Longitudinal strain quantitates regional right ventricular contractile function

Speckle tracking echocardiography for diagnosis of right ventricular failure in children with totally corrected tetralogy of Fallot in Sulaimani, Iraq

Objectives

The study was aimed at using speckle tracking echocardiography as a novel technique to diagnose right ventricular failure (RVF) in children with total correction of tetralogy of Fallot (TOF) through surgery.

Methods

A quasi-experimental study was performed at the Children's Heart Hospital of Sulaimani for 9 months. A total of 150 children with completely repaired TOF were enrolled to investigate RVF. Conventional echocardiographic data were recorded, including right ventricular (RV) ejection fraction (EF), tricuspid annular plane systolic excursion (TAPSE), myocardial performance index (MPI), and RV end-systolic and diastolic volume (RVESV and RVEDV). Additionally, speckle tracking was performed for the regional and longitudinal strain and strain rate in four-chamber apical view. RVF diagnosis was determined on the basis of electrocardiography measurement of P-wave dispersion, T-wave dispersion, and QRS duration.

Results

Children with repaired TOF who were diagnosed with RVF through conventional echocardiography exhibited abnormalities with respect to children with normal RV function, including a TAPSE of 1.3 ± 0.11 cm, RVEF of 35.5 ± 6.72, RVESV of 69.8 ± 15.13 ml, RVEDV of 110.1 ± 14.13 ml, MPI of 0.60 ± 0.12, and Pmax of 52.4 ± 14.08. The use of speckle tracking in RVF diagnosis revealed a relatively lower longitudinal strain and strain rate (-12.1 ± 2.3 and -0.9 ± 0.3, respectively) in the children with RVF. Moreover, longitudinal right ventricular strain was positively correlated with TAPSE (r = 0.656) and EF (r = 0.675), and negatively correlated with RVEDV (r = -0.684), RVESV (r = -0.718), MPI (r = -0.735), and Pmax (r = -0.767).

Conclusions

The application of speckle tracking with the longitudinal RV strain and strain rate to estimate RV function in children with repaired TOF is a new advanced method that, compared with conventional echo, significantly improves the diagnosis of regional myocardial deformations and cardiac muscle motion velocity.

Bronchopulmonary dysplasia - associated pulmonary hypertension: An updated review

Bronchopulmonary dysplasia (BPD) is the leading cause of chronic lung disease in infants and the commonest complication of prematurity. Advances in respiratory and overall neonatal care have increased the survival of extremely low gestational age newborns, leading to the continued high incidence of BPD. Pulmonary hypertension (PH) represents the severe form of the pulmonary vascular disease associated with BPD, and affects almost one-third of infants with moderate to severe BPD. PH responds suboptimally to pulmonary vasodilators and increases morbidity and mortality in BPD infants. An up-to-date knowledge of the pathogenesis, pathophysiology, diagnosis, treatment, and outcomes of BPD-PH can be helpful to develop meaningful and novel strategies to improve the outcomes of infants with this disorder. Therefore, our multidisciplinary team has attempted to thoroughly review and summarize the latest advances in BPD-PH in preventing and managing this morbid lung disorder of preterm infants.

Right Ventricular Limitation: A Tale of Two Elastances

Right ventricular (RV) dysfunction is a commonly considered cause of low cardiac output in critically ill patients. Its management can be difficult and requires an understanding of how the RV limits cardiac output. We explain that RV stroke output is caught between the passive elastance of the RV walls during diastolic filling and the active elastance produced by the RV in systole. These two elastances limit RV filling and stroke volume and consequently limit left ventricular stroke volume. We emphasize the use of the term "RV limitation" and argue that limitation of RV filling is the primary pathophysiological process by which the RV causes hemodynamic instability. Importantly, RV limitation can be present even when RV function is normal. We use the term "RV dysfunction" to indicate that RV end-systolic elastance is depressed or diastolic elastance is increased. When RV dysfunction is present, RV limitation occurs at lowerpulmonary valve opening pressures and lower stroke volume, but stroke volume and cardiac output still can be maintained until RV filling is limited. We use the term "RV failure" to indicate the condition in which RV output is insufficient for tissue needs. We discuss the physiological underpinnings of these terms and implications for clinical management.

Systolic function in dogs with pulmonic stenosis of different severities and the effect of balloon valvuloplasty

INTRODUCTION/OBJECTIVES

Pulmonic stenosis (PS) is one of the most common congenital heart diseases in dogs leading to right ventricular (RV) pressure overload, myocardial remodeling, and potential RV dysfunction. Our objectives were to investigate the extent of RV systolic dysfunction in canine PS and to examine the immediate influence of balloon valvuloplasty (BV) on systolic function.

ANIMALS, MATERIALS AND METHODS

This prospective study evaluated 72 dogs with PS and 86 healthy dogs. Echocardiographic parameters of systolic function included normalized tricuspid annular plane systolic excursion (N-TAPSE), normalized systolic myocardial tissue Doppler velocity of the lateral tricuspid annulus (N-RVFW-S'), fractional area change, and speckle-tracking longitudinal endocardial RV strain. Forty-four dogs underwent BV and were re-examined after surgery.

RESULTS

Systolic function at the basal segment of the RV was significantly lower in the PS group when compared to healthy dogs (mean N-TAPSE 4.29 ± standard deviation 1.18 mm/kg^0.285 vs. 5.60 ± 1.29 mm/kg^0.285; median N-RVFW-S' 5.28 [lower-upper 25% quantile 4.35-6.43 cm/s/kg^0.186] vs. 7.82 [6.73-8.79 cm/s/kg^0.186]; all P<0.001). Global longitudinal RV endocardial strain showed no significant difference between the two groups (-28.50 ± 6.23% vs. 28.61 ± 4.64%; P=0.886), but segmental strain analyses revealed basal hypo- and potential compensatory hyperkinesis of the apical RVFW. Furthermore, BV affected most parameters of systolic function, but not the segmental strain values and N-TAPSE.

CONCLUSIONS

Right ventricular basal longitudinal systolic function is decreased in dogs with PS in comparison to a healthy cohort. Regional and global function does not necessarily coincide.

Echocardiographic Assessment of Right Ventricular Function in Paediatric Heart Disease: A Practical Clinical Approach

As the right ventricle (RV) plays an integral role in different paediatric heart diseases, the accurate assessment of RV size and function is essential in the diagnosis, management, and prognostication of congenital and acquired cardiac lesions. Yet, echocardiographic evaluation of the RV is challenging because of its complex and variable morphology, its different physiology compared with the left ventricle, and its capability to adapt to different loading conditions associated with congenital and acquired heart diseases within certain ranges. Reliable echocardiographic detection of RV systolic and diastolic dysfunction remains challenging while important for patient management. This review provides an updated, practical approach to assessing RV function in structurally normal hearts and in children with common congenital heart defects and in those with pulmonary hypertension. We also review the impact of tricuspid valve function on RV functional parameters. There is no single functional RV parameter that uniquely describes RV function; instead a combination of different parameters is recommended in clinical practice. Qualitative and quantitative analysis of RV function will be reviewed including more recent techniques such as speckle tracking and 3D echocardiography.

