Quantitative Echocardiographic Analysis of the Right Ventricle in Healthy Individuals

Right ventricle: current knowledge of echocardiographic evaluation of this "forgotten" chamber

In the past the right ventricle (RV) has been traditionally regarded as a simple conduit between the venous system and the pulmonary circulation and it has aroused little interest in both clinical and echocardiographic cardiologists to such an extent that it has been defined as the "forgotten chamber." Subsequently it was clearly shown that the right heart (RH) plays an important physiologic role in cardiac activity, and that congenital or acquired alterations in its structure and function have an important prognostic value. Aim of this review is to shed the light on the echocardiographic approach to this cardiac chamber. In this narrative review we critically explored the most recent literature on this topic using PubMed and Medline and examining the most recent guidelines on the echocardiographic approach to the RV. Echocardiographic approach to RV presents some technical difficulties, which stem from the position of the RV inside the thorax and around the LV and from its particular anatomy, which precludes geometric assumptions. However, RV may now be evaluated quantitatively and qualitatively in many ways, and some new methods can partially overcome some of the limits imposed by its complex anatomy, thereby yielding a quantitative evaluation. Furthermore, due to the wide range of pathologies which may involve the RV a disease-oriented approach should be considered in the echocardiographic investigation of right heart disease.

Reference Values of Right Ventricular Volumes and Ejection Fraction by Three-Dimensional Echocardiography in Adults: A Systematic Review and Meta-Analysis

Objective: This study was conducted in order to determine the reference values for right ventricular (RV) volumes and ejection fraction (EF) using three-dimensional echocardiography (3DE) and to identify sources of variance through a systematic review and meta-analysis.

Methods: This systematic review was preregistered with the International Prospective Register of Systematic Reviews (https://www.crd.york.ac.uk/PROSPERO/) (CRD42020211002). Relevant studies were identified by searches of the PubMed, Embase, and Cochrane Library databases through October 12, 2020. Pooled reference values were calculated using the random-effects model weighted by inverse variance. Meta-regression analysis and Egger's test were used to determine the source of heterogeneity. A subgroup analysis was performed to evaluate the reference values across different conditions.

Results: The search identified 25 studies of 2,165 subjects. The mean reference values were as follows: RV end-diastolic volume, 100.71 ml [95% confidence interval (CI), 90.92–110.51 ml); RV end-systolic volume, 44.19 ml (95% CI, 39.05–49.33 ml); RV end-diastolic volume indexed, 57.01 ml/m² (95% CI, 51.93–62.08 ml/m²); RV end-systolic volume indexed, 25.41 ml/m² (95% CI, 22.58–28.24 ml/m²); and RVEF, 56.20% (95% CI, 54.59–57.82%). The sex- and age-specific reference values were assessed according to the studies reporting the values of different sexes and age distributions, respectively. In addition, the vendor- and software-specific reference values were analyzed. The meta-regression analysis revealed that sex, frame rate, pulmonary artery systolic pressure, and software packages were associated with variations in RV volumes (P < 0.05). Inter-vendor and inter-software discrepancies may explain the variability of RVEF.

Conclusions: The reference values for RV volumes and RVEF using 3DE were assessed. The confounders that impacted the variability in RV volumes or RVEF contained the sex, frame rate, pulmonary artery systolic pressure, inter-vendor discrepancies, and inter-software discrepancies.

Assessment of ventricular function in patients of atrial septal defect by strain imaging before and after correction

Background:

Atrial septal defect (ASD) is a common congenital heart disease associated with volume overload of Right ventricle (RV) with variable effect on Left ventricle (LV). Two-dimensional (2D) Strain analysis is a new tool for objective analysis of myocardial function. This prospective study evaluated the systolic function of right and left ventricle by conventional 2D echo and strain echo and measured changes in cardiac hemodynamics that occurred in patients of ASD before and after correction.

Patients and Methods:

2D echo and strain analysis of each patient before and at 48 hrs, 3 months and 6 months after correction was performed. Routine 2D echo parameters and global longitudinal strain of both ventricles were measured.

