Relation of right ventricular free wall mechanical delay to right ventricular dysfunction as determined by tissue Doppler imaging

Right ventricular dyssynchrony predicts outcome in pulmonary arterial hypertension when assessed in multiple cardiac magnetic resonance views

BACKGROUND

Right ventricular (RV) dyssynchrony or post systolic contraction (PSC) causes inefficient pumping and has not been investigated as a prognostic marker in pulmonary arterial hypertension (PAH). The objective was to investigate if RV dyssynchrony and PSC are prognostic markers of transplantation-free survival in PAH and if multiple RV views improve prognostication.

METHODS

Patients with PAH undergoing cardiovascular magnetic resonance between 2003 and 2021 were included. For strain analysis, endocardial end-diastolic RV contours were delineated in RV three-chamber (RV3ch), four-chamber (4ch), and midventricular short-axis (SAX) slice. RV dyssynchrony was defined as the standard deviation of time to peak strain in the walls from one (4ch), two (4ch and SAX), or three views (4ch, SAX, and RV3ch). PSC was defined as peak strain occurring after pulmonary valve closure. Outcome was defined as death or lung transplantation.

RESULTS

One hundred and one patients (58 ± 19 years, 66% (67/101) women) were included. Median follow-up was 37 [51] months. There were 60 events (55 deaths and 5 lung transplantations). Outcome was associated with RV dyssynchrony from three views and with RV strain in 4ch. An increase in RV dyssynchrony-in three views-by 1% was associated with a 10% increased risk of lung transplantation or death. There was no association between outcome and RV dyssynchrony in one or two views nor with PSC.

CONCLUSION

RV dyssynchrony in three views was associated with outcome in PAH, whereas assessing dyssynchrony from one or two views and PSC was not. This implies that assessment of multiple instead of single RV views could potentially be used for prognostication in PAH.

Right Ventricular Remodeling Assessed by MRI in Duchenne Muscular Dystrophy

BACKGROUND

In Duchenne muscular dystrophy (DMD), the right ventricle (RV) tends to be relatively well preserved, but characterization remains difficult due to its complex architecture. Tissue phase mapping (TPM) is a phase contrast cine MRI technique that allows for multidirectional assessment of myocardial velocities.

PURPOSE

To use TPM to elucidate relationships between myocardial structure, function, and clinical variables in DMD.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 20 patients with muscular dystrophy (median age: 16 years); 18 age-matched normal controls (median age: 15 years).

FIELD STRENGTH/SEQUENCE

Three-directional velocity encoded cine gradient echo sequence (TPM) at 1.5 T, balanced steady-state free procession (bSSFP), T1 mapping with extracellular volume (ECV), and late gadolinium enhancement (LGE).

ASSESSMENT

TPM in basal, mid, and apical short-axis planes was performed as part of a standard MRI study with collection of clinical data. Radial, circumferential, and longitudinal velocities (Vr, Vφ, and Vz, respectively) and corresponding time to peak (TTP) velocities were quantified from TPM and used to calculate RV twist as well as intraventricular and interventricular dyssynchrony. The correlations between TPM velocities, myocardial structure/function, and clinical variables were assessed.

STATISTICAL TEST

Unpaired t-test, Wilcoxon rank-sum test, Bland-Altman analyses were used for comparisons between DMD patients and controls and between DMD subgroups. Pearson's test was used for correlations (r). Significance level: P < 0.05.

RESULTS

Compared to controls, DMD patients had preserved RV ejection fraction (RVEF 53% ± 8%) but significantly increased interventricular dyssynchrony (Vφ: 0.49 ± 0.21 vs. 0.72 ± 0.17). Within the DMD cohort, RV dyssynchrony significantly increased with lower LV ejection fraction (intraventricular Vr and Vz: r = -0.49; interventricular Vz: r = 0.48). In addition, RV intraventricular dyssynchrony significantly increased with older age (Vz: r = 0.67).

DATA CONCLUSION

RV remodeling in DMD occurs in the context of preserved RVEF. Within DMD, this abnormal RV deformation is associated with older age and decreased LVEF.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 2.

