Ventricular Function and Dyssynchrony Quantified by Speckle-Tracking Echocardiography in Patients with Acute and Chronic Right Ventricular Pressure Overload

The quest for determination of standard reference values of right ventricular longitudinal systolic strain: a systematic review and meta-analysis

Right ventricular function is strongly associated with clinical outcomes in many conditions, and the evaluation of right ventricle (RV) structure and function in patients with cardiopulmonary disorders is an essential component of clinical management. The objective of this study was to determine the normal ranges of right ventricular longitudinal strain (RVLS) measurements derived by two-dimensional (2D) speckle tracking echocardiography (STE) through a systematic review and meta-analysis. A systematic review was performed using PubMed, Cochrane, ClinicalKey, and CINAHL. Search terms covered the concepts of right ventricle, strain, speckle-tracking, and 2D echocardiography with additional filtering for humans and adults over the last decade. The RV four-chamber longitudinal strain (RV4CLS), RV free wall longitudinal strain (RVFWLS), and free wall longitudinal segmental strain values of healthy individuals without cardiopulmonary diseases from 28 studies were assessed. Weighted means were estimated using random-effects models in a meta-analysis. The results show for RV4CLS -24,91%[CI  - 25.94;  - 23.88, I² 98%], for RVFWLS -27.63%[CI  - 28.78;  - 26.48, I² 98%], for basal RVFWLS -26.65%[CI  - 30.57;  - 22.73, I² 99%], mid RVFWLS -27.61%[CI  - 30.99;  - 24.22, I² 99%] and apical RVFWLS -24.54%[CI  - 26.70;  - 22.38, I² 98%]. This systematic review and meta-analysis showed longitudinal strain values of 2D STE derived RV. No clear reference value for RV strain can be distilled from the literature search due to high statistical heterogeneity between the studies. However, all results of our analysis suggest that the lower reference values for RVLS in the current recommendations with a cut-off value of  - 20% is underestimated.

Evaluation of Right Ventricular Function and Dyssynchrony in a Dog Model of Acute Pulmonary Embolism: Diagnostic Utility and Reversibility

Background

The diagnosis of acute pulmonary thromboembolism is challenging in dogs. Little has been reported on changes in echocardiographic indices in dogs with acute pulmonary thromboembolism. The objective of this study was to validate the relationship between echocardiographic indices and right heart catheterization variables in dogs with acute pulmonary embolism and to identify a useful echocardiographic index for diagnosing acute pulmonary embolism.

Materials and Methods

Six healthy laboratory beagles were included in the study. Echocardiography and right heart catheterization were performed in a dog model of acute pulmonary embolism produced by microsphere injection. Echocardiographic indices, including the right ventricular (RV) Tei index, RV longitudinal strain, and the dyssynchrony index using speckle tracking echocardiography, transmitral flow, and eccentricity index, were measured.

Results

The mean pulmonary arterial pressure increased (22.2 ± 1.2 mmHg) and the blood pressure decreased after microsphere injection. Although the mean pulmonary arterial pressure remained elevated, the blood pressure recovered 2 days after the microsphere injection. Most echocardiographic indices of RV function were significantly impaired following microsphere injection and recovered after 2 days. In contrast, the RV Tei index was significantly impaired after microsphere injection and the impairment persisted after 2 days. Multivariable analysis revealed that the RV Tei index was an independent echocardiographic predictor of pulmonary vascular resistance (β = 0.88, P < 0.001), and transmitral early diastolic wave was an independent predictor of the cardiac index (β = −0.86, P = 0.001).

Conclusions

The RV Tei index is a useful echocardiographic index for diagnosing acute pulmonary embolism. Ventricular interdependence may be an important factor causing low cardiac output in dogs with acute pulmonary embolism.