Result:

Improvement in LV ejection fraction (P = 0.0001) and myocardial performance index (MPI) (P < 0.0001) occurred at the end of 6 months, whereas decrease in RV MPI (P < 0.0001) and tricuspid annular plane systolic excursion (P < 0.0001) became statistically significant after 3 months of ASD correction. In comparison to conventional 2D echo, global longitudinal strain of RV decreased significantly only after 48 hours of ASD correction while there was no improvement in left ventricular global longitudinal strain after 6 month of correction.

Conclusion:

There was improvement in RV function with subtle change in LV function by strain imaging and most of these changes were completed within 6 months of ASD correction and nearly correlated with conventional 2DEchocardiography.

Right ventricular systolic function in hypertensive heart failure

BACKGROUND

Heart failure (HF) is a major cause of cardiovascular admissions and hypertensive heart failure (HHF) is the most common cause of HF admissions in sub-Saharan Africa, Nigeria inclusive. Right ventricular (RV) dysfunction is being increasingly recognized in HF and found to be an independent predictor of adverse outcomes in HF. This study aimed to determine the prevalence of RV systolic dysfunction in HHF by several echocardiographic parameters.

METHODOLOGY

One hundred subjects with HHF were recruited consecutively into the study along with 50 age and sex-matched controls. All study participants gave written informed consent, and had a full physical examination, blood investigations, 12-lead electrocardiogram, and transthoracic echocardiography. RV systolic function was assessed in all subjects using different methods based on the American Society of Echocardiography guidelines for echocardiographic assessment of the right heart in adults. This included tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), and RV systolic excursion velocity by tissue Doppler (S').

RESULTS

RV systolic dysfunction was found in 53% of subjects with HHF by TAPSE, 56% by RV MPI, and 48% by tissue Doppler systolic excursion S'. RV systolic dysfunction increased with reducing left ventricular ejection fraction (LVEF) in subjects with HHF.

CONCLUSION

A high proportion of subjects with HHF were found to have RV systolic functional abnormalities using TAPSE, RV MPI, and RV S'. Prevalence of RV systolic dysfunction increased with reducing LVEF.

Two-dimensional echocardiographic right ventricle measurements adjusted to body mass index and surface area in a normal population

BACKGROUND

To determine reference echocardiographic values in a normal population and assess their correlation with body mass index (BMI) and body surface area.

METHODS

An expert cardiologist performed two-dimensional echocardiography with triplicate right ventricle (RV) size measurements in 80 subjects with normal heart condition. Results were correlated with anthropometric data.

RESULTS

Base-to-apex length in four-chamber view (RVD3) and above-pulmonic valve in short-axis view in males, as well as mid-RV diameter in standard four-chamber view (RVD), basal RV diameter, and mid RV diameter in RV-focused four-chamber view in females, were significantly correlated with BMI. All RV variables were significantly correlated with BMI in 20-30-year-old subjects. All RV variables except RVD3 and above-aortic valve in short-axis view (proximal) were significantly correlated with BMI in 35-55-year-old subjects. All RV parameters were significantly correlated with body surface area, except for RVD and in 20-35-year-old subjects.

CONCLUSIONS

RV echocardiographic values must be adjusted to anthropometric characteristics for proper diagnosis and management of cardiac disorders. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:204-210, 2017.

Accuracy of quantitative echocardiographic measures of right ventricular function as compared to cardiovascular magnetic resonance

Background

Many echocardiographic parameters have been proposed to evaluate right ventricular (RV) systolic function. We comprehensively assessed a wide range of quantitative echocardiographic parameters in a single cohort compared with same-day cardiovascular magnetic resonance (CMR).

Methods and results

92 subjects were examined prospectively: Group 1 consisted of 46 healthy controls (21 males, 33.4 ± 11.4 years), Group 2 consisted of 46 patients (20 males, 38.5 ± 18.9 years) undergoing RV functional assessment by CMR (1.5 T). Echocardiography was performed on the same day as CMR; fractional area change (RVFAC), myocardial performance index via spectral Doppler (RVMPI), RVMPI via Doppler tissue imaging (RVMPI-DTI), peak systolic myocardial velocity by DTI (RVSm), tricuspid annular plane systolic excursion (TAPSE), speckle tracking strain, and three dimensional right ventricular ejection fraction (3DE-RV). Linear regression, Bland–Altman and receiver-operator-characteristic (ROC) analyses were performed. At ROC analysis, the most predictive echocardiographic methods were; RVFAC (AUC = 0.892), RVMPI (AUC 0.785), TAPSE (AUC 0.849) and 3DE-RV (AUC 0.909). 3DE-RV appeared the most accurate compared to CMR, although underestimated true RV volumes.

