary hypertension

AIMS

Pre-capillary pulmonary hypertension (PHpre-cap ) has a poor prognosis, especially when caused by pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc-PAH). Whether cardiac magnetic resonance (CMR)-based quantification of atrial volumes in PHpre-cap is beneficial in risk assessment is unknown. The aims were to investigate if (i) atrial volumes using CMR are associated with death or lung transplantation in PHpre-cap , (ii) atrial volumes differ among four unmatched major PHpre-cap subgroups, and (iii) atrial volumes differ between SSc-PAH and idiopathic/familial PAH (IPAH/FPAH) when matched for pulmonary vascular resistance (PVR).

METHODS AND RESULTS

Seventy-five PHpre-cap patients (57 ± 19 years, 53 female, 43 de novo) with CMR and right heart catheterization were retrospectively included. Short-axis stacks of cine images were analysed, and right and left atrial maximum (RAVmax and LAVmax ) and minimum volume (RAVmin and LAVmin ) were indexed for body surface area. Increased (mean + 2 SD) and reduced (mean - 2 SD) volumes were predefined from CMR normal values. Transplantation-free survival was lower in patients with increased RAVmax than in those with normal [hazard ratio (HR) = 2.1, 95% confidence interval (CI) 1.1-4.0] but did not differ between those with reduced LAVmax and normal (HR 2.0, 95% CI 0.8-5.1). RAVmax and RAVmin showed no differences among unmatched or matched groups (P = ns). When matched for PVR, LAVmax , LAVmin , and pulmonary artery wedge pressure were reduced in SSc-PAH compared with IPAH/FPAH (95% CI 0.3-21.4, 95% CI 0.8-19.6, and 95% CI 2-7, respectively).

CONCLUSIONS

Patients with PHpre-cap and increased right atrial volume measured with CMR had worse clinical outcome. When matched for PVR, left atrial volume was lower in SSc-PAH than in IPAH/FPAH, consistent with left-sided underfilling, indicating a potential differentiator between the groups.

Comprehensive in-hospital monitoring in acute heart failure: applications for clinical practice and future directions for research. A statement from the Acute Heart Failure Committee of the Heart Failure Association (HFA) of the European Society of Cardiology (ESC)

This paper provides a practical clinical application of guideline recommendations relating to the inpatient monitoring of patients with acute heart failure, through the evaluation of various clinical, biomarker, imaging, invasive and non-invasive approaches. Comprehensive inpatient monitoring is crucial to the optimal management of acute heart failure patients. The European Society of Cardiology heart failure guidelines provide recommendations for the inpatient monitoring of acute heart failure, but the level of evidence underpinning most recommendations is limited. Many tools are available for the in-hospital monitoring of patients with acute heart failure, and each plays a role at various points throughout the patient's treatment course, including the emergency department, intensive care or coronary care unit, and the general ward. Clinical judgment is the preeminent factor guiding application of inpatient monitoring tools, as the various techniques have different patient population targets. When applied appropriately, these techniques enable decision making. However, there is limited evidence demonstrating that implementation of these tools improves patient outcome. Research priorities are identified to address these gaps in evidence. Future research initiatives should aim to identify the optimal in-hospital monitoring strategies that decrease morbidity and prolong survival in patients with acute heart failure.

Relation of Right Atrial Volume, Systemic Venous Dimensions, and Flow Patterns to Right Atrial Pressure in Infants and Children

Echocardiographic assessment of right atrial (RA) volume, inferior vena cava (IVC) diameter, and hepatic vein flow velocity independently correlate with the RA pressure by direct catheter measurement in adults. We prospectively collected invasive RA pressure measurements and echocardiographic data in infants and young children with the goal of developing a predictive model to noninvasively determine normal RA pressure. All subjects had a central venous catheter through which RA pressure could be transduced. Specific inclusion criteria consisted of (1) biventricular heart, (2) absence of inotropes, (3) sinus rhythm, and (4) at least 24 hours from surgery. Two-dimensional echocardiography (2DE)-Doppler and 3DE-Doppler were used to measure RA volume, systemic venous diameters, and flow velocity. Regression equations of RA pressure with RA volume, systemic venous size, and flow velocity were explored. Of 46 studies, 43 (93%) had echocardiograms adequate for analysis. RA pressure did not correlate with body surface area or age (p = 0.69, p = 0.87). The mean indexed RA volume by 3DE-Doppler was significantly higher than by 2DE (p <0.005). On multivariable analysis, only IVC systolic flow velocity and systolic 2D Simpson's derived indexed RA volume demonstrated significant independent correlation with RA pressure, resulting in the equation: RA pressure (mm Hg) = 7.35 - 0.0025 × IVC systolic flow velocity (cm/s) + 0.119 × indexed RA volume by systolic 2D Simpson's (ml/m²). RA pressure did not show correlation with systemic venous diameters or systolic and diastolic flow velocities in the SVC and hepatic veins. In conclusion, regression incorporating 2DE-derived RA volume and IVC systolic flow velocity provided the best noninvasive estimate of normal RA pressure in infants and children. The model derived requires validation in an independent sample.