The evaluation of right ventricle dyssynchrony by speckle tracking echocardiography in systemic sclerosis patients

PURPOSE

Systemic sclerosis (SSc) is associated with right ventricle (RV) remodeling and dysfunction. The primary aim of this study was to evaluate RV dyssynchrony (RV-Dys) in SSc patients using two-dimensional speckle tracking echocardiography (2D-STE).

METHODS

Fifty-five SSc patients with functional class I-II and 45 healthy controls were consecutively included and underwent 2D-STE. RV-Dys was defined as the standard deviation of time to peak strain of mid and basal segments of RV free wall and interventricular septum. SSc group was further classified according to the presence of pulmonary arterial hypertension (PAH). Patients with tricuspid regurgitant velocity >2.8 m/s with additional echocardiographic PAH signs were defined as SSc PAH (+).

RESULTS

SSc patients had lower RV longitudinal strain (RV-LS) (-17.6 ± 4.6% vs. -20.8 ± 2.8%, p < 0.001) and greater RV-Dys (49.9 ± 25.4 ms vs 24.3 ± 11.8 ms, p = 0.006) than controls despite no significant difference in conventional echocardiographic variables regarding RV function. Although SSc PAH(+) patients had lower RV-LS and higher RV-Dys than SSc PAH(-) patients, the differences were not statistically significant. The only independent predictor of RV-Dys was RV-LS (β:-0.324 [-3.89- -0.45]; p = 0.014).

CONCLUSION

SSc patients had not only reduced RV-LS but also impaired RV synchronicity even as conventional echocardiographic variables were preserved.

Defining the reference range for right ventricular systolic strain by echocardiography in healthy subjects: A meta-analysis

BACKGROUND

Right ventricular (RV) systolic strain has recently demonstrated prognostic value in various cardiovascular diseases. Despite this, the reference range including the lower limit of normal (LLN) and factors associated with RV strain measurements are not well-established. This meta-analysis aimed to determine the mean and LLN of two- (2D) and three-dimensional (3D) right ventricular global (RVGLS), free wall (RVFWLS) and interventricular septal wall (IVSLS) longitudinal strains in healthy individuals and factors that affect strain measurements.

METHODS

In this meta-analysis, Pubmed, Embase and Cochrane databases were searched until 31 July 2020 for eligible studies reporting RVGLS, RVFWLS and/or IVSLS in at least 30 healthy subjects. We pooled the means and LLNs of RV strains by two- (2D) and three- (3D) dimensional echocardiography, and performed meta-regression analyses.

RESULTS

From 788 articles screened, 45 eligible studies totaling 4439 healthy subjects were eligible for analysis. Pooled means and LLNs with 95% confidence intervals for 2D- RV strains were RVGLS -23.4% (-24.2%, -22.6%) and -16.4% (-17.3%, -15.5%) in 27 studies; RVFWLS -26.9% (-28.0%, -25.9%) and -18.0% (-19.2%, -16.9%) in 32 studies; and IVSLS -20.4% (-22.0%, -18.9%) and -11.5% (-13.6%, -9.6%) in 10 studies, and similar results for 3D- RV strains. Right ventricular fractional area change and vendor software were associated with 2D-RVGLS and RVFWLS means and LLNs.

CONCLUSION

We reported the pooled means and LLNs of RV systolic strains in healthy subjects, to define thresholds for abnormal, borderline and normal strains. Important factors associated with RV systolic strains include right ventricular fractional area change and vendor software.

Noninvasive Predictors of Functional Capacity in Patients with Pulmonary Hypertension due to Congenital Heart Disease: A Pilot Echocardiography Single-Center Study

Background

Pulmonary hypertension (PH) with congenital heart disease (CHD) affects the functional capacity (FC), quality of life, and survival. However, the importance of different echocardiographic parameters and their correlation with FC is unclear.