Conclusion

As compared to CMR; 3DE-RV, RVFAC, TAPSE and RVMPI were the most reliable predictors of RV function. These parameters can be recommended for clinical use.

Gender differences in right ventricular function in patients with non-ischaemic cardiomyopathy

AIM

To evaluate sex-related differences in right ventricular (RV) function, assessed with cardiac magnetic resonance imaging, in patients with stable non-ischaemic dilated cardiomyopathy.

METHODS

Prospective multicentre study. We included 71 patients (38 men) and 14 healthy volunteers.

RESULTS

Mean age was 60.9 ± 12.2 years. Men presented higher levels of haemoglobin and white blood cell counts than women, and performed better in cardiopulmonary stress testing. A total of 24 patients (12 women) presented severe left ventricular (LV) systolic dysfunction, 32 (13 female) moderate and 15 (8 women) mild LV systolic dysfunction. In the group with severe LV systolic dysfunction, average right ventricular ejection fraction (RVEF) was normal in women (52 ± 4 %), whereas it was reduced in men (39 ± 3 %) p = 0.035. Only one woman (8 %) had severe RV systolic dysfunction (RVEF < 35 %) compared with 6 men (50 %) p < 0.001. In patients with moderate and mild LV dysfunction , the mean RVEF was normal in both men and women. In the 14 healthy volunteers, the lowest value of RVEF was 48 % and mean RVEF was normal in women (56 ± 2 %) and in men (51 ±  1 %), p = 0.08.

CONCLUSIONS

In patients with dilated cardiomyopathy, RV systolic dysfunction is found mainly in male patients with severe LV systolic dysfunction.

Peri-operative assessment of right heart function: role of echocardiography

The right heart contributes significantly to overall cardiac function. Right ventricular (RV) haemodynamics and function have been defined to be physiologically different from the left ventricle, and yet independently associated with outcomes in a spectrum of conditions. In particular, RV function has been shown to influence prognosis of patients undergoing surgery. The assessment of right heart function during the intra-operative and immediate postoperative periods plays an important role in the clinical management of patients having surgery. While a number of techniques are available for the assessment of the right heart intra-operatively, echocardiography remains the prime choice being least invasive, relatively safe, readily accessible and cost-effective. Advancements in the field of echocardiographic have improved ability to assess right heart function. This review examines the role echocardiography and advances in this imaging modality in the assessment of right heart function within the peri-operative setting.

Assessment of right ventricular volumes and ejection fraction by echocardiography: from geometric approximations to realistic shapes

Right ventricular volumes and ejection fraction are challenging to assess by echocardiography, but are well established as functional and prognostic parameters. Three-dimensional (3D) echocardiography has become widespread and relatively easy to use, making calculation of these parameters feasible in the large majority of patients. We review past attempts to estimate right ventricular volumes, current strengths and weaknesses of 3D echocardiography for this task, and compare with corresponding data from magnetic resonance imaging.

Validity of the surface electrocardiogram criteria for right ventricular hypertrophy: the MESA-RV Study (Multi-Ethnic Study of Atherosclerosis-Right Ventricle)

OBJECTIVES

The study aimed to assess the diagnostic properties of electrocardiographic (ECG) criteria for right ventricular hypertrophy (RVH) measured by cardiac magnetic resonance imaging (cMRI) in adults without clinical cardiovascular disease.

BACKGROUND

Current ECG criteria for RVH were based on cadaveric dissection in small studies.

METHODS

MESA (Multi-Ethnic Study of Atherosclerosis) performed cMRIs with complete right ventricle (RV) interpretation on 4,062 participants without clinical cardiovascular disease. Endocardial margins of the RV were manually contoured on diastolic and systolic images. The ECG screening criteria for RVH from the 2009 American Heart Association Recommendations for Standardization and Interpretation of the ECG were examined in participants with and without left ventricular (LV) hypertrophy or reduced ejection fraction. RVH was defined using sex-specific normative equations based on age, height, and weight.