Right Ventricular Dyssynchrony in Patients With Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Arterial Hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH) are characterized by elevated pulmonary arterial pressure resulting in right heart failure. Right ventricular (RV) dyssynchrony may be associated with early-stage RV dysfunction; however, the differences in RV dyssynchrony between CTEPH and PAH and the factors contributing to RV dyssynchrony remain unclear.

METHODS AND RESULTS

Forty-four patients (CTEPH, 26; PAH, 18) were enrolled in this study. RV dyssynchrony was assessed by determining the standard deviation of the intervals from the peak QRS to peak systolic strain for 6 segments of the RV free and septal wall by using 2-dimensional speckle-tracking echocardiography (RV-6SD). The RV-6SD, pulmonary hemodynamics, echocardiographic findings, and patient demographics in CTEPH and PAH patients were compared and their correlations with RV-6SD were investigated. CTEPH patients were older and had significantly higher pulse pressure of the pulmonary artery (PP), tricuspid valve regurgitation pressure gradient, and RV-6SD, and lower pulmonary arterial compliance (PAC), despite showing comparable pulmonary arterial pressures. Age-adjusted multiple logistic analysis showed that RV-6SD and PAC were predictors of CTEPH rather than PAH. RV-SD6 was positively correlated with PP and RV dimension and negatively correlated with PAC.

CONCLUSIONS

CTEPH patients showed more evident RV dyssynchrony than PAH patients. Low PAC and a widened PP may delay RV free wall motion and cause RV dyssynchrony.

Strain generation and right ventricular systolic function: The sum of all its parts

BACKGROUND

Speckle-tracking echocardiography (STE) has provided a reliable means to enhance characterization and quantification of global right ventricular (RV) systolic function. The use of Automated Functional Imaging (AFI) software has been previously used to quantify RV longitudinal peak global strain (PGS) values during two-dimensional (2D) transthoracic echocardiographic examinations. However, there is a paucity of data regarding relative strain contribution of each individual regional segments when compared with global strain assessment. Consequently, our goal was to use AFI STE to examine the strain contribution of each regional segment when assessing RV function.

METHODS

A retrospective analysis was performed on 107 patients that met our study criteria to correlate 2D TTE measures of RV systolic function to both RV AFI STE longitudinal peak global strain (PGS) and each individual regional RV free wall (RVFw) and inter-ventricular septum (IS) strain values.

RESULTS

We found that TTE variables of RV systolic function only correlated with PGS (RVFAC; P < .0001, TAPSE; P < .0001, and TA TDI S'; P < .0001) but none of the six individual regional AFI strain values. When PGS was not included in the multivariate analysis, only the mid RVFw and mid IS strain regions correlated with measures of RV systolic function.

CONCLUSIONS

Regional differences do exist with regards to strain generation along the RVFw and IS. These differences could be physiologically and anatomically explained based on our current understanding of RV muscle fiber arrangement. Further research is now needed to better characterize RV function in different clinical entities.

Impact of Right Ventricular Function on Left Ventricular Torsion and Ventricular Deformations in Pulmonary Artery Hypertension Patients

INTRODUCTION

Ventricular interdependence in pulmonary arterial hypertension (PAH) by the use of most recent echocardiographic techniques is still rare. The current case-controlled study aims to assess left ventricular (LV) torsion in patients with PAH.

METHODS

The study included 42 cases of moderate to severe PAH and 42 age and gender-matched healthy controls between March 2016 and January 2018. All the patients and controls undergo routine practice echocardiography using the Vivid 7-echocardiography (2.5MHz transducer) system.