Reconsideration of Inferior Vena Cava Parameters for Estimating Right Atrial Pressure in an East Asian Population - Comparative Simultaneous Ultrasound-Catheterization Study

BACKGROUND

Ultrasound measurements of the inferior vena cava (IVC) diameter (IVCD), together with its respiratory variation, provide a noninvasive estimate of right atrial pressure (RAP). However, there is a paucity of studies that have compared this technique with simultaneous catheterization. We explored the best cut-off values of IVC parameters for elevated RAP in comparison with RAP measured by catheterization.Methods and Results:We prospectively enrolled 120 East Asian patients who were scheduled for catheterization. The IVCD and IVC collapsibility index (IVCCI) were measured according to the current guidelines. The optimal maximum IVCD (IVCDmax) and IVCCI cut-offs for detecting elevated RAP (RAP ≥10 mmHg) were 17 mm and 40%, respectively. When we combined both in proportion to the guidelines, the sensitivity and specificity for detecting elevated RAP were 75% and 94%, respectively. When the cut-off values from the current guidelines (>21 mm and <50%) were applied, the respective sensitivity and specificity were 42% and 99%. Interestingly, the cut-off value of the optimal IVCDmax indexed by body surface area (11 mm/m²) was similar to previous Western population data. When we combined both cut-off values (11 mm/m²and 40%), the sensitivity and specificity were 75% and 95%, respectively.

CONCLUSIONS

The optimal absolute IVCDmax and IVCCI cut-offs to detect elevated RAP were smaller than those in the current guidelines. Indexed IVCDmax may be an IVC parameter that can be used internationally.

Discriminatory ability of right atrial volumes with two- and three-dimensional echocardiography to detect elevated right atrial pressure in pulmonary hypertension

AIMS

Pulmonary hypertension (PH) patients have high mortality due to right ventricular failure. Predictors of poor prognostic outcome are increased right atrial volume (RAV) and elevated mean right atrial pressure (mRAP). Our aim was to determine whether RAV measured with 2D echocardiography (2DE) and 3D echocardiography (3DE) can detect elevated mRAP in patients evaluated for PH.

METHODS

Of 85 patients prospectively evaluated for PH, 44 patients (63 ± 15 years, 57% female) had 2DE, 3DE and right heart catheterization within 48 h and were in sinus rhythm. Maximum (RAV_max ) and minimum (RAV_min ) volumes were measured with 3DE. 2D maximum RAV and RA area, inferior vena cava diameter and collapsibility were measured. Invasive mRAP > 8 mmHg was predefined as elevated.

RESULTS

RAV_max and RAV_min correlated with mRAP (r = 0·40 and r = 0·35, P<0·05, for both), and so did 2DE maximum RAV (r = 0·42, P = 0·005) and RA area (r = 0·40, P = 0·008). Area under the curve (AUC) from receiver-operating characteristics curves was for 3DE 0·77 for RAV_max , 0·74 for RAV_min , from 2DE, 0·76 for maximum RAV and 0·75 for RA area to discriminate elevated mRAP (P<0·01 for all). PH patients had larger 3D RAV compared with controls (P<0·01). IVC diameter correlated with mRAP (r = 0·41, P = 0·007), but collapsibility did not (P = 0·078). AUC was neither significant for IVC diameter nor for collapsibility for predicting mRAP>8 mmHg. The optimal threshold was 57 ml m^-2 for RAV_max , 31 ml m^-2 for RAV_min and 36 ml m^-2 for 2DE RAV.

CONCLUSIONS

Enlarged RA measures with 2DE and 3DE have better discriminatory ability compared with IVC measures, to detect elevated mRAP in patients evaluated for PH.