RESULTS

The study sample with normal LV morphology and function (n = 3,719) was age 61.3 ± 10.0 years, 53.5% female, 39.6% Caucasian, 25.5% African American, 21.9% Hispanic, and 13.0% Asian. The mean body mass index was 27.9 ± 5.0 kg/m(2). A total of 6% had RVH, which was generally mild. Traditional ECG criteria were specific (many >95%) but had low sensitivity for RVH by cMRI. The positive predictive values were not sufficiently high as to be clinically useful (maximum 12%). The results did not differ based on age, sex, race, or smoking status, or with the inclusion of participants with abnormal LV mass or function. Classification and regression tree analysis revealed that no combination of ECG variables was better than the criteria used singly.

CONCLUSIONS

The recommended ECG screening criteria for RVH are not sufficiently sensitive or specific for screening for mild RVH in adults without clinical cardiovascular disease.

Assessment of left atrial function after percutaneous closure of patent foramen ovale

BACKGROUND

The influence of atrial septal occluders in left atrial (LA) function after percutaneous closure of patent foramen ovale (PFO) has not been thoroughly studied.

METHODS

Twenty-five patients (mean age 40.7 ± 12 years) undergoing percutaneous PFO closure were enrolled in this study. Transthoracic echocardiogram (TTE) was performed 3 and 6 months before the procedure. Volumetric indices (active emptying fraction: LA AEF, expansion index: LA EI, and passive emptying fraction: LA PEF), strain and strain rate (SR), were calculated during the contractile, reservoir, and conduit LA phases for the lateral, anterior, and inferior LA walls with TTE.

RESULTS

After 3 months, a decrease in the SR of the LA anterior wall was observed (from 2.12 ± 0.22 to 1.66 ± 0.26, P < 0.045), while the LA lateral wall strain was found to be increased (from 0.708 ± 0.15 to 0.783 ± 0.159, P < 0.001). Moreover, simultaneously LA AEF was greater compared with baseline (from 31.0 ± 1.6 to 34.0 ± 1.6, P < 0.004). However, all these alterations reversed at 6 months.

CONCLUSIONS

Segmental LA function is altered transiently after percutaneous PFO closure with a septal occlude. The LA anterior wall SR decreases, while the lateral wall strain increases. The impact of these alterations needs further clarification.

Evaluation of TAPSE as a measure of right ventricular output

PURPOSE

This study was designed to show the relationship between tricuspid annular plane systolic excursion (TAPSE) and stroke volume (SV) by thermodilution using three different methods and also to assess whether TAPSE can track hemodynamic changes associated with volume loading and ephedrine administration.

METHODS

This was an observational study in 61 elective patients with a pulmonary artery catheter who were undergoing coronary artery bypass graft surgery in a cardiac surgical centre. We measured TAPSE by three methods using transesophageal echocardiography: M mode, speckle tracking at the lateral wall, and tissue tracking at the inferior wall. There were two interventions: leg raising (volume recruitment) or administration of ephedrine 5 mg iv. Echo and hemodynamic measurements were performed before and after each intervention.

RESULTS

Eleven patients were excluded due to poor imaging. There were 26 patients in the leg raising group and 24 patients in the ephedrine group. The correlation coefficient between stroke volume (SV) and TAPSE by M mode, speckle tracking, and tissue tracking was 0.48, 0.44, and 0.09, respectively. There was a significant increase in SV following each intervention; however, the changes in TAPSE by any method and velocity were not large enough to reach statistical significance.

CONCLUSION

Tricuspid annular plane systolic excursion by M mode and by speckle tracking correlates modestly with SV. There was no correlation between TAPSE and SV by tissue tracking at the inferior wall of the right ventricle. Tricuspid annular plane systolic excursion by M mode and by speckle tracking does not track changes in SV following either volume loading or ephedrine administration.

A novel approach to standard techniques in the assessment and quantification of the interventricular systolic relationship

Background

Blood flow between the right and left ventricles is subject to the continuity equation and systolic ventricular interdependence. Quantification of this relationship might aid in understanding inter-ventricular function. The purpose of this study was to evaluate and quantify ventricular interdependence by directly comparing right and left ventricular systolic function though echocardiographic surrogates of right and left ventricular systolic function such as MAPSE, TAPSE, RV TVI and LV TVI.