Methods and Results

A custom-made sheet for 34 consecutive patients with PH due to CHD was made to include patient's demographic data, underlying cardiac disorder, and FC by 6-min walk test (6MWT). The patients were subdivided into Group 1 with 6MWT < 330 m and Group 2 with 6MWT > 330 m. A cutoff value of 330 m was selected because it reflected the survival and outcome of patients in many studies before. Left ventricle global radial strain, baseline saturation, and saturation after 6MWT showed a significant strong positive correlation with 6MWT (r = 0.755, 0.714, and 0.721, P = 0.001, 0.000, and 0.000, respectively). Multiple regression analysis using a multivariate model showed that the mean pulmonary artery pressure (MPAP) and baseline saturation are the most independent predictors of the FC (P = 0.028 and 0.049, respectively), with a cutoff point for MPAP > 30 mmHg (area under the curve [AUC]: 0.85) with a sensitivity and specificity of 69.23% and 95.24%, respectively, and cutoff point for saturation < 94% (AUC: 0.852) with a sensitivity and specificity of 92.31% and 76.19%, respectively.

Conclusion

The MPAP and the baseline oxygen saturation were the most independent predictors of impaired FC. They can be used for risk stratification and as surrogate predictors of outcome in this group of patients.

Cor pulmonale: the role of traditional and advanced echocardiography in the acute and chronic settings

Cor pulmonale is the condition in which the right ventricle undergoes morphological and/or functional changes due to diseases that affect the lungs, the pulmonary circulation, or the breathing process. Depending on the speed of onset of the pathological condition and subsequent effects on the right ventricle, it is possible to distinguish the acute cor pulmonale from the chronic type of disease. Echocardiography plays a central role in the diagnostic and therapeutic work-up of these patients, because of its non-invasive nature and wide accessibility, providing its greatest usefulness in the acute setting. It also represents a valuable tool for tracking right ventricular function in patients with cor pulmonale, assessing its stability, deterioration, or improvement during follow-up. In fact, not only it provides parameters with prognostic value, but also it can be used to assess the efficacy of treatment. This review attempts to provide the current standards of an echocardiographic evaluation in both acute and chronic cor pulmonale, focusing also on the findings present in the most common pathologies causing this condition.

Role of echocardiography in managing acute pulmonary embolism

The role of echocardiography in acute pulmonary embolism (PE) remains incompletely defined. Echocardiography cannot reliably diagnose acute PE, and it does not improve prognostication of patients with low-risk acute PE who lack other clinical features of right ventricular (RV) dysfunction. Echocardiography, however, may yield additional prognostic information in higher risk patients and can aid in distinguishing acute from chronic RV dysfunction. Specific echocardiographic markers of RV dysfunction have the potential to enhance prognostication beyond existing risk models. Until these markers are subjected to rigorous prospective studies, the therapeutic utility and economic value of echocardiography in acute PE are uncertain.

Right ventricular function and dyssynchrony measured by echocardiography in dogs with precapillary pulmonary hypertension

INTRODUCTION

Assessment of the right ventricular (RV) function by echocardiography is important in dogs with pulmonary hypertension (PH). Few reports are available on RV function and dyssynchrony in dogs, especially in the context of precapillary PH.

ANIMALS

The study included 79 client-owned dogs: 25 dogs with precapillary PH and 54 control dogs.

METHODS

Dogs with precapillary PH were prospectively enrolled between December 2013 and February 2017. The echocardiographic indices of RV function, including RV strain and the dyssynchrony index by speckle-tracking echocardiography, were measured. Multivariate analysis was used to determine independent predictors of the RV dyssynchrony index.

RESULTS

Dogs with precapillary PH showed RV dilation, hypertrophy and right atrial dilation. Impaired echocardiographic indices of RV function, including RV strain, were observed. In addition, RV dyssynchrony occurred in dogs with precapillary PH. Multivariate analysis revealed that tricuspid regurgitation velocity and RV dilation were independent predictors of the RV dyssynchrony index.

CONCLUSIONS

Echocardiographic RV function indices are impaired in dogs with precapillary PH. In addition, RV dilation and elevated systolic pulmonary arterial pressure estimated by echocardiography are associated with RV dyssynchrony.