The efficacy of sonographic measurement of inferior vena cava diameter as an estimate of central venous pressure

BACKGROUND

Central venous pressure (CVP) and right atrial pressure (RAP) are important parameters in the complete hemodynamic assessment of a patient. Sonographic measurement of the inferior vena cava (IVC) diameter is a non-invasive method of estimating these parameters, but there are limited data summarizing its diagnostic accuracy across multiple studies. We performed a comprehensive review of the existing literature to examine the diagnostic accuracy and clinical utility of sonographic measurement of IVC diameter as a method for assessing CVP and RAP.

METHODS

We performed a systematic search using PubMed of clinical studies comparing sonographic evaluation of IVC diameter and collapsibility against gold standard measurements of CVP and RAP. We included clinical studies that were performed in adults, used current imaging techniques, and were published in English.

RESULTS

Twenty one clinical studies were identified that compared sonographic assessment of IVC diameter with CVP and RAP and met all inclusion criteria. Despite substantial heterogeneity in measurement techniques and patient populations, most studies demonstrated moderate strength correlations between measurements of IVC diameter and collapsibility and CVP or RAP, but more favorable diagnostic accuracy using pre-specified cut points. Findings were inconsistent among mechanically ventilated patients, except in the absence of positive end-expiratory pressure.

CONCLUSION

Sonographic measurement of IVC diameter and collapsibility is a valid method of estimating CVP and RAP. Given the ease, safety, and availability of this non-invasive technique, broader adoption and application of this method in clinical settings is warranted.

Estimating Right Atrial Pressure Using Ultrasounds: An Old Issue Revisited With New Methods

Knowledge of the right atrial pressure (RAP) values is critical to ascertain the existence of a state of hemodynamic congestion, irrespective of the possible presence of signs and symptoms of clinical congestion and cardiac overload that can be lacking in some conditions of concealed or clinically misleading cardiac decompensation. In addition, a more reliable estimate of RAP would make it possible to determine more accurately also the systolic pulmonary arterial pressure with the only echocardiographic methods. The authors briefly illustrate some of the criteria that have been implemented to obtain a non-invasive RAP estimate, some of which have been approved by current guidelines and others are still awaiting official endorsement from the Scientific Societies of Cardiology. There is a representation of the sometimes opposing views of researchers who have studied the problem, and the prospects for development of new diagnostic criteria are outlined, in particular those derived from the matched use of two- and three-dimensional echocardiographic parameters.

Evaluation of right atrial function using right atrial speckle tracking analysis in patients with pulmonary artery hypertension

BACKGROUND

In patients with pulmonary artery hypertension (PAH), right ventricular pressure overload eventually causes right heart failure (RHF), leading to a poor prognosis. Right atrial (RA) overload and RA dysfunction occur in patients with PAH-complicated RHF.

OBJECTIVES

We evaluated RA function using right atrial longitudinal strain (RALS) by two-dimensional speckle tracking echocardiography (2D-STE) and investigated the association between RALS and the severity of RHF in patients with pulmonary artery hypertension (PAH) noninvasively.

METHODS

We performed 2D-STE in 56 PAH patients and 20 normal control subjects. The peak global RALS and peak global RA longitudinal strain rate (RALSR) were analyzed by 2D-STE. Simultaneous right heart catheterization was performed to determine the right atrial pressure (RAP) and cardiac index (CI).

RESULTS

Peak global RALS (34.6 ± 14.1 vs. 58.3 ± 9.9%, p < 0.0001) and peak global RALSR (2.5 ± 1.3 vs. 3.1 ± 1.2 s(-1), p < 0.0001) were significantly lower in PAH patients compared with normal controls. There was a significant negative correlation between peak global RALS and RAP (r = -0.8037, p < 0.0001). There was a significant positive correlation between peak global RALS and CI (r = 0.8179, p < 0.0001). Peak global RALSR was also correlated with RAP (r = -0.7308, p < 0.0001) and CI (r = 0.7596, p < 0.0001).

CONCLUSIONS

RALS and RALSR by 2D-STE were useful for noninvasive evaluation of RA dysfunction and the severity of RHF in patients with PAH.