Methods

This study prospectively evaluated 51 healthy participants (mean age, 41 ± 17 years) by resting echocardiography. In addition to standard measurements, tricuspid annular plane of systolic excursion, (TAPSE), mitral annular plane of systolic excursion (MAPSE), and the peak annulus systolic velocity of the right ventricular (RVs) and left ventricular (LVs) free walls were measured by M-mode and pulsed wave Doppler tissue echocardiography and further evaluated for variance across age, gender, and body surface area.

Results

TAPSE (22.1 ± 2.9 mm) was over 54.5% greater than MAPSE (14.3 ± 2.6 mm) and RVs was 64.4% greater than LVs. The LV to RV systolic relationship measured by MAPSE/TAPSE and LVs/RVs ratios were 0.66 ± 0.14 and 0.76 ± 0.21 respectively. These values were not significantly affected by age, gender or body surface area (BSA).

Conclusion

MAPSE/TAPSE and LVs/RVs ratios appear stable across age, gender, and BSA potentially making them good surrogates of systolic ventricular relationship and interdependence.

The impact of pulmonary regurgitation on right ventricular regional myocardial function: an echocardiographic study in adults after total repair of tetralogy of Fallot

BACKGROUND

Early results of tetralogy of Fallot (TOF) surgical repair are excellent, but patients are at risk for long-term complications. The purpose of the study was to determine to what extent ultrasonic tissue indices can be helpful in assessing the degree of pulmonary regurgitation (PR).

METHODS

Fifty adults (26 men, 24 women; mean age, 34.4 years) who had undergone TOF correction were studied.

RESULTS

Compared with normal controls, patients had decreased tricuspid annular plane systolic excursion (20.66 vs 26.79 mm, P < .05). In patients with TOF, maximal strain was reduced in all right ventricular free wall and interventricular septal segments. In patients with previous palliative shunts, lower maximal strain for RV basal segment was observed compared with subjects with no palliative surgery (-18.22% vs -22.27%, P < .05). Maximal systolic and early diastolic strain and strain rate values were significantly higher in patients with PR widths ≥ 3 mm compared with patients with PR widths < 3 mm.

CONCLUSIONS

Adults after TOF repair have decreased regional deformation of the right ventricle and intraventricular septum. Prior palliative treatment reduces the indices of right ventricular regional deformation. PR severity can be described by the extent of right ventricular regional deformation.

Do we have two hearts? New insights in right ventricular function supported by myocardial imaging echocardiography

RV performance is difficult to evaluate, given its geometry, interrelationship with the left ventricle, and sensitivity to alterations in pulmonary pressure. This article focuses on some of the challenges related to the assessment of RV function in the setting of the RV's unique anatomic, physiologic, conventional and newer echocardiographic aspects, and therapeutic implications. The majority of proposed methods of echocardiographic assessment of RV function are based on volumetric approximations of the RV. Such approaches have inherent limitations, first as volume-related measures such as EF are load dependent, second because of the complex geometry of the RV. The issue of RV geometry is usually overcome using geometry-independent parameters such as tricuspid annular excursion and the Tei index. The recent introduction of real-time three-dimensional echocardiography and myocardial imaging echocardiography (tissue Doppler imaging, 1D-strain and 2D-strain echocardiography) implied a great progress in echocardiography. Tissue Doppler imaging allows the quantitative assessment of RV systolic and diastolic function by means of measurement of myocardial velocities. Strain measurements have been shown to correlate well with sonomicrometry segment length measurements both in the inflow and outflow tract of the RV and under different loading conditions. Other findings have been reported in chronic and acute clinical settings. Standard and novel echocardiographic methods of assessment of RV size and performance can help clinicians in the treatment of acute and chronic RV failure and contribute to a better understanding of the peculiar chamber-related functional mechanisms in the context of ventricular interdependent independency.

Early right ventricular systolic dysfunction in patients with systemic sclerosis without pulmonary hypertension: a Doppler Tissue and Speckle Tracking echocardiography study

Background

Isovolumetric acceleration (IVA) is a novel tissue Doppler parameter for the assessment of systolic function. The aim of this study was to evaluate IVA as an early parameter for the detection of right ventricular (RV) systolic dysfunction in patients with systemic sclerosis (SSc) without pulmonary hypertension.