Acute right heart failure caused by tacrolimus after renal transplantation: Serial observation by speckle tracking and Doppler echocardiography

Tacrolimus is an immunosuppressive agent well known to be capable of producing renal impairment. Acute renal failure with right heart failure caused by tacrolimus is rarely described. We report the findings of one such case in which tacrolimus caused acute renal failure with severe tricuspid regurgitation and right ventricular failure documented by echocardiography.

Right atrial mechanics provide useful insight in pediatric pulmonary hypertension

Right atrial (RA) mechanics have been studied infrequently in children in the past due to technical constraints. With the advent of strain imaging, RA physiology can now be studied in greater detail. The principal aim of this study was to describe functional changes in right heart mechanics of children with idiopathic pulmonary arterial hypertension (PAH), by using new applications of RA strain. In this retrospective study, we evaluated RA mechanics of 20 patients (age range = 3-23 years) with PAH and 18 control patients. RA longitudinal strain (RALS) and longitudinal displacement (LD) were calculated by speckle-tracking echocardiography. RALS was plotted against LD, producing a characteristic strain-displacement (S-D) loop. Standard indices of right heart function and right heart catheterization data were obtained. Patients were clinically subdivided into "compensated" and "decompensated" PAH. A chart review was performed to identify patients who subsequently developed adverse outcomes, including death, awaiting or received lung and/or heart transplantation. RALS was significantly lower in decompensated PAH compared with both controls and compensated PAH. Area enclosed by S-D loops differed significantly between the compensated and decompensated PAH subgroups (5.33 [3.90-9.44] versus 1.83 [1.17-2.36], P < 0.05). S-D loop area and RALS possessed high sensitivity and specificity compared to other parameters for identifying children with PAH who subsequently developed adverse outcomes. In particular, their sensitivities and specificities were greatly superior compared to those of tricuspid annular plane systolic excursion (TAPSE). RALS may represent a useful metric for assessing right ventricular (RV) dysfunction. S-D loops, composed over an entire cardiac cycle, may present useful, composite information regarding both systolic and diastolic right heart function. RA mechanics may serve as useful tools for identifying patients with more severe PAH, who are at risk for future adverse outcomes associated with RV failure.

Speckle tracking echocardiography in the critically ill: enticing research with minimal clinical practicality or the answer to non-invasive cardiac assessment?

Echocardiography is developing rapidly. Speckle tracking echocardiography is the latest semi-automatic tool that has potential to quantitatively describe cardiac dysfunction that may be unrecognised by conventional echocardiography. It is a non-Doppler, angle-independent, feasible and reproducible method to evaluate myocardial function in both non-critically ill and critically ill populations. Increasingly it has become a standard measure of both left and right ventricle function in specific patient groups, e.g. chemotherapy-induced cardiomyopathy or pulmonary hypertension. To date there are few studies in the critically ill, predominantly in sepsis, yet all describe dysfunction beyond standard measures. Other areas of interest include heart-lung interactions, right ventricle function and twist and torsion of the heart. A word of caution is required, however, in that speckle tracking echocardiography is far from perfect and is more challenging, particularly in the critically ill, than implied by many published studies. It takes time to learn and perform and most values are not validated, particularly in the critically ill. We should be cautious in accepting that the latest software used in cardiology cohorts will automatically be the answer in the critically ill. Even with these limitations the technology is enticing and results fascinating. We are uncovering previously undescribed dysfunction and although it currently is essentially a research-based activity, there is great promise as a clinical tool as echocardiography analysis becomes more automated, and potentially speckle tracking echocardiography could help describe cardiac function in critical illness more accurately than is possible with current techniques.

Right ventricular dyssynchrony in pulmonary hypertension: Phase analysis using FDG-PET imaging

BACKGROUND

Right ventricular (RV) performance in patients of pulmonary hypertension (PH) requires optimal assessment. The objective of this study is to develop phase analysis using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging as a feasible tool for evaluation of RV dyssynchrony in PH.