RESULTS

The LV twisting parameters, peak basal rotation, peak apical rotation, and twist were similar among both cases and controls, however, LV torsion was significantly (p=0.04) impacted. Right ventricular (RV) longitudinal deformation was clinically significant in the cases compared to controls: RV systolic strain imaging (p=0.001, 95% CI-9.75 to -2.65), RV systolic strain rate (p=0.01, 95% CI-0.99 to -0.09), and RV late diastolic strain rate (p=0.01, 95% CI-0.64 to -0.85). Although PAH did not impact longitudinal LV deformations significantly. At basal level circumferential strain and strain rate were significantly impacted (p=0.005, 95% CI-4.38 to -0.70; p=0.004, 95% CI-0.35 to -0.07) in the PAH group, while the radial strain was preserved. All RV echocardiographic parameters and LV end-diastolic dimension, LV end-systolic volume in the PAH were affected significantly (p=0.002, 95% CI-19.91 to -4.46; p=0.01, 95% CI-8.44 to -2.77). However, only a weak correlation (p=0.05, r =-0.20) was found between tricuspid annular plane systolic excursion and LV Tei index.

CONCLUSION

RV pressure overload directly affects RV longitudinal systolic deformation further influences the interventricular septal and LV geometry, which impaired LV torsion.

The influence of increased venous return on right ventricular dyssynchrony during acute and sustained hypoxaemia

NEW FINDINGS

What is the central question of this study? Right ventricular dyssynchrony is a marker of function that is elevated in healthy individuals exposed to acute hypoxia, but does it remain elevated during sustained exposure to high altitude hypoxia, and can it be normalised by augmenting venous return? What is the main finding and its importance? For the first time it is demonstrated that (i) increasing venous return in acute hypoxia restores the synchrony of right ventricular contraction and (ii) dyssynchrony is evident after acclimatisation to high altitude, and remains sensitive to changes in venous return. Therefore, the interpretation of right ventricular dyssynchrony requires consideration the prevailing haemodynamic state.

ABSTRACT

Regional heterogeneity in timing of right ventricular (RV) contraction (RV dyssynchrony; RVD) occurs when pulmonary artery systolic pressure (PASP) is increased during acute hypoxia. Interestingly, RVD is not observed during exercise, a stimulus that increases both PASP and venous return. Therefore, we hypothesised that RVD in healthy humans is sensitive to changes in venous return, and examined whether (i) increasing venous return in acute hypoxia lowers RVD and (ii) if RVD is further exaggerated in sustained hypoxia, given increased PASP is accompanied by decreased ventricular filling at high altitude. RVD, PASP and right ventricular end-diastolic area (RVEDA) were assessed using transthoracic two-dimensional and speckle-tracking echocardiography during acute normobaric hypoxia ( F i O 2  = 0.12) and sustained exposure (5-10 days) to hypobaric hypoxia (3800 m). Venous return was augmented with lower body positive pressure at sea level (LBPP; +10 mmHg) and saline infusion at high altitude. PASP was increased in acute hypoxia (20 ± 6 vs. 28 ± 7, P < 0.001) concomitant to an increase in RVD (18 ± 7 vs. 38 ± 10, P < 0.001); however, the addition of LBPP during hypoxia decreased RVD (38 ± 0 vs. 26 ± 10, P < 0.001). Sustained hypoxia increased PASP (20 ± 4 vs. 26 ± 5, P = 0.008) and decreased RVEDA (24 ± 4 vs. 21 ± 2, P = 0.042), with RVD augmented (14 ± 5 vs. 31 ± 12, P = 0.001). Saline infusion increased RVEDA (21 ± 2 vs. 23 ± 3, P = 0.008) and reduced RVD (31 ± 12 vs. 20 ± 9, P = 0.001). In summary, an increase in PASP secondary to acute and sustained exposure to hypoxia augments RVD, which can be at least partly reduced via increased venous return.

Timing and magnitude of regional right ventricular function and their relationship with early hospital mortality in patients with acute pulmonary embolism

OBJECTIVE

Right ventricular (RV) dysfunction in acute pulmonary embolism (APE) has been associated with increased mortality and morbidity. The aim of the present study was to assess the timing and magnitude of regional RV functions using speckle-tracking echocardiography (STE) and their relationship to early hospital mortality in patients with APE.

METHODS

One hundred forty-two patients were prospectively studied at the onset of an acute episode and after a median follow-up period of 30 days. Their clinical and laboratory characteristics were recorded. For all patients, conventional two-dimensional echocardiography and STE were performed within 24 h after the diagnosis of APE.