Methods

22 patients and 22 gender- and age-matched healthy subjects underwent standard echocardiography with tissue Doppler imaging (TDI) and speckle tracking strain to assess RV function.

Results

Tricuspid annular plane systolic excursion (TAPSE) (23.2 ± 4.1 mm vs. 26.5 ± 2.9 mm, p < 0.006), peak myocardial systolic velocity (Sm) (11.6 ± 2.3 cm/s vs. 13.9 ± 2.7 cm/s, p = 0.005), isovolumetric contraction velocity (IVV) (10.3 ± 3 cm/s vs. 14.8 ± 3 cm/s, p < 0.001) and IVA (2.3 ± 0.4 m/s² vs. 4.1 ± 0.8 m/s², p < 0.001) were significant lower in the patient group. IVA was the best parameter to predict early systolic dysfunction with an area under the curve of 0.988.

Conclusion

IVA is a useful tool with high-predictive power to detect early right ventricular systolic impairment in patients with SSc and without pulmonary hypertension.

Predictors of right ventricular function as measured by tricuspid annular plane systolic excursion in heart failure

Introduction

Tricuspid Annular Plane Systolic Excursion (TAPSE) has independent prognostic value in heart failure patients but may be influenced by left ventricular (LV) ejection fraction. The present study assessed the association of TAPSE and clinical factors, global and regional LV function in 634 patients admitted for symptomatic heart failure.

Methods & Results

TAPSE were correlated with global and regional measures of longitudinal LV function, segmental wall motion scores and measures of diastolic LV function as measured from transthoracic echocardiography.

LV ejection fraction, wall motion index scores, atrio-ventricular annular plane systolic excursion of the mitral annulus were significantly related to TAPSE. Septal and posterior mitral annular plane systolic excursion (β = 0.56, p < 0.0001 and β = 0.35, p = 0.0002 per mm, respectively) and non-ischemic etiology of heart failure (β = 1.3, p = 0.002) were independent predictors of TAPSE, R² = 0.28, p < 0.0001. The prognostic importance of TAPSE was not dependent of heart failure etiology or any of the other clinical factors analyzed, p_interaction = NS.

Conclusion

TAPSE is reduced with left ventricular dysfunction in heart failure patients, in particular with reduced septal longitudinal motion. TAPSE is decreased in patients with heart failure of ischemic etiology. However, the absolute reduction in TAPSE is small and seems to be of minor importance in the clinical utilization of TAPSE whether applied as a measure of right ventricular systolic function or as a prognostic factor.

Assessing fluid responsiveness in critically ill patients: False-positive pulse pressure variation is detected by Doppler echocardiographic evaluation of the right ventricle

OBJECTIVES

To determine whether peak systolic velocity of tricuspid annular motion assessed by tissue Doppler echocardiography (Sta), a right ventricular function parameter, can discriminate patients with true- and false-positive pulse pressure variation. Pulse pressure variation is used to predict fluid responsiveness in mechanically ventilated patients. However, this parameter has been reported to be falsely positive, especially in patients with right ventricular dysfunction.

DESIGN

A prospective study.

SETTING

Medical and surgical intensive care unit of a university hospital.

PATIENTS

Thirty- five mechanically ventilated patients hospitalized for >24 hrs with a pulse pressure variation of >12%.

INTERVENTIONS

Doppler echocardiography (including measurement of Sta and stroke volume) was performed before and after infusion of 500 mL of colloid solution. Patients were classified into two groups according to their response to fluid infusion: responders (at least 15% increase in stroke volume) and nonresponders.

MEASUREMENTS AND MAIN RESULTS

Twenty-three patients (66%) were responders (true-positive group) and 12 (34%) were nonresponders (false-positive group). Before volume expansion, Sta was statistically lower in the nonresponder group (0.13 [0.04] vs. 0.20 [0.05], p = .0004). The area under the curve of the receiver operating characteristic curve was 0.87 (95% confidence interval, 0.74-1). In patients with pulse pressure variation of >12%, a Sta cutoff value of 0.15 m/s discriminated between responders and nonresponders with a sensitivity of 91% (80-100) and a specificity of 83% (62-100).

CONCLUSIONS

A Sta value of <0.15 m/s seems to be an accurate parameter to detect false-positive pulse pressure variation. Echocardiography should therefore be performed before fluid infusion in patients with pulse pressure variation of >12%.