Right Ventricular Myocardial Adaptation Assessed by Two-Dimensional Speckle Tracking Echocardiography in Canine Models of Chronic Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a life-threatening disease in dogs characterized by an increase in pulmonary arterial pressure (PAP) and/or pulmonary vascular resistance. Right ventricle adapts to its pressure overload through various right ventricular (RV) compensative mechanisms: adaptive and maladaptive remodeling. The former is characterized by concentric hypertrophy and increased compensatory myocardial contractility, whereas the latter is distinguished by eccentric hypertrophy associated with impaired myocardial function. Objectives: To evaluate the RV adaptation associated with the increase of PAP using two-dimensional speckle tracking echocardiography. Animals: Seven experimentally induced PH models. Methods: Dogs were anesthetized and then a pulmonary artery catheter was placed via the right jugular vein. Canine models of PH were induced by the repeated injection of microspheres through the catheter and monitored pulmonary artery pressure. Dogs were performed echocardiography and hemodynamic measurements in a conscious state when baseline and systolic PAP (sPAP) rose to 30, 40, 50 mmHg, and chronic phase. The chronic phase was defined that the sPAP was maintained at 50 mmHg or more for 4 weeks without injection of microspheres. Results: Pulmonary artery to aortic diameter ratio, RV area, end-diastolic RV wall thickness, and RV myocardial performance index were significantly increased in the chronic phase compared with that in the baseline. Tricuspid annular plane systolic excursion was significantly decreased in the chronic phase compared with that in the baseline. The RV longitudinal strain was significantly decreased in the sPAP30 phase, increased in the sPAP40 and sPAP50 phases, and decreased in the chronic phase. Conclusions: Changes in two-dimensional speckle tracking echocardiography-derived RV longitudinal strain might reflect the intrinsic RV myocardial contractility during the PH progression, which could not be detected by conventional echocardiographic parameters.

Multimodality imaging of the ischemic right ventricle: an overview and proposal of a diagnostic algorithm

Right ventricular (RV) involvement is frequently detected in patients presenting with acute left ventricular myocardial infarction. The ischemic right ventricle carries a dismal outcome by predisposing the heart to arrhythmic events and mechanical or hemodynamic complications. A comprehensive RV evaluation by multimodality imaging could guide clinical practice but has always been a conundrum for the imagers. Two-dimensional echocardiography is the best first-line tool due to its availability of bedside capabilities. More advanced imaging techniques provide a more comprehensive evaluation of the complex RV geometry but are mostly reserved for the post-acute setting. Three-dimensional echocardiography has improved the evaluation of RV volumes and function. The recent application of speckle-tracking echocardiography to the right ventricle appears promising, allowing the earlier detection of subtle RV dysfunction. Cardiac magnetic resonance imaging is considered the gold standard for the RV assessment. Cardiac multidetector computed tomography could be a reliable alternative. The aim of this review is to focus on the growing importance of multimodality imaging of the ischemic right ventricle and to propose a diagnostic algorithm, in order to reach a comprehensive assessment of this too frequently neglected chamber.

What are the echocardiographic findings of acute right ventricular strain that suggest pulmonary embolism?

INTRODUCTION

Pulmonary embolism (PE) is a potentially fatal disease encountered in the hospital setting. Prompt diagnosis and management can improve outcomes and survival. Unfortunately, a PE may be difficult to diagnose in a timely manner. Point-of-care ultrasound (POCUS) can assist in the evaluation for suspected PE by assessing for acute right ventricular strain. Physicians should thus be aware of these echocardiographic findings.

OBJECTIVE

This manuscript will review ten echocardiographic findings of right ventricular strain that may suggest a diagnosis of PE. It will provide a description of each finding along with the associated pathophysiology. It will also summarize the literature for the diagnostic utility of echocardiography for this indication, while providing reference parameters where applicable. Along with labeled images and video clips, the review will then illustrate how to evaluate for each of the ten findings, while offering pearls and pitfalls in this bedside evaluation.

DISCUSSION

The ten echocardiographic findings of right ventricular strain are: increased right ventricle: left ventricle size ratio, abnormal septal motion, McConnell's sign, tricuspid regurgitation, elevated pulmonary artery systolic pressure, decreased tricuspid annular plane systolic excursion, decreased S', pulmonary artery mid-systolic notching, 60/60 sign, and speckle tracking demonstrating decreased right ventricular free wall strain.

CONCLUSIONS

Physicians must recognize and understand the echocardiographic findings and associated pathophysiology of right ventricular strain. In the proper clinical context, these findings can point toward a diagnosis of PE and thereby lead to earlier initiation of directed management.

Advanced imaging of right ventricular anatomy and function

Right ventricular (RV) size and function are important predictors of cardiovascular morbidity and mortality in patients with various conditions. However, non-invasive assessment of the RV is a challenging task due to its complex anatomy and location in the chest. Although conventional echocardiography is widely used, its limitations in RV assessment are well recognised. New techniques such as three-dimensional and speckle tracking echocardiography have overcome the limitations of conventional echocardiography allowing a comprehensive, quantitative assessment of RV geometry and function without geometric assumptions. Cardiac magnetic resonance (CMR) and CT provide accurate assessment of RV geometry and function, too. In addition, tissue characterisation imaging for myocardial scar and fat using CMR and CT provides important information regarding the RV that has clinical applications for diagnosis and prognosis in a broad range of cardiac conditions. Limitations also exist for these two advanced modalities including availability and patient suitability for CMR and need for contrast and radiation exposure for CT. Hybrid imaging, which is able to integrate anatomical information (usually obtained by CT or CMR) with physiological and molecular data (usually obtained with positron emission tomography), can provide optimal in vivo evaluation of Rv functional impairment. This review summarises the clinically useful applications of advanced echocardiography techniques, CMR and CT for comprehensive assessment of RV size, function and mechanics.

Right Ventricular Global Longitudinal Strain and Outcomes in Heart Failure with Preserved Ejection Fraction

BACKGROUND

Right ventricular (RV) strain has emerged as an accurate tool for RV function assessment and is a powerful predictor of survival in patients with heart failure with reduced ejection fraction. However, its prognostic impact in patients with heart failure with preserved ejection fraction (HFpEF) remains unclear. The aim of this study was to compare the prognostic value of RV global longitudinal strain (RVGLS) by two-dimensional speckle-tracking echocardiographic (STE) imaging in patients with HFpEF against conventional RV function parameters.

METHODS

Patients with HFpEF were prospectively recruited, and 149 of 183 (81%) with analyzable STE RVGLS images constituted the final study population (mean age, 78 ± 9 years; 61% women), compared with 28 control subjects of similar age and sex. All control subjects and 120 patients also underwent cardiac magnetic resonance imaging. Patients were followed up for a primary end point of all-cause mortality and first heart failure hospitalization, and Cox regression analysis was performed.