RESULTS

Twenty-eight (19.7%) patients died during the hospitalization follow-up. Patients who died during hospitalization were older and had higher high sensitivity cardiac troponin T levels, and a higher percentage of patients had simplified Pulmonary Embolism Severity Indexes. In STE analyses, they had lower RV free wall peak longitudinal systolic strain (PLSS) and higher RV peak systolic strain dispersion indexes. The time to PLSS difference between RV free wall and LV lateral was longer in patients who died during hospitalization than in those who survived, and this was an independent predictor of early hospital mortality with 85.7% sensitivity and 75.0% specificity in patients with APE.

CONCLUSION

APE was associated with RV electromechanical delay and dispersion. Electromechanical delay index might be useful to predict early hospital mortality in patients with APE.

Assessment of right ventricular function and relation to mortality after acute pulmonary embolism: A speckle tracking echocardiography-based study

PURPOSE

Right ventricular (RV) dysfunction is a common condition that is related to increased adverse outcomes in patients with acute pulmonary embolism (APE). Our aim was to assess timing and magnitude of regional RV function using speckle tracking echocardiography (STE) and to evaluate their relationship to long-term mortality in patients after APE.

METHODS

In total, 147 patients were enrolled at the onset of an APE episode and followed for 12 ± 1.1 months. For all patients, the clinical, laboratory, and echocardiography examinations were performed at the diagnosis of APE and at the end of the 1-year follow-up.

RESULTS

Of the 147 patients, 44 (29.9%) died during the 1-year follow-up after APE. The patients who died had lower RV free wall peak longitudinal systolic strains (PLSS) and left ventricular (LV) PLSS and higher RV peak systolic strain dispersion (PSSD) index which means the electromechanical dispersion when compared with the survivors. The difference in time to PLSS between the RV free wall and LV lateral wall (RVF-LVL) which means the electromechanical delay was longer in patients who died than in those who survived during follow-up, and this difference was an independent predictor of mortality at 1 year of follow-up after APE, with 86.4% sensitivity and 81.7% specificity. At the end of 1-year follow-up, the RV free wall PLSS and the LV global PLSS increased, whereas the RV PSSD index and the difference in time to PLSS between the RVF and LVL decreased.

CONCLUSIONS

Acute pulmonary embolism was associated with RV dysfunction and RV electromechanical delay and dispersion. These parameters improved at the end of 1-year follow-up. The electromechanical delay index might be a useful predictor of mortality in patients after APE.

Right Ventricular Function in Left Heart Disease

Right ventricular (RV) function is an independent prognostic factor for short- and long-term outcomes in cardiac surgical patients. Patients with mitral valve (MV) disease are at increased risk of RV dysfunction before and after MV operations. Yet RV function is not part of criteria for decision making or risk stratification in this setting. The role of MV disease in the development of pulmonary hypertension (PHTN) and the ultimate impact of PHTN on RV function have been well described. Nonetheless, there are other mechanisms by which MV disease and MV surgery affect RV performance. Research suggests that PHTN may not be the most important determinant of RV dysfunction. Both RV dysfunction and PHTN have independent prognostic significance. This review explores the unique anatomic and functional features of the RV and the pathophysiologic and prognostic implications of RV dysfunction in patients with MV disease in the perioperative period.

Right ventricular dyssynchrony during hypoxic breathing but not during exercise in healthy subjects: a speckle tracking echocardiography study

NEW FINDINGS

What is the central question of this study? Right ventricular dyssynchrony in severe pulmonary hypertension is associated with a poor prognosis. However, it has recently been observed in patients with lung or connective tissue disease and pulmonary artery pressure at the upper limits of normal. The mechanisms of right ventricular dyssynchrony in pulmonary hypertension remain uncertain. What is the main finding and its importance? Acute hypoxic breathing, but not normoxic exercise, induces an increase in right ventricular dyssynchrony detected by speckle tracking echocardiography in healthy subjects. These results add new insights into the determinants of right ventricular dyssynchrony, suggesting a role for systemic factors added to afterload in the pathophysiology of right ventricular inhomogeneity of contraction.

ABSTRACT

Pulmonary hypertension (PH) has been shown to be associated with regional inhomogeneity (or dyssynchrony) of right ventricular (RV) contraction. Right ventricular dyssynchrony is an independent predictor of decreased survival in advanced PH, but has also been reported in patients with only mildly elevated pulmonary artery pressure (PAP). The mechanisms of RV dyssynchrony in PH remain uncertain. Our aim was to evaluate RV regional function in healthy subjects during acute hypoxia and during exercise. Seventeen healthy subjects (24 ± 6 years) underwent a speckle tracking echocardiography of the RV at rest in normoxia and every 15 min during a 60 min exposure to hypoxic breathing ( F I O 2 12%). Ten of the subjects also underwent an incremental cycle ergometry in normoxia to 100 W, with the same echocardiographic measurements. Dyssynchrony was measured as the SD of the times to peak systolic strain of the four basal and mid RV segments corrected for the heart rate (RV-SD4). RV-SD4 increased during hypoxia from 12 ± 7 to 22 ± 11 ms in spite of mild increases in mean PAP (mPAP) from 15 ± 2 to 20 ± 2 mmHg and pulmonary vascular resistance (PVR) from 1.18 ± 0.15 to 1.4 ± 0.15 Wood units (WU). During exercise RV-SD4 did not significantly change (from 12 ± 6 ms to 14 ± 6 ms), while mPAP increased to 25 ± 2 mmHg and PVR was unchanged. These data show that in healthy subjects, RV contraction is inhomogeneous in hypoxia but not during exercise. Since PAP increases more during exercise, RV dyssynchrony in hypoxia may be explained by a combination of mechanical (RV afterload) and systemic (hypoxia) factors.

Longitudinal Deformation of the Right Ventricle in Hypoplastic Left Heart Syndrome: A Comparative Study of 2D-Feature Tracking Magnetic Resonance Imaging and 2D-Speckle Tracking Echocardiography

In hypoplastic left heart syndrome (HLHS), long-term outcome is closely related to right ventricular function. Echocardiography and magnetic resonance imaging (MRI) are routinely used for functional assessment. MRI 2D-tissue feature tracking (2D-FT) allows quantification of myocardial deformation but has not yet been applied to HLHS patients. We sought to investigate the feasibility of this technique and to compare the results to 2D-speckle tracking echocardiography (2D-STE). In routine MRI 2D anatomical four chamber view, cine images were recorded in 55 HLHS patients (median age 4.9 years [1.6, 17.0]). Regional and global peak systolic longitudinal strain (LS) and strain rate (LSR) were determined using 2D-FT software. Echocardiographic four chamber view was analyzed with 2D-STE. Visualization of all myocardial segments with MRI was excellent, regional, and global LS and LSR could be assessed in all data sets. In 2D-STE, 28% of apical segments could not be analyzed due to poor image quality. Agreement of 2D-FT MRI and 2D-STE was acceptable for global LS, but poor for global LSR. In MRI, regional LS was lower in the septal segments, while LSR was not different between the segments. GLS and GLSR correlated with ejection fraction (GLS: r = - 0.45 and r < 0.001, GLSR: r = - 0.34 and p = 0.01). With new post-processing options, the assessment of regional and global LS and LSR is feasible in routine MRI of HLHS patients. For LS, results were comparable with 2D-STE. The agreement was poor for LSR, which might relate to differences in temporal resolution between the two imaging modalities.

Early Assessment of Right Ventricular Function in Systemic Lupus Erythematosus Patients using Strain and Strain Rate Imaging

Background

Right ventricular function is a crucial factor of the prognosis of systemic lupus erythematosus (SLE).

Objectives

To evaluate the right ventricular function in SLE patients with different degrees of pulmonary hypertension (PH) by strain and strain rate imaging.

Methods

A total of 102 SLE patients and 30 healthy volunteers were studied between October 2015 and May 2016. Patients were divided into three groups according to pulmonary artery systolic pressure (PASP) estimated by echocardiography: group control (A); PASP ≤ 30 mmHg (group B, n = 37); PASP 30-50 mmHg (mild PH; group C, n = 34); and PASP ≥ 50 mmHg (moderate-to-severe PH; group D, n = 31). Longitudinal peak systolic strain (ε) and strain rate (SR), including systolic strain rate (SRs), early diastolic strain rate (SRe) and late diastolic strain rate (SRa) were measured in the basal, middle and apical segments of the right ventricular free wall in participants by two-dimensional speckle tracking echocardiography (2D-STE) from the apical four-chamber view. A p < 0.05 was set for statistical significance.

Results

The parameters of ε, SRs, SRe, and SRa were significantly decreased in groups C and D compared with groups A and B. The ε of each segments was significantly lower in group D than in group C, while there were no differences in SRs, SRe and SRa between groups C and D.

Conclusions

Strain and strain rate imaging could early detect the right ventricular dysfunction in SLE patients with PH, and provide important value for clinical therapy and prognosis of these patients.

Right ventricular dyssynchrony and its improvements after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

PURPOSE

Whether pathologic alterations of right ventricle (RV) in chronic obstructive pulmonary disease (COPD) affect intra- and interventricular dyssynchrony due to changes in mechanical activation of the septum and RV is unclear. The aim of this study was to determine mechanical activation and its changes after pulmonary rehabilitation program (PRP) with speckle tracking echocardiography (STE) in COPD patients.

METHODS

After the exclusion of 15 patients due to poor echogenicity and 5 patients not tolerating PRP out of 69 consecutive COPD patients undergoing PRP, the remaining 49 patients and 41 healthy subjects were enrolled. The mechanical activations of both ventricles were evaluated at admission and after PRP with STE.

RESULTS

Chronic obstructive pulmonary disease patients had intra- and interventricular dyssynchrony compared to controls. The interventricular dyssynchrony assessed by time to peak longitudinal systolic strain (PLSS) difference between RV free wall and left ventricle (LV) lateral wall and intraventricular dyssynchrony assessed by RV peak systolic strain dyssynchrony (PSSD) index were improved after PRP. In all, 18 patients were hospitalized due to symptoms of right heart failure within 1 year. The time to PLSS difference between RV free wall and LV lateral wall and RV PSSD index were independent predictors of hospitalization. Receiver operating characteristics (ROC) analysis revealed that a time to PLSS difference between RV free wall and LV lateral wall >15 ms predicted hospitalization within 1 year with 77.8% sensitivity and 64.5% specificity.

CONCLUSIONS

Chronic obstructive pulmonary disease was associated with intra- and interventricular dyssynchrony. PRP had an important impact on the improvement of both intra-, and interventricular dyssynchrony, which might be used in predicting hospitalization within 1 year.

Right ventricular dyssynchrony and exercise capacity in idiopathic pulmonary arterial hypertension

Survival in patients with pulmonary arterial hypertension (PAH) is determined by right ventricular (RV) function adaptation to afterload. How altered RV function impacts on exercise capacity in PAH is not exactly known.

104 idiopathic PAH (IPAH) patients aged 52±14 years underwent a diagnostic right heart catheterisation, a comprehensive echocardiography including two-dimensional speckle tracking for RV dyssynchrony evaluation and a cardiopulmonary exercise test. Multivariate analyses were performed to identify independent predictors of peak oxygen uptake (peakV′O2).

A first multivariate analysis of only resting haemodynamic variables identified cardiac index, right atrial (RA) pressure and pulmonary arterial compliance as independent predictors, with low predictive capacity (r2=0.31; p<0.001). A second multivariate analysis model which considered only echocardiographic parameters but without RV dyssynchrony, identified RV fractional area change (FAC) and RA area as independent predictors with still low predictivity (r2=0.35; p<0.001). Adding RV dyssynchrony to the second model increased its predictivity (r2=0.48; p<0.001). Repetition of the three multivariate analyses in patients with preserved RVFAC confirmed that inclusion of RV dyssynchrony results in the highest predictive capability of peakV′O2(r2=0.53; p=0.001).

A comprehensive echocardiography with speckle tracking-derived assessment of the heterogeneity of RV contraction improves the prediction of aerobic exercise capacity in IPAH.