The limited usefulness of real-time 3-dimensional echocardiography in obtaining normal reference ranges for right ventricular volumes

BACKGROUND

To obtain normal reference ranges and intraobserver variability for right ventricular (RV) volume indexes (VI) and ejection fraction (EF) from apical recordings with real-time 3-dimensional echocardiography (RT3DE), and similarly for RV area indexes (AI) and area fraction (AF) with 2-dimensional echocardiography (2DE).

METHODS

166 participants; 79 males and 87 females aged between 29-79 years and considered free from clinical and subclinical cardiovascular disease. Normal ranges are defined as 95% reference values and reproducibility as coefficients of variation (CV) for repeated measurements.

RESULTS

None of the apical recordings with RT3DE and 2DE included the RV outflow tract. Upper reference values were 62 ml/m2 for RV end-diastolic (ED) VI and 24 ml/m2 for RV end-systolic (ES) VI. Lower normal reference value for RVEF was 41%. The respective reference ranges were 17 cm2/m2 for RVEDAI, 11 cm2/m2 for RVESAI and 27% for RVAF. Males had higher upper normal values for RVEDVI, RVESVI and RVEDAI, and a lower limit than females for RVEF and RVAF. Weak but significant negative correlations between age and RV dimensions were found with RT3DE, but not with 2DE. CVs for repeated measurements ranged between 10% and 14% with RT3DE and from 5% to 14% with 2DE.

CONCLUSION

Although the normal ranges for RVVIs and RVAIs presented in this study reflect RV inflow tract dimensions only, the data presented may still be regarded as a useful tool in clinical practice, especially for RVEF and RVAF.

Echocardiographic tissue deformation imaging quantifies abnormal regional right ventricular function in arrhythmogenic right ventricular dysplasia/cardiomyopathy

BACKGROUND

The aim of this study was to determine the accuracy of new quantitative echocardiographic strain and strain-rate imaging parameters to identify abnormal regional right ventricular (RV) deformation associated with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C).

METHODS

A total of 34 patients with ARVD/C (confirmed by Task Force criteria) and 34 healthy controls were prospectively enrolled. Conventional echocardiography, including Doppler tissue imaging (DTI), was performed. Doppler and two-dimensional strain-derived velocity, strain, and strain rate were calculated in the apical, mid, and basal segments of the RV free wall.

RESULTS

RV dimensions were significantly increased in patients with ARVD/C (RV outflow tract 19.3+/-5.2 mm/m2 vs 14.1+/-2.2 mm/m2, P<.001; RV inflow tract 23.4+/-4.8 mm/m2 vs 18.8+/-2.4 mm/m2, P<.001), whereas left ventricular dimensions were not significantly different compared with controls. Strain and strain rate values were significantly lower in patients with ARVD/C in all 3 segments. All deformation parameters showed a higher accuracy to detect functional abnormalities compared with conventional echocardiographic criteria of dimensions or global systolic function. The lowest DTI strain value in any of the 3 analyzed segments showed the best receiver operating characteristics (area under the curve 0.97) with an optimal cutoff value of -18.2%.

CONCLUSIONS

DTI and two-dimensional strain-derived parameters are superior to conventional echocardiographic parameters in identifying ARVD/C. This novel technique may have additional value in the diagnostic workup of patients with suspected ARVD/C.

Role of cardiac magnetic resonance imaging in the management of patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by abnormally elevated blood pressure of the pulmonary circulation that results, over time, from extensive vascular remodeling and increased pulmonary vascular resistance. Recent advances in magnetic resonance imaging (MRI) technology have led to the development of techniques for noninvasive assessment of cardiovascular structure and function, including hemodynamic parameters in the pulmonary circulation, which are superior in their identification of right ventricular morphologic changes. These advantages make cardiac MRI an attractive modality for following up and providing prognoses in patients with PAH. In this review, we summarize recent developments in the use of MRI for the diagnosis, assessment, and ongoing monitoring of patients with PAH. Over the coming decade, it can be anticipated that continued improvements in MRI image acquisition, spatial and temporal resolution, and analytical techniques will result in improved understanding of PAH pathophysiology, diagnosis, and prognostic variables, and will supplement, and may even replace, some of the invasive procedures currently applied routinely to the evaluation of PAH.