RESULTS

Mean STE RVGLS was significantly altered in patients with HFpEF compared with control subjects (-21.7 ± 4.9% vs -25.9 ± 4.2%, P < .001). STE RVGLS correlated well with RV ejection fraction by cardiac magnetic resonance (r = -0.617, P < .001). Twenty-eight patients with HFpEF (19%) had impaired STE RVGLS (>-17.5%). During a mean follow-up period of 30 ± 9 months, 91 patients with HFpEF (62%) reached the primary end point. A baseline model was created using independent predictors of the primary end point: New York Heart Association functional class III or IV, hemoglobin level, estimated glomerular filtration rate, and the presence of moderate or severe tricuspid regurgitation. Impaired STE RVGLS provided significant additional prognostic value over this model (χ² to enter = 7.85, P = .005). Impaired tricuspid annular plane systolic excursion and fractional area change, however, did not.

CONCLUSIONS

In patients with HFpEF, impaired RVGLS has strong prognostic value. STE RVGLS should be considered for systematic evaluation of RV function to identify patients at high risk for adverse events.

Novel Strategies to Reduce Pulmonary Hypertension in Infants With Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a developmental lung disorder of preterm infants primarily caused by the failure of host defense mechanisms to prevent tissue injury and facilitate repair. This disorder is the most common complication of premature birth, and its incidence remains unchanged over the past few decades. Additionally, BPD increases long-term cardiopulmonary and neurodevelopmental morbidities of preterm infants. Pulmonary hypertension (PH) is a common morbidity of BPD. Importantly, the presence of PH increases both the short- and long-term morbidities and mortality in BPD infants. Further, there are no curative therapies for this complex disease. Besides providing an overview of the pathogenesis and diagnosis of PH associated with BPD, we have attempted to comprehensively review and summarize the current literature on the interventions to prevent and/or mitigate BPD and PH in preclinical studies. Our goal was to provide insight into the therapies that have a high translational potential to meaningfully manage BPD patients with PH.

Early Right Ventricular Systolic Dysfunction and Pulmonary Hypertension Are Associated With Worse Outcomes in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

The prevalence and importance of early right ventricular dysfunction and pulmonary hypertension in pediatric acute respiratory distress syndrome are unknown. We aimed to describe the prevalence of right ventricular dysfunction and pulmonary hypertension within 24 hours of pediatric acute respiratory distress syndrome diagnosis and their associations with outcomes.

DESIGN

Retrospective, single-center cohort study.

SETTING

Tertiary care, university-affiliated PICU.

PATIENTS

Children who had echocardiograms performed within 24 hours of pediatric acute respiratory distress syndrome diagnosis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between July 1, 2012, and June 30, 2016, 103 children met inclusion criteria. Echocardiograms were analyzed using established indices of right ventricular and left ventricular systolic function and for evidence of pulmonary hypertension. Echocardiographic abnormalities were common: 26% had low right ventricular fractional area change, 65% had low tricuspid annular plane systolic excursion, 30% had low left ventricular fractional shortening, and 21% had evidence of pulmonary hypertension. Abnormal right ventricular global longitudinal strain and abnormal right ventricular free wall strain were present in 35% and 40% of patients, respectively. No echocardiographic variables differed between or across pediatric acute respiratory distress syndrome severity. In multivariable analyses, right ventricular global longitudinal strain was independently associated with PICU mortality (odds ratio, 3.57 [1.33-9.60]; p = 0.01), whereas right ventricular global longitudinal strain, right ventricular free wall strain, and the presence of pulmonary hypertension were independently associated with lower probability of extubation (subdistribution hazard ratio, 0.46 [0.26-0.83], p = 0.01; subdistribution hazard ratio, 0.58 [0.35-0.98], p = 0.04; and subdistribution hazard ratio, 0.49 [0.26-0.92], p = 0.03, respectively).

CONCLUSIONS

Early ventricular dysfunction and pulmonary hypertension were detectable, prevalent, and independent of lung injury severity in children with pediatric acute respiratory distress syndrome. Right ventricular dysfunction was associated with PICU mortality, whereas right ventricular dysfunction and pulmonary hypertension were associated with lower probability of extubation.

Two-dimensional Echocardiographic Assessment of Myocardial Strain: Important Echocardiographic Parameter Readily Useful in Clinical Field

Echocardiography is the first and is the most-available imaging modality for many cardiovascular diseases, and echocardiographic parameters can give much important information for diagnosis, treatment, and prognostic evaluations. Left ventricular ejection fraction (LVEF) is the most commonly used echocardiographic parameter for left ventricular (LV) systolic function. Although LVEF is used routinely in daily practice, it is calculated from volumetric change without representing true myocardial properties. Recently, strain echocardiography has been used to objectively measure myocardial deformation. Myocardial strain can give accurate information about intrinsic myocardial function, and it can be used to detect early-stage cardiovascular diseases, monitor myocardial changes with specific therapies, differentiate cardiomyopathies, and predict the prognosis of several cardiovascular diseases. Although strain echocardiography has been applied to measure the right ventricle and left atrium, in addition to analyzing the LV, many cardiologists who are not imaging specialists are unaware of its clinical use and importance. Therefore, this review describes the measurement and clinical utility of 2-dimensional strain analysis in various cardiovascular diseases.

Diagnosis and Pathophysiological Mechanisms of Group 3 Hypoxia-Induced Pulmonary Hypertension

PURPOSE OF REVIEW

Group 3 hypoxia-induced pulmonary hypertension (PH) is an important and increasingly diagnosed condition in both the pediatric and adult population. The majority of pulmonary hypertension studies to date and all three classes of drug therapies were designed to focus on group 1 PH. There is a clear unmet medical need for understanding the molecular mechanisms of group 3 PH and a need for novel non-invasive methods of assessing PH in neonates.

RECENT FINDINGS

Several growth factors are expressed in patients and in animal models of group 3 PH and are thought to contribute to the pathophysiology of this disease. Here, we review some of the findings on the roles of vascular endothelial growth factor A (VEGFA), platelet-derived growth factor B (PDGFB), transforming growth factor-beta (TGFB1), and fibroblast growth factors (FGF) in PH. Additionally, we discuss novel uses of echocardiographic parameters in assessing right ventricular form and function. FGF2, TGFB, PDGFB, and VEGFA may serve as biomarkers in group 3 PH along with echocardiographic methods to diagnose and follow right ventricle function. FGFs and VEGFs may also function in the pathophysiology of group 3 PH.

A fiduciary marker-based framework to assess heterogeneity and anisotropy of right ventricular epicardial strains in the beating ovine heart

Quantifying ventricular deformation in health and disease is critical to our understanding of normal heart function, heart disease mechanisms, and the effect of medical treatments. Imaging modalities have been developed that can measure ventricular deformation non-invasively. However, because of the small thickness, complex shape, and anatomic position of the right ventricle, using these technologies to determine its deformation remains challenging. Here we develop a first fiduciary marker-based method to assess heterogeneity and anisotropy of right ventricular epicardial strain across the entire free wall. To this end, we combine a high-density array of sonomicrometry crystals implanted across the entire right ventricular epicardial surface with a subdivision surface algorithm and a large deformation kinematics framework. We demonstrate our approach on four beating ovine hearts and present a preliminary regional analysis of circumferential, longitudinal, and areal strain. Moreover, we illustrate maps of the same strains across the entire right ventricular epicardial surface to highlight their spatial heterogeneity and anisotropy. We observe in these animals that RV epicardial strains vary throughout the cardiac cycle, are heterogeneous across the RV free wall, and are anisotropic with larger compressive strains, i.e., contraction, in the longitudinal direction than in the circumferential direction. Average peak compressive strains vary by region between -3.34% and -8.29% in circumferential direction, and -4.02% and -10.57% in longitudinal direction. In summary, we introduce an experimental framework that will allow us to study disease- and device-induced deformations, and long-term consequences of these deformations, including heterogeneous and anisotropic effects.