The right atrium, a forgotten cardiac chamber: An updated review of multimodality imaging

Despite several limitations, two-dimensional echocardiography (2DE) is the standard method for assessing the right atrium (RA) in everyday clinical routine. Cardiac magnetic resonance remains the current "gold standard" for RA visualization and volume quantification. The development of 2DE-derived strain imaging has enabled assessing RA deformation and phasic function in various pathologic conditions. Three-dimensional echocardiography was demonstrated to be more accurate and reproducible than 2DE for cardiac chamber quantification, while also allowing the evaluation of RA phasic function without geometric assumption. The purpose of this review is to summarize currently available data about RA anatomy, phasic function, and mechanics acquired by different imaging modalities.

H3K9 histone methyltransferase G9a ameliorates dilated cardiomyopathy via the downregulation of cell adhesion molecules

Dilated cardiomyopathy (DCM) is one of the leading causes of mortality; however, the underlying molecular mechanisms of DCM remain to be elucidated. H3K9 histone methyltransferase G9a has been previously characterized, although its functions in DCM are not yet understood. Cell adhesion molecules (CAM) are highly expressed in diseased human hearts and were thought to contribute to chronic degeneration in cardiac incompetence; however, it has been suggested that G9a may suppress the effects of CAM. The aim of the present study was to investigate whether G9a decreased the risk of DCM via regulation of CAM expression. A rat model of DCM was induced using furazolidone (FZ) treatment and numerous parameters were examined. G9a RNA interference (RNAi) was applied to primary neonatal cardiomyocytes (PNCs). Reverse transcription quantitative polymerase chain reaction and western blot analyses were used to examine the expression levels of G9a in the DCM model and PNCs. The growth rate of PNCs was evaluated following G9a RNAi and FZ treatment. The results confirmed that the expression levels of G9a were significantly decreased in the DCM model compared with those in the control group (P<0.01). Conversely, CAM expression levels were significantly increased in the DCM model compared with those in the control group (P<0.01). In PNCs, the expression of CAM was upregulated following G9a silencing using RNAi. Following three‑day culture, the growth rate of PNCs was inhibited by 70 and 35% following FZ treatment and G9a RNAi, respectively. In conclusion, G9a ameliorated DCM via downregulation of CAMs, therefore indicating its potential for use in the treatment of DCM.

Non-invasive bedside assessment of central venous pressure: scanning into the future

BACKGROUND

Noninvasive evaluation of central venous pressure (CVP) can be achieved by assessing the Jugular Venous Pressure (JVP), Peripheral Venous Collapse (PVC), and ultrasound visualization of the inferior vena cava. The relative accuracy of these techniques compared to one another and their application by trainees of varying experience remains uncertain. We compare the application and utility of the JVP, PVC, and handheld Mini Echo amongst trainees of varying experience including a medical student, internal medicine resident, and cardiology fellow. We also introduce and validate a new physical exam technique to assess central venous pressures, the Anthem sign.

METHODS

Patients presenting for their regularly scheduled echocardiograms at the hospital echo department had clinical evaluations of their CVP using these non-invasive bedside techniques. The examiners were blinded to the echo results, each other's assessments, and patient history; their CVP estimates were compared to the gold standard level 3 echo-cardiographer's estimates at the completion of the study.

RESULTS

325 patients combined were examined (mean age 65, s.d. 16 years). When compared to the gold standard of central venous pressure by a level 3 echocardiographer, the JVP was the most sensitive at 86%, improving with clinical experience (p<0.01). The classic PVC technique and Anthem sign had better specificity compared to the JVP. Mini Echo estimates were comparable to physical exam assessments.

CONCLUSIONS

JVP evaluation is the most sensitive physical examination technique in CVP assessments. The PVC techniques along with the newly described Anthem sign may be of value for the early learner who still has not mastered the art of JVP assessment and in obese patients in whom JVP evaluation is problematic. Mini Echo estimates of CVPs are comparable to physical examination by trained clinicians and require less instruction. The use of Mini Echo in medical training should be further evaluated and encouraged.

Update on Perioperative Right Heart Assessment Using Transesophageal Echocardiography

Purpose of the review. This review aims to summarize recent findings relevant for perioperative 2- and 3-dimensional imaging of the right heart with transesophageal echocardiography. Special attention is given to developments that are likely to affect future approaches for prevention and therapy of perioperative right heart failure. Recent findings. Three-dimensional transesophageal echocardiography techniques are becoming more common for the evaluation of anatomy, volumes, and functional indices. Summary. Right heart failure continues to contribute to morbidity and mortality in the context of cardiothoracic surgery. The advent and widespread clinical use of innovative tools permitting more accurate echocardiographic assessment of the right heart will open the door to renewed interest in novel therapeutic strategies.