METHODS AND RESULTS

Fifty-four PH patients with well-characterized hemodynamic parameters were enrolled. All subjects performed FDG-PET imaging for RV phase analysis and RV function evaluation. Two-dimensional echocardiography with speckle tracking analysis was conducted to obtain RV time to peak systolic strain (PSST) as a comparison. The median contraction delay difference between RV middle free wall and septum measured by PET phase analysis (RVPDPET) was 20.12° (interquartile range, 4.99°-30.10°). The median difference of PSST between RV middle free wall and middle septal wall (RVPDEcho) measured by echocardiography was 43.98° (interquartile range, 6.25°-72.00°). RVPDPET was well correlated with RVPDEcho (r = 0.685, P < .001). RV phase standard deviation (RVSD) and histogram bandwidth (RVBW) derived from PET phase histogram were significantly correlated with cardiac index, RV ejection fraction, 6-minute walking distance, and serum N-terminal pro B-type natriuretic peptide (NT-proBNP) (RVSD: r = -0.532, P < .001; r = -0.551, P < .001; r = -0.544, P < .001; r = 0.404, P < .01; respectively, RVBW: r = -0.492, P < .001; r = -0.466, P < .001; r = -0.544, P < .001; r = 0.349, P = .01, respectively), while there were no significant correlations between RVSD and RVBW with hemodynamic parameters (right atrial pressure, right ventricular systolic pressure, right ventricular end-diastolic pressure, mean pulmonary artery pressure, and total pulmonary resistance).

CONCLUSIONS

Contraction delays between RV free wall and septum in PH measured by phase analysis and speckle tracking echocardiography were well correlated. RV dyssynchrony measured by phase analysis of FDG-PET was significantly related to RV dysfunction. Phase analysis of FDG-PET is feasible to evaluate RV mechanical dyssynchrony in patients of PH.

Left Ventricular Function in Patients with Pulmonary Arterial Hypertension: The Role of Two-Dimensional Speckle Tracking Strain

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by elevated mean pulmonary arterial pressure with abnormal right ventricular (RV) pressure overload that may alter left ventricular (LV) function. The aim of this study was to assess the impact of RV pressure overload on LV function in PAH patients using two-dimensional (2D) speckle tracking strain.

METHODS

The study enrolled 37 group 1 PAH patients and 38 age- and gender-matched healthy controls. LV longitudinal and radial 2D strains were measured with and without including the ventricular septum. Six-minute walk test (6MWT) and brain natriuretic peptide (BNP) levels were also obtained in patients with PAH.

RESULTS

The mean age of patients was 46.4 ± 14.8 years, 76% women, and 16 patients (43%) had schistosomiasis. Sixteen patients (43%) were in WHO class III or IV under specific treatment for PAH. The overall 6MWT distance was 441 meters, and the BNP levels were 80 pg/mL. Patients with PAH more commonly presented with LV diastolic dysfunction and impairment of RV function when compared to controls. LV global longitudinal and radial strains were lower in patients than in controls (-17.9 ± 2.8 vs. -20.5 ± 1.9; P < 0.001 and 30.8 ± 10.5 vs. 49.8 ± 15.4; P < 0.001, respectively). After excluding septal values, LV longitudinal and radial strains remained lower in patients than in controls. The independent factors associated with global LV longitudinal strain were LV ejection fraction, RV fractional area change, and tricuspid annular systolic motion.

CONCLUSIONS

This study showed impaired LV contractility in patients with PAH assessed by speckle tracking strain, irrespective of ventricular septal involvement. Global LV longitudinal strain was associated independently with RV fractional area change and tricuspid annular systolic motion, after adjustment for LV ejection fraction.