Left Ventricular Velocity of Propagation: A Useful Non-Invasive Measurement When Assessing Hemodynamic Alterations in Pulmonary Arterial Hypertension

Background

Left ventricular (LV) velocity of propagation (Vp) has been shown to be inversely related to the LV relaxation time constant. We sought to examine Vp from a group of chronic pulmonary hypertension (cPH) patients and compare these values to Vp obtained in normal individuals and patients with known LV diastolic dysfunction (LVDD).

Methods

Echo-Doppler data and Vp measurements were retrospectively collected from all patients. The studied population was divided into four groups. Group I comprised of 15 patients with normal LV diastole, group II included 27 patients with stage 1 LVDD, group III was made up of 27 patients with stage 2 LVDD, and group IV included 66 patients with cPH.

Results

In the cPH population studied, patients had smaller end-diastolic LV cavities with the highest Vp values but their early mitral inflow to Vp ratios were not different from healthy controls. In addition, Vp values and pulmonary wedge capillary pressures were significantly associated in patients with LV dysfunction or pulmonary hypertension (P < 0.01).

Conclusions

LVVp might be a useful non-invasive measurement to be routinely obtained in cPH patients as it probably not only reflects the compressive forces being exerted on the LV, known to increase Vp, but also might be quite useful for the non-invasive assessment of pulmonary capillary wedge pressures in these patients.

Regional right ventricular remodeling and function in children with idiopathic pulmonary arterial hypertension vs those with pulmonary valve stenosis: Insights into mechanics of right ventricular dysfunction

BACKGROUND

Right ventricular (RV) pressure overload in the context of pulmonary stenosis (PS) has a much better prognosis than in the context of idiopathic pulmonary arterial hypertension (iPAH), which may be related to differences in global and regional RV remodeling and systolic function. We compared RV mechanics in children with PS to those with iPAH, aiming to identify mechanisms and markers of RV dysfunction.

METHODS

Eighteen controls, 18 iPAH and 16 PS patients were retrospectively studied. Age, BSA, and sex distribution were comparable. Two-dimensional echocardiography, blood flow and tissue Doppler, and longitudinal RV deformation were analyzed. ANCOVA-including RV systolic pressure (RVSP) and length as covariates-was used to compare patient groups.

RESULTS

RV systolic pressure was higher in iPAH vs PS (96.8±25.4 vs 75.4±18.9 mm Hg, P=.011). Compared to controls, PS patients showed mild dilation (P<.01) and decreased longitudinal deformation (P<.001) at the RV apex. Compared to both PS and controls, iPAH patients showed marked spherical RV dilation (P<.001), reduced global, RV free wall and septal longitudinal deformation (iPAH -22.07%±4.35% vs controls -28.18%±1.69%; -9.98%±4.30% vs -17.45%±2.52%; P<.001) and RV postsystolic shortening (P<.001). RV transverse shortening (radial performance) was increased in PS (31.75%±10.35%; P<.001) but reduced in iPAH (-1.62%±11.11% vs controls 12.00%±7.74%; P<.001).

CONCLUSION

Children with iPAH demonstrate adverse global and regional RV remodeling and mechanics compared to those with PS. Mechanisms of RV systolic dysfunction in iPAH include decreased longitudinal deformation, decreased or absent transverse shortening, and postsystolic shortening. These markers may be useful to identify children at risk of RV failure.

Altered synchrony of right ventricular contraction in borderline pulmonary hypertension