Strain Analysis of the Right Ventricle Using Two-dimensional Echocardiography

Right ventricular (RV) systolic dysfunction has been identified as an independent prognostic marker of many cardiovascular diseases. However, there are problems in measuring RV systolic function objectively and identification of RV dysfunction using conventional echocardiography. Strain echocardiography is a new imaging modality to measure myocardial deformation. It can measure intrinsic myocardial function and has been used to measure regional and global left ventricular (LV) function. Although the RV has different morphologic characteristics than the LV, strain analysis of the RV is feasible. After strain echocardiography was introduced to measure RV systolic function, it became more popular and was incorporated into recent echocardiographic guidelines. Recent studies showed that RV global longitudinal strain (RVGLS) can be used as an objective index of RV systolic function with prognostic significance. In this review, we discuss RVGLS measurement, normal reference values, and the clinical importance of RVGLS.

Immediate impact of percutaneous transvenous mitral commisurotomy on right ventricle longitudinal strain in patients of mitral stenosis

BACKGROUND

Right ventricular (RV) function has prognostic value in terms of survival and symptoms in patients with mitral stenosis (MS). The aim of the study was to assess RV function by strain analysis in the patients of mitral stenosis and the effect of percutaneous transvenous mitral commisurotomy (PTMC) on it.

METHODS

Eighty patients of severe mitral stenosis without overt right heart failure and normal sinus rhythm undergoing PTMC were included. Conventional echocardiography and RV function by TDI-derived longitudinal strain and strain rate were assessed prior and 24 hours post PTMC and compared with 40 healthy age-matched controls.

RESULTS

Eighty subjects (mean age 31 + 10 years, 70% females) were included. Patients with MS had significantly lower RV strain of basal and mid-free wall, tricuspid annular plane systolic excursion (TAPSE), and RV fractional area change (FAC) as compared to controls. There was a significant increase in pre- and post-PTMC in TAPSE (19.5 ± 2.7 mm vs 21.4 ± 3.3 mm; P < 0.001), RV basal free wall longitudinal strain (-24.4 + 6.1% vs -27.7 + 5.8%; P < 0.001), and right ventricle mid-free wall longitudinal strain (-25.6 + 5.5% vs -28.6 + 5.1%; P < 0.001), respectively. There was no significant change in RV Tei index (0.43 + 0.06 vs 0.41 + 0.03; P = 0.06). There was a significant negative correlation between RV longitudinal strain and right ventricle systolic pressure, left atrium diameter, RV Tei index, and pulmonary capillary wedge pressure, and positive correlation between RV FAC and RV TAPSE.

CONCLUSION

Patients with severe MS with normal RV systolic function had decreased RV strain, which was significantly increased after a successful PTMC with reduction in afterload.

Longitudinal Changes in Right Ventricular Function in Tetralogy of Fallot in the Initial Years after Surgical Repair

BACKGROUND

Right ventricular (RV) dysfunction is associated with adverse long-term outcomes in patients with tetralogy of Fallot. Little is known about RV function in the first years after surgical repair. The aim of this study was to investigate perioperative changes in myocardial deformation using global longitudinal strain.

METHODS

A retrospective analysis of patients with surgically repaired tetralogy of Fallot was performed. Global longitudinal peak systolic RV strain was measured on early postoperative echocardiograms, two subsequent postoperative echocardiograms through 2 years postoperatively, and preoperative echocardiograms, when available. Preoperative and late follow-up strain was compared with strain in 0- to 8-month-old and 1- to 4-year-old control subjects, respectively.

RESULTS

Forty-seven patients were included. Compared with postoperative strain (7 ± 7 days postoperatively), strain at follow-up 1 (8.3 ± 4 months postoperatively) was significantly improved (-12.3 ± 3.3% vs -18.8 ± 2.5%, P < .001), with no additional improvement 23.2 ± 6 months postoperatively (-18.8 ± 2.5% vs -19.8 ± 3.1%, P = .12). Postoperative strain was worse than preoperative strain (n = 25, -12.5 ± 3.6% vs -18.4 ± 2.9%, P < .001). Compared with control subjects, preoperative strain was similar (-19.3 ± 3.8% vs -18.4 ± 2.9%, P = .30), though late follow-up strain was significantly worse (-27.7 ± 2.8% vs -19.8 ± 3.1%, P < .001).

CONCLUSIONS

RV global longitudinal strain worsens in the early postoperative period following surgical repair of tetralogy of Fallot but recovers through 2 postoperative years. Despite recovery to preoperative values, the presence of RV dysfunction compared with control subjects suggests that long-term dysfunction may begin early. The trajectory of RV dysfunction through the later years needs further study.

The obesity paradox: the protective effect of obesity on right ventricular function using echocardiographic strain imaging in patients with pulmonary hypertension

BACKGROUND

Obesity is associated with right ventricular (RV) dysfunction, but its effect on RV remodeling in patients with pulmonary hypertension (PHTN) has not been studied. We evaluated the effect of obesity, and its interplay with diabetes, in patients with PHTN using RV echocardiographic strain imaging.

METHODS

One hundred eighty-five patients underwent echocardiographic imaging and pulmonary artery pressure was calculated using tricuspid regurgitation jet velocity. From focused RV apical-four-chamber view, global and mid peak systolic RV free wall longitudinal strain (FWLS) was calculated using speckle-tracking software.

RESULTS

Global and mid RV FWLS in patients with PHTN (N.=84) was lower (-16.8±7 vs. 18.9±6.3, P=0.035 and -11.2±12.8 vs. -18.9±9.2, P=0.002 respectively) compared with patients without PHTN (N.=101). Among patients without PHTN, obese patients (BMI>30) had lower global and mid RV FWLS (-17.2±6.2 vs. -20.3±5.7, P=0.012 and -17.6±7.2 vs. -21.9±7.3, P=0.004), even after excluding diabetic patients (Mid RV FWLS -18.2±6.8 vs. -22.1±8, P=0.032). Among patients with PHTN, obese patients had similar RV FWLS compared with non-obese patients (P=0.46). However, on excluding diabetic patients from PHTN group, obese patients with PHTN had higher global and mid RV FWLS (-21.7±5.7 vs. -16.1±8, P=0.017 and 23.8±4.8 vs. -17±9.4, P=0.009 respectively) compared to non-obese patients which suggests a protective effect of obesity on RV function in patients with PHTN.

CONCLUSIONS

Obesity is associated with subclinical RV dysfunction as assessed by RV strain imaging, but paradoxically it may confer a protective effect on RV function once the patient develops PHTN. Future studies should evaluate the clinical impact of this paradox.