Detrimental Impact of Vasopressin V2 Receptor Antagonism in a SU5416/Hypoxia/Normoxia-Exposed Rat Model of Pulmonary Arterial Hypertension

BACKGROUND

The expression of vasopressin type 2 receptor (V2R) in the lung, and the long-term effects of tolvaptan, a selective V2R antagonist, on pulmonary circulation and right ventricular (RV) remodeling in a pulmonary arterial hypertension (PAH) rat model were evaluated.

METHODS AND RESULTS

Six-week-old male Sprague-Dawley rats were injected subcutaneously with 20 mg/kg of SU5416 and were exposed to hypoxia for 3 weeks followed by re-exposure to normoxia for 7 weeks. These rats showed signs of RV failure and upregulation of V2R and cAMP in the lung tissue at 10 weeks after SU5416 injection. They were then treated with either 0.05% tolvaptan in diet (SUHx+Tolv) or normal diet (SUHx) during 5-10 weeks of SU5416 injection. Normal control rats (Cont) were also used for comparison. SUHx+Tolv had significantly higher pulmonary arterial pressure, more progressive pulmonary arterial remodeling, and more severe myocyte hypertrophy and interstitial myocardial fibrosis in the right ventricle compared with SUHx despite achieving successful preload reduction.

CONCLUSIONS

Chronic vasopressin V2R antagonism may contribute to the worsening of PAH and the development of RV remodeling.

Three-dimensional echocardiography and 2D-3D speckle-tracking imaging in chronic pulmonary hypertension: diagnostic accuracy in detecting hemodynamic signs of right ventricular (RV) failure

BACKGROUND

Our aim was to compare three-dimensional (3D) and 2D and 3D speckle-tracking (2D-STE, 3D-STE) echocardiographic parameters with conventional right ventricular (RV) indexes in patients with chronic pulmonary hypertension (PH), and investigate whether these techniques could result in better correlation with hemodynamic variables indicative of heart failure.

METHODS AND RESULTS

Seventy-three adult patients (mean age, 53±13 years; 44% male) with chronic PH of different etiologies were studied by echocardiography and cardiac catheterization (25 precapillary PH from pulmonary arterial hypertension, 23 obstructive pulmonary heart disease, and 23 postcapillary PH from mitral regurgitation). Thirty healthy subjects (mean age, 54±15 years; 43% male) served as controls. Standard 2D measurements (RV-fractional area change-tricuspid annular plane systolic excursion) and mitral and tricuspid tissue Doppler annular velocities were obtained. RV 3D volumes and global and regional ejection fraction (3D-RVEF) were determined. RV strains were calculated by 2D-STE and 3D-STE. RV 3D global-free-wall longitudinal strain (3DGFW-RVLS), 2D global-free-wall longitudinal strain (GFW-RVLS), apical-free-wall longitudinal strain, basal-free-wall longitudinal strain, and 3D-RVEF were lower in patients with precapillary PH (P<0.0001) and postcapillary PH (P<0.01) compared to controls. 3DGFW-RVLS (hazard ratio 4.6, 95% CI 2.79 to 8.38, P=0.004) and 3D-RVEF (hazard ratio 5.3, 95% CI 2.85 to 9.89, P=0.002) were independent predictors of mortality. Receiver operating characteristic curves showed that the thresholds offering an adequate compromise between sensitivity and specificity for detecting hemodynamic signs of RV failure were 39% for 3D-RVEF (AUC 0.89), -17% for 3DGFW-RVLS (AUC 0.88), -18% for GFW-RVLS (AUC 0.88), -16% for apical-free-wall longitudinal strain (AUC 0.85), 16 mm for tricuspid annular plane systolic excursion (AUC 0.67), and 38% for RV-FAC (AUC 0.62).

CONCLUSIONS

In chronic PH, 3D, 2D-STE and 3D-STE parameters indicate global and regional RV dysfunction that is associated with RV failure hemodynamics better than conventional echo indices.

Is cardiac resynchronization therapy for right ventricular failure in pulmonary arterial hypertension of benefit?