Imaging studies have shown that pulmonary hypertension (PH) is associated with inhomogenous right ventricular (RV) regional contraction, or dyssynchrony, and that this is of prognostic relevance. This study aimed at the identification and functional significance of RV dyssynchrony in borderline PH defined by a mean pulmonary artery pressure between (mPAP) 20 and 25 mmHg. RV dyssynchrony was measured by 2-dimensional speckle tracking echocardiography in 17 patients with pulmonary arterial hypertension (PAH), 13 patients with borderline PH and 14 controls. Dyssynchrony was defined as the R-R interval-corrected standard deviation of the times to peak-systolic strain for the basal and medium segments of the RV. All the PH patients underwent a right heart catheterization. RV dyssynchrony amounted to 69 ± 34 ms in PAH, 47 ± 23 ms in borderline PH and 8 ± 6 ms in controls, all different from each other (p < 0.05). RV dyssynchrony in borderline PH was the only parameter of RV systolic dysfunction in 11 of 13 (85%) of the patients. RV dyssynchrony was accompanied by postsystolic shortening and correlated to RV fractional area change, not to mPAP or pulmonary vascular resistance. RV dyssynchrony occurs in borderline PH and may reflect early RV-arterial uncoupling.

Right heart-pulmonary circulation unit and cardiac resynchronization therapy

Clinical response to cardiac resynchronization therapy (CRT) has been known for years to be highly variable, with a spectrum of responses from no change or even deterioration of cardiac function to spectacular improvements. In the plethora of clinical, echocardiographic, biohumoral, and electrophysiological predictors of response to CRT and postimplant issues besides patient selection, the role of right ventricular (RV) function has been largely overlooked. In reviewing current evidence, we noticed conflicting results between observational studies and randomized trials not only concerning the impact of baseline RV function on CRT efficacy but also on the effects of CRT on RV size and function. Hence, we aimed to provide a critical reappraisal of current knowledge and unresolved issues on the reciprocal interactions between RV function and CRT, shifting the spotlight on the concept of right heart pulmonary circulation unit and on the clinical and prognostic significance of impaired ventricular-arterial coupling reserve. In this viewpoint, we propose that (1) CRT should not be denied to potential candidate because of "isolated" RV dysfunction and (2) assessment of baseline right heart pulmonary circulation unit and its dynamic response to pharmacological stress should be considered in future studies, as well as in the preimplant evaluation of individual candidates among other clinical factors.

Left Ventricular Diastolic Function Assessment of a Heterogeneous Cohort of Pulmonary Arterial Hypertension Patients

BACKGROUND

Pulmonary arterial hypertension (PAH) is known to trigger right ventricular (RV) remodeling that might compromise left ventricular (LV) filling due to inter-ventricular interdependence. In this study, we aimed to examine standard echocardiographic measurements of LV diastolic function in PAH patients.

METHODS

In this retrospective study, we identified clinical as well as complete echocardiographic data from 128 chronic PAH patients to fully assess LV diastolic dysfunction (LVDD) using standard recommended Doppler guidelines. Accordingly, patients were divided into three groups: LVDD 0, LVDD 1 and LVDD 2.

RESULTS

The mean age of the studied population was 57 ± 14 years with a mean pulmonary artery systolic pressure (PASP) of 55 ± 21 mm Hg. A total of 36% of the study patients had normal LV diastolic function. However, 64% had LVDD with LVDD stage 1 being the most common (48%). In terms of echocardiographic data, significant differences were found among the three LVDD groups in regards to PASP, LV end systolic and diastolic volumes, tricuspid annular plane systolic excursion, right ventricular fractional area change as well as many other tissue Doppler imaging parameters. Finally, just age and PASP were predictors of abnormal LV diastolic function (P < 0.05).

CONCLUSIONS

Impaired relaxation is a common abnormality in PAH patients. Additional studies are warranted to determine whether LVDD alters prognosis or is related to changes in the symptomatic profile of this group of patients.

Why septal motion is a marker of right ventricular failure in pulmonary arterial hypertension: mechanistic analysis using a computer model

Rapid leftward septal motion (RLSM) during early left ventricular (LV) diastole is observed in patients with pulmonary arterial hypertension (PAH). RLSM exacerbates right ventricular (RV) systolic dysfunction and impairs LV filling. Increased RV wall tension caused by increased RV afterload has been suggested to cause interventricular relaxation dyssynchrony and RLSM in PAH. Simulations using the CircAdapt computational model were used to unravel the mechanism underlying RLSM by mechanistically linking myocardial tissue and pump function. Simulations of healthy circulation and mild, moderate, and severe PAH were performed. We also assessed the effects on RLSM when PAH coexists with RV or LV