Right ventricular function mirrors clinical improvement with use of prostacyclin analogues in pediatric pulmonary hypertension

Pulmonary hypertension (PH) causes significant morbidity and mortality in children due to right ventricular (RV) failure. We sought to determine the effect of prostacyclin analogues on RV function assessed by echocardiography in children with PH. We conducted a retrospective cohort study of children with PH treated with a prostacyclin analogue (epoprostenol or treprostinil) between January 2001 and August 2015 at our center. Data were collected before initiation of treatment (baseline) and at 1–3 and 6–12 months after. Protocolized echocardiogram measurements including tricuspid annular plane systolic excursion (TAPSE) and RV global longitudinal strain were made with blinding to clinical information. Forty-nine individuals (65% female), aged 0–29 years at the time of prostacyclin initiation were included. Disease types included pulmonary arterial hypertension (idiopathic [35%], heritable [2%], and congenital heart disease-associated [18%]), developmental lung disease (43%), and chronic thromboembolic PH (2%). Participants received intravenous (IV) epoprostenol (14%) and IV/subcutaneous (SQ) (67%) or inhaled (18%) treprostinil. Over the study period, prostacyclin analogues were associated with improvement in TAPSE (P = 0.007), RV strain (P < 0.001), and qualitative RV function (P = 0.037) by echocardiogram, and BNP (P < 0.001), functional class (P = 0.047) and 6-min walk distance (P = 0.001). TAPSE and strain improved at early follow up (P = 0.05 and P = 0.002, respectively) despite minimal RV pressure change. In children with PH, prostacyclin analogues are associated with an early and sustained improvement in RV function measured as TAPSE and strain as well as clinical markers of PH severity. RV strain may be a sensitive marker of RV function in this population.

Vendor-Neutral Right Ventricular Strain Measurement

OBJECTIVE

To test the feasibility and reliability of using a vendor-neutral platform to evaluate right ventricular (RV) strain. Reliability was determined by comparing intra- and inter-observer variability between RV strain assessments. The secondary objective was to assess strain's correlation with conventional RV functional parameters to evaluate its feasibility as a RV systolic functional assessment tool.

DESIGN

This is a retrospective study.

SETTING

Tertiary hospital.

PARTICIPANTS

A total of 15 patients who underwent elective coronary artery bypass graft surgery were selected for inclusion.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Images obtained during routine, intraoperative, two-dimensional transesophageal echocardiography (2D TEE) were assessed for longitudinal strain (LS) and conventional parameters, including fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), Doppler tissue imaging (DTI)-derived tricuspid lateral annular systolic velocity wave (S'), and RV dimensions using vendor-neutral software. There was good to excellent intra- and inter-observer reproducibility (intraclass correlation coefficient [ICC] from 0.75 to 1.00) with the exception of basal free wall longitudinal strain (FWLS) (for intra- and inter-observer reproducibility, ICC = 0.670 and 0.749, respectively). FWLS and global longitudinal strain (GLS) showed moderate to strong positive correlation with FAC, TAPSE, and S' (correlation coefficients from 0.667 to 0.721).

CONCLUSION

It is feasible to assess RV strain across multiple platforms in a reproducible and reliable fashion. Furthermore, RV strain demonstrated good correlation with conventional RV functional parameters, suggesting its feasibility as a sensitive RV function assessment tool.

Echocardiographic assessment of regional right ventricular systolic function using two-dimensional strain echocardiography and evaluation of the predictive ability of longitudinal 2D-strain imaging for pulmonary arterial hypertension in systemic sclerosis patients

Systemic sclerosis (SSc) is a generalized connective tissue disorder, and SSc patients are at risk of developing pulmonary arterial hypertension (PAH). The aims of this study are to evaluate the right ventricular regional systolic function using two-dimensional speckle-tracking echocardiography (2D STE) and to determine the predictive ability of peak longitudinal systolic strain (PLSS) at the RV lateral wall for PAH in SSc patients. 80 SSc patients (mean age 51 ± 12 years) were included in the study. Echocardiography and 2D STE were performed at baseline and after 12 months. RHC was performed only in SSc patients with clinical indications. PLSS at the apical segment of the RV free wall was significantly impaired in PAH patients compared with non-PH patients (-14.6 ± 5.9 vs. - 22.2 ± 7.5%, p = 0.034). PLSS at the basal, mid, and apical segments of the RV free wall was lower in both groups at follow-up compared to baseline, but the drop in strain values was statistically significant only in the non-PH group (p < 0.05). Right atrial area (OR 1.758; p = 0.023), peak tricuspid regurgitation velocity (OR 24.23; p = 0.011) and PLSS at the apical segment of the RV lateral wall (OR 2.47; p = 0.005) were independent predictors of PAH. A cut-off value of - 14.48% PLSS at the apical segment of the RV lateral wall resulted in 100% specificity for predicting PAH in SSc patients. RV pressure overload affects RV systolic function as manifested by impaired RV longitudinal deformation. Evaluating RV regional systolic function with 2D STE could be useful as an additional echocardiographic parameter for screening PAH in SSc patients.

2D speckle tracking echocardiography of the right ventricle free wall in SCUBA divers after single open sea dive

The presence of circulating gas bubbles and their influence on pulmonary and right heart hemodynamics was reported after uncomplicated self-contained underwater breathing apparatus (SCUBA) dive(s). Improvements in cardiac imaging have recently focused great attention on the right ventricle (RV). The aim of our study was to evaluate possible effects of a single air SCUBA dive on RV function using 2D speckle tracking echocardiography in healthy divers after single open sea dive to 18 meters of seawater, followed by bottom stay of 47 minutes with a direct ascent to the surface. Twelve experienced male divers (age 39.5 ± 10.5 years) participated in the study. Echocardiographic assessment of the right ventricular function (free wall 2 D strain, tricuspid annular planes systolic excursion [TAPSE], lateral tricuspid annular peak systolic velocity [RV s`] and fractional area change [FAC]) was performed directly prior to and 30, 60, 90 and 120 minutes after surfacing. Two-dimensional strain of all three segments of free right ventricular wall showed a significant increase in longitudinal shortening in post-dive period for maximally 26% (basal), 15.4% (mid) and 16.3% (apical) as well as TAPSE (11.6%), RV FAC (19.2%), RV S` (12.7%) suggesting a rise in systolic function of right heart. Mean pulmonary arterial pressure (mean PAP) increased post-dive from 13.3 mmHg to maximally 23.5 mmHg (P = .002), indicating increased RV afterload. Our results demonstrated that single dive with significant bubble load lead to increase in systolic function and longitudinal strain of the right heart in parallel with increase in mean PAP.

Propulsion of blood through the right heart circulatory system

Venous return, the right heart function and the pulmonary circulation is an integrated functional unit. The right ventricle is particularly load sensitive, and will be influenced directly by the venous and pulmonary physiology. In this paper we present important physiological principles that govern the diagnosis and treatment of dysfunctions affecting the return of blood to the heart and the transfer of the cardiac output from the right to the left side. We do evaluate both basic science and the clinical literature pointing to practical aspects of physiological knowledge.

Role of Two-Dimensional Speckle-Tracking Echocardiography Strain in the Assessment of Right Ventricular Systolic Function and Comparison with Conventional Parameters

Despite the already well-known role the right side of the heart plays in many diseases, right ventricular (RV) function has only recently been carefully considered. Echocardiography is the first-line diagnostic technique for the assessment of the right ventricle and right atrium, whereas cardiac magnetic resonance is considered the gold standard but is limited by cost and availability. According to the current guidelines, systolic RV function should be assessed by several conventional measurements, but the efficacy of these parameters as diagnostic and prognostic tools has been questioned by many authors. The development in recent years of myocardial deformation imaging techniques and their application to the right heart chambers has allowed deeper evaluation of the importance of RV function in the pathophysiology of a large number of cardiovascular conditions, but the real value of this new tool has not been completely clarified. The aim of this review is to provide a wide and careful analysis of findings available in the literature about the assessment of RV systolic function by strain measurements, comparing them with conventional parameters and evaluating their role in several clinical settings.

Right ventricular strain in heart failure: Clinical perspective

The number of studies demonstrating the importance of right ventricular remodelling in a wide range of cardiovascular diseases has increased in the past two decades. Speckle-tracking imaging provides new variables that give comprehensive information about right ventricular function and mechanics. In this review, we summarize current knowledge of right ventricular mechanics in heart failure with reduced ejection fraction and preserved ejection fraction. We searched PubMed, MEDLINE, Ovid and Embase databases for studies published from January 2000 to December 2016 in the English language using the following keywords: "right ventricle"; "strain"; "speckle tracking"; "heart failure with reduced ejection fraction"; and "heart failure with preserved ejection fraction". Investigations showed that right ventricular dysfunction is associated with higher cardiovascular and overall mortality in patients with heart failure, irrespective of ejection fraction. The number of studies investigating right ventricular strain in patients with heart failure with reduced ejection fraction is constantly increasing, whereas data on right ventricular mechanics in patients with heart failure with preserved ejection fraction are limited. Given the high feasibility, accuracy and clinical implications of right ventricular strain in the population with heart failure, it is of great importance to try to include the evaluation of right ventricular strain as a regular part of each echocardiographic examination in patients with heart failure. However, further investigations are necessary to establish right ventricular strain as a standard variable for decision-making.

Longitudinal strain of systemic right ventricle correlates with exercise capacity in adult with transposition of the great arteries after atrial switch

BACKGROUND

Systemic right ventricle (sRV) dysfunction in d-transposition of the great arteries following atrial switch (d-TGA) is associated with increased mortality. We aimed to characterize maladaptive sRV mechanisms in d-TGA patients, analyzing relation of echocardiographic parameters of sRV systolic function to objective measurements of exercise capacity.

METHODS

Forty-seven adult patients with d-TGA and atrial switch (mean age 31.6±4.2years) underwent conventional echocardiography, bidimensional strain (2D-strain), cardiac magnetic resonance (CMR) imaging and cardiopulmonary exercise evaluation on the same day. Those with median peak oxygen uptake (VO2)>64.5% (n=23) constituted group A, those with VO2≤64.5% (n=24) constituted group B and 23 healthy age and gender matched subjects constituted the control group.

RESULTS

In group A, global longitudinal peak systolic 2D-strain (GLS) of sRV was significantly reduced compared to GLS of normal RV and LV in the healthy control group (p<0.01), however peak longitudinal 2D strain was similar at basal and mid-segment of sRV free wall than normal LV. In group B, GLS was significantly reduced compared to group A (-10.9±2.9% vs -13.1±2.3%, p<0.05), mostly due to significant decrease of interventricular septum longitudinal strain. Other echocardiographic systolic parameters were not significantly different between groups A and B. Only sRV GLS showed significant correlation with functional capacity as measured by VO2 (r=0.42, p<0.01), while CMR RVEF did not.

CONCLUSION

GLS of sRV predicts functional capacity and may be more sensitive than CMR RVEF in detecting early myocardial damage of sRV in patients with d-TGA and atrial switch.

The Right Ventricular Function After Left Ventricular Assist Device (RVF-LVAD) study: rationale and preliminary results

AIMS

Despite improved outcomes and lower right ventricular failure (RVF) rates with continuous-flow left ventricular assist devices (LVADs), RVF still occurs in 20-40% of LVAD recipients and leads to worse clinical and patient-centred outcomes and higher utilization of healthcare resources. Preoperative quantification of RV function with echocardiography has only recently been considered for RVF prediction, and RV mechanics have not been prospectively evaluated.

METHODS AND RESULTS

In this single-centre prospective cohort study, we plan to enroll a total of 120 LVAD candidates to evaluate standard and mechanics-based echocardiographic measures of RV function, obtained within 7 days of planned LVAD surgery, for prediction of (i) RVF within 90 days; (ii) quality of life (QoL) at 90 days; and (iii) RV function recovery at 90 days post-LVAD. Our primary hypothesis is that an RV echocardiographic score will predict RVF with clinically relevant discrimination (C >0.85) and positive and negative predictive values (>80%). Our secondary hypothesis is that the RV score will predict QoL and RV recovery by 90 days. We expect that RV mechanics will provide incremental prognostic information for these outcomes. The preliminary results of an interim analysis are encouraging.

CONCLUSION

The results of this study may help improve LVAD outcomes and reduce resource utilization by facilitating shared decision-making and selection for LVAD implantation, provide insights into RV function recovery, and potentially inform reassessment of LVAD timing in patients at high risk for RVF.

Impaired Global Right Ventricular Longitudinal Strain Predicts Long-Term Adverse Outcomes in Patients with Pulmonary Arterial Hypertension

Background

New 2-dimensional strain echocardiography enables quantification of right ventricular (RV) mechanics by assessing global longitudinal strain of RV (GLSRV) in patients with pulmonary arterial hypertension (PAH). However, the prognostic significance of impaired GLSRV is unclear in these patients.

Methods

Comprehensive echocardiography was performed in 51 consecutive PAH patients without atrial fibrillation (40 females, 48 ± 14 years old) with long-term follow-up. GLSRV was measured with off-line with velocity vector imaging (VVI, Siemens Medical System, Mountain View, CA, USA).

Results

GLSRV showed significant correlation with RV fractional area change (r = -0.606, p < 0.001), tricuspid annular plane systolic excursion (r = -0.579, p < 0.001), and RV Tei index (r = 0.590, p < 0.001). It showed significant correlations with pulmonary vascular resistance (r = 0.469, p = 0.001) and B-natriuretic peptide concentration (r = 0.351, p = 0.012). During a clinical followup time (45 ± 15 months), 20 patients experienced one or more adverse events (12 death, 2 lung transplantation, and 15 heart failure hospitalization). After multivariate analysis, age [hazard ratio (HR) = 2.343, p = 0.040] and GLSRV (HR = 2.122, p = 0.040) were associated with adverse clinical events. Age (HR = 3.200, p = 0.016) and GLSRV (HR = 2.090, p = 0.042) were also significant predictors of death. Impaired GLSRV (≥ -15.5%) was associated with lower event-free survival (HR = 4.906, p = 0.001) and increased mortality (HR = 8.842, p = 0.005).

Conclusion

GLSRV by VVI showed significant correlations with conventional echocardiographic parameters indicating RV systolic function. Lower GLSRV (≥ -15.5%) was significantly associated with presence of adverse clinical events and deaths in PAH patients.

Right ventricular dysfunction in children and adolescents conceived by assisted reproductive technologies

Assisted reproductive technologies (ART) predispose the offspring to vascular dysfunction, arterial hypertension, and hypoxic pulmonary hypertension. Recently, cardiac remodeling and dysfunction during fetal and early postnatal life have been reported in offspring of ART, but it is not known whether these cardiac alterations persist later in life and whether confounding factors contribute to this problem. We, therefore, assessed cardiac function and pulmonary artery pressure by echocardiography in 54 healthy children conceived by ART (mean age 11.5 ± 2.4 yr) and 54 age-matched (12.2 ± 2.3 yr) and sex-matched control children. Because ART is often associated with low birth weight and prematurity, two potential confounders associated with cardiac dysfunction, only singletons born with normal birth weight at term were studied. Moreover, because cardiac remodeling in infants conceived by ART was observed in utero, a situation associated with increased right heart load, we also assessed cardiac function during high-altitude exposure, a condition associated with hypoxic pulmonary hypertension-induced right ventricular overload. We found that, while at low altitude cardiac morphometry and function was not different between children conceived by ART and control children, under the stressful conditions of high-altitude-induced pressure overload and hypoxia, larger right ventricular end-diastolic area and diastolic dysfunction (evidenced by lower E-wave tissue Doppler velocity and A-wave tissue Doppler velocity of the lateral tricuspid annulus) were detectable in children and adolescents conceived by ART. In conclusion, right ventricular dysfunction persists in children and adolescents conceived by ART. These cardiac alterations appear to be related to ART per se rather than to low birth weight or prematurity.

Relationship between Right Ventricular Longitudinal Strain, Invasive Hemodynamics, and Functional Assessment in Pulmonary Arterial Hypertension

BACKGROUND AND OBJECTIVES

Right ventricular longitudinal strain (RVLS) is a new parameter of RV function. We evaluated the relationship of RVLS by speckle-tracking echocardiography with functional and invasive parameters in pulmonary arterial hypertension (PAH) patients.

SUBJECTS AND METHODS

Thirty four patients with World Health Organization group 1 PAH (29 females, mean age 45±13 years old). RVLS were analyzed with velocity vector imaging.

RESULTS

Patients with advanced symptoms {New York Heart Association (NYHA) functional class III/IV} had impaired RVLS in global RV (RVLSglobal, -17±5 vs. -12±3%, p<0.01) and RV free wall (RVLSFW, -19±5 vs. -14±4%, p<0.01 to NYHA class I/II). Baseline RVLSglobal and RVLSFW showed significant correlation with 6-minute walking distance (r=-0.54 and r=-0.57, p<0.01 respectively) and logarithmic transformation of brain natriuretic peptide concentration (r=0.65 and r=0.65, p<0.01, respectively). These revealed significant correlations with cardiac index (r=-0.50 and r=-0.47, p<0.01, respectively) and pulmonary vascular resistance (PVR, r=0.45 and r=0.45, p=0.01, respectively). During a median follow-up of 33 months, 25 patients (74%) had follow-up examinations. Mean pulmonary arterial pressure (mPAP, 54±13 to 46±16 mmHg, p=0.03) and PVR (11±5 to 6±2 wood units, p<0.01) were significantly decreased with pulmonary vasodilator treatment. RVLSglobal (-12±5 to -16±5%, p<0.01) and RVLSFW (-14±5 to -18±5%, p<0.01) were significantly improved. The decrease of mPAP was significantly correlated with improvement of RVLSglobal (r=0.45, p<0.01) and RVLSFW (r=0.43, p<0.01). The PVR change demonstrated significant correlation with improvement of RVLSglobal (r=0.40, p<0.01).

CONCLUSION

RVLS correlates with functional and invasive hemodynamic parameters in PAH patients. Decrease of mPAP and PVR as a result of treatment was associated with improvement of RVLS.

Novel technologies and devices for monitoring and treating pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature associated with significant morbidity and mortality. Despite significant advances in the past 2 decades with the development of pharmacological therapies to target key molecular pathways of PAH, there remains an ongoing need for novel technologies and devices for diagnosis, monitoring, and treatment to improve PAH outcomes. The advent of sophisticated imaging tools, including cardiac magnetic resonance imaging, positron emission tomography, and speckle tracking echocardiography, offer novel opportunities for advanced, noninvasive assessment of right ventricular function, the most powerful predictor of death in patients with PAH. Noninvasive cardiac output monitors and implantable hemodynamic sensors are among the additional promising novel technologies that might offer daily access to hemodynamic data to influence clinical decision-making and potentially improve outcomes. Percutaneous interventional therapeutics might offer a nonpharmacological treatment option in select patients with PAH, ranging from the percutaneous creation of right to left shunts, pulmonary artery denervation, and right ventricular pacing. Finally, mechanical circulatory support with durable ventricular assist devices offers hope to one day provide a realistic strategy to treat life-threatening right ventricular failure in PAH. Future clinical trials and carefully designed prospective observational studies will be needed to evaluate the full potential of many of these novel devices and technologies for monitoring and treating PAH.

Impaired RV global longitudinal strain is associated with poor long-term clinical outcomes in patients with acute inferior STEMI

OBJECTIVES

The aim of this study was to assess the long-term prognostic value of the global longitudinal strain of the right ventricle (GLSRV) in patients with inferior ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI).

BACKGROUND

RV systolic dysfunction is an important prognostic factor in patients with inferior STEMI.

METHODS

All consecutive inferior STEMI patients were included from January 2005 to December 2013. RV systolic function was analyzed with GLSRV using velocity vector imaging (Siemens, Mountain View, California), as well as conventional echocardiographic indices, including right ventricular fractional area change (RVFAC) and tricuspid annular plane systolic excursion (TAPSE).

RESULTS

We analyzed a total of 282 consecutive inferior STEMI patients (212 men, age 63 ± 13 years) treated with primary PCI. During the follow-up period (54 ± 35 months), 59 patients (21%) had 1 or more major adverse cardiovascular event (MACE) (43 deaths, 7 nonfatal MI, 4 target vessel revascularization, and 6 heart failure admission). The best cutoff value of GLSRV for the prediction of MACE was ≥-15.5% (area under the curve = 0.742, p < 0.001) with a sensitivity of 73% and a specificity of 65%. GLSRV showed better sensitivity and specificity than RVFAC and TAPSE. After multivariate analysis, GLSRV showed a higher c-statistic value (0.770) than RVFAC (0.749) and TAPSE (0.751) in addition to age, Killip class, troponin-I, left ventricular (LV) ejection fraction and RV infarction. Patients with GLSRV≥-15.5% showed significantly lower 5-year survival rate (74 ± 5% vs. 89 ± 3%, p < 0.001) and lower MACE-free survival rate (64 ± 5% vs. 87 ± 3%, p < 0.001) than the control group.

CONCLUSIONS

Because GLSRV showed additive predictive value to age and LV function, it can be the strongest parameter of RV systolic function evaluating the prognosis after PCI for acute inferior STEMI particularly in patients with preserved LV function.

Usefulness of right ventricular basal free wall strain by two-dimensional speckle tracking echocardiography in patients with chronic thromboembolic pulmonary hypertension

Recently two-dimensional (2D) speckle tracking echocardiography (STE) derived from right ventricular (RV) free wall has been shown to be a very useful tool for the estimation of RV performance. The purpose of this study was to examine whether RV basal free wall strain can detect increased mean pulmonary arterial pressure (mPAP) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). We investigated a total of 126 patients with CTEPH (mean age, 56 ± 12 years). They underwent echocardiography and right heart catheter examination. 2D STE-derived longitudinal strain was measured by placing 2 regions of interests (ROIs) on the RV basal free wall in RV-focused apical 4-chamber view. Peak strain (RV-PS) was acquired between the 2 ROIs. Conventional echocardiographic RV parameters (RV fractional area change, RV myocardial performance index, tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity, and tricuspid regurgitant pressure gradient) were evaluated as well. Right heart catheterization was performed on the day following of echocardiographic evaluation. Among RV echo parameters, RV-PS showed the best correlation with mPAP (r = 0.75, P < 0.0001). Receiver operating characteristic analysis revealed that a cut-off value of RV-PS -20.8% could detect mPAP ≧ 25 mmHg (sensitivity 78%, specificity 93%, area under the curve 0.90, P < 0.001). RV basal free wall strain was a useful tool for the non-invasive detection of increased mPAP in patients with CTEPH.

Two-dimensional global longitudinal strain rate is a preload independent index of systemic right ventricular contractility in hypoplastic left heart syndrome patients after Fontan operation

BACKGROUND

Assessment of systemic right ventricular (RV) function in patients with hypoplastic left heart syndrome is important during long-term follow-up after Fontan repair. Traditional echocardiographic parameters to evaluate systolic ventricular function are affected by loading conditions. The only generally accepted load-independent parameter of systolic function, end systolic elastance (Ees), requires invasive catheterization. Therefore, we sought to determine if parameters obtained by 2-dimensional speckle tracking (2DST) were affected by acute changes in preload and correlated with catheterization-derived indices of RV contractility in hypoplastic left heart syndrome patients after Fontan palliation.

METHODS AND RESULTS

Fifty-two patients with hypoplastic left heart syndrome (median age, 6.6; range 2.9-22.2 years) were prospectively enrolled to have echocardiography and conductance catheter studies performed simultaneously. We compared traditional echo, 2-dimensional speckle tracking and catheterization-derived parameters during different states of preload at baseline and during dobutamine infusion. Global longitudinal strain (S) showed a tendency to decrease with preload reduction, whereas global longitudinal strain rate (SR) did not change (S: -17.7 ± 3.4% versus -16.9 ± 3.8%, P=0.08; SR: -1.30 ± 0.29 versus -1.34 ± 0.34 s(-1), P=0.3). S did not change with dobutamine infusion (-17.7 ± 3.4% versus -18.4 ± 3.9%, P=0.24), whereas SR increased significantly (-1.30 ± 0.29 versus -2.26 ± 0.49 s(-1), P<0.001). RV Ees correlated with SR (rs= -0.47, P<0.001), but not with S (rs=0.07, P=0.5) or other echocardiographic parameters.

CONCLUSIONS

In contrast to S, SR was not affected by preload and correlated with Ees of the systemic RV. SR may be a useful noninvasive surrogate of RV contractility and suitable for follow-up of patients with hypoplastic left heart syndrome after Fontan palliation.

Validation of global longitudinal strain and strain rate as reliable markers of right ventricular dysfunction: comparison with cardiac magnetic resonance and outcome

Background

Right ventricular (RV) dysfunction in ischemic cardiomyopathy (ICM) is associated with poor prognosis, but RV assessment by conventional echocardiography remains difficult. We sought to validate RV global longitudinal strain (RVGLS) and global longitudinal strain rate (RVGLSR) against cardiac magnetic resonance (CMR) and outcome in ICM.

Methods

In 57 patients (43 men, 64 ± 12 years) with ICM who underwent conventional and strain echocardiography and CMR, RVGLS and RVGLSR were measured off-line. RV dysfunction was determined by CMR [RV ejection fraction (RVEF) < 50%]. Patients were followed over 15 ± 9 months for a composite of death and hospitalization for worsening heart failure.

Results

RVGLS showed significant correlations with CMR RVEF (r = -0.797, p < 0.01), RV fractional area change (RVFAC, r = -0.530, p < 0.01), and tricuspid annular plane systolic excursion (TAPSE, r = -0.547, p < 0.01). RVGLSR showed significant correlations between CMR RVEF (r = -0.668, p < 0.01), RVFAC (r = -0.394, p < 0.01), and TAPSE (r = -0.435, p < 0.01). RVGLS and RVGLSR showed significant correlations with pulmonary vascular resistance (r = 0.527 and r = 0.500, p < 0.01, respectively). The best cutoff value of RVGLS for detection of RV dysfunction was -15.4% [areas under the curve (AUC) = 0.955, p < 0.01] with a sensitivity of 81% and specificity 95%. The best cutoff value for RVGLSR was -0.94 s^-1 (AUC = 0.871, p < 0.01), sensitivity 72%, specificity 86%. During follow-up, there were 12 adverse events. In Cox-proportional hazard regression analysis, impaired RVGLS [hazard ratio (HR) = 5.46, p = 0.030] and impaired RVGLSR (HR = 3.95, p = 0.044) were associated with adverse clinical outcome.

Conclusion

Compared with conventional echocardiographic parameters, RVGLS and RVGLSR correlate better with CMR RVEF and outcome.

Right ventricular cardiomyopathies: a multidisciplinary approach to diagnosis

The physiological importance of the right ventricle (RV) has been underestimated over the past years. Finally in the early 1950s through the 1970s, cardiac surgeons recognized the importance of RV function. Since then, the importance of RV function has been recognized in many acquired cardiac heart disease. RV can be mainly or together with left ventricle (LV) affected by inherited or acquired cardiomyopathy. In fact, RV morphological and functional remodeling occurs more common during cardiomyopathies than in ischemic cardiomyopathies and more closely parallels LV dysfunction. Moreover, there are some cardiomyopathy subtypes showing a predominant or exclusive involvement of the RV, and they are probably less known by cardiologists. The clinical approach to right ventricular cardiomyopathies is often challenging. Imaging is the first step to raise the suspicion and to guide the diagnostic process. In the differential diagnosis, cardiologists should consider athlete's heart, congenital heart diseases, multisystemic disorders, and inherited arrhythmias. However, a multiparametric and multidisciplinary approach, involving cardiologists, experts in imaging, geneticists, and pathologists with a specific expertise in these heart muscle disorders is required.