Pulmonary arterial hypertension is a manifestation of a group of disorders leading to pulmonary vascular remodeling and increased pulmonary pressures. The right ventricular (RV) response to chronic pressure overload consists of myocardial remodeling, which is in many ways similar to that seen in left ventricular (LV) failure. Maladaptive myocardial remodeling often leads to intraventricular and interventricular dyssychrony, an observation that has led to cardiac resynchronization therapy (CRT) for LV failure. CRT has proven to be an effective treatment strategy in subsets of patients with LV failure resulting in improvement in LV function, heart failure symptoms, and survival. Current therapy for pulmonary arterial hypertension is based on decreasing pulmonary vascular resistance, and there is currently no effective therapy targeting the right ventricle or maladaptive ventricular remodeling in these patients. This review focuses on the RV response to chronic pressure overload, its effect on electromechanical coupling and synchrony, and how lessons learned from left ventricular cardiac resynchronization might be applied as therapy for RV dysfunction in the context of pulmonary arterial hypertension.

Reference Values for Right Ventricular Strain in Patients without Cardiopulmonary Disease: A Prospective Evaluation and Meta-Analysis

BACKGROUND

Myocardial strain imaging is a sensitive echocardiographic technique for identifying ventricular dysfunction. The aim of this study was to describe a reference range for right ventricular (RV) strain in subjects without cardiopulmonary disease and to report these values from a systematic review and meta-analysis of the current literature.

METHODS

Prospective online measurement of RV free wall longitudinal systolic strain using speckle tracking echocardiography (STE) was performed in 116 subjects with normal echocardiograms and without cardiopulmonary disease or risk factors. A systematic search of studies in EMBASE and Medline reporting RV strain values was performed through February 2014.

RESULTS

The mean age was 48 ± 16 years and 58% were female. Mean RV strain was -26 ± 4%. Ten studies involving a total of 486 patients met our inclusion criteria. The mean age range was 43-57 years and 59% were female. All prior studies were performed with offline strain analysis, and 9 used a GE Healthcare strain analysis software system. The weighted estimate of RV free wall strain measured using tissue Doppler imaging (4 studies) was -27 ± 1% (95% confidence interval [CI] -30% to -25%) and with STE (8 studies, including the current study data) -27 ± 2% (95% CI -29% to -24%), respectively.

CONCLUSIONS

A reference range for RV strain in subjects without cardiopulmonary disease is presented. These data may help facilitate the routine clinical measurement of RV strain in patients referred for right heart echocardiography assessment.

Influence of percutaneous atrial septal defect closure on inter- and intra-ventricular mechanical dyssynchrony in adults: evaluation of strain pattern

Previous studies using speckle-tracking echocardiography (STE) for quantifying the functions of the right and left ventricles (RV and LV, respectively) in the presence of percutaneous atrial septal defect (ASD) closure have focused on the peak systolic strain (PSS). This study investigated changes in the mechanical dyssynchrony of ventricular contraction before and after ASD closure, issues that have been little addressed in the literature. Thirty-one adults with ASD were studied using two-dimensional STE before and 24 h after ASD closure. Thirty-one healthy age- and sex-matched subjects were recruited as controls. Global and segmental PSS values from the longitudinal, circumferential, and radial directions were analyzed. The time to peak systolic strain (PSST) and the standard deviation of the time to peak strain (SDT) among segments in each direction were calculated, to investigate the inter- and intra-ventricular mechanical dyssynchrony in these patients and improvements after closure. Compared to the control group, patients with ASD had higher RV free-wall longitudinal systolic strain, with increased PSST and SDT. The SDT values of the LV longitudinal and circumferential strains were also increased. By 24 h after ASD closure, the RV free-wall longitudinal strain and its PSST and SDT had reverted to normal levels. The LV circumferential strain was increased, and its SDT was decreased. The contraction period of the RV and myocardial contraction dyssynchrony in the RV and LV were increased in ASD patients. The inter- and intra-ventricular mechanical utilities were improved after percutaneous closure of the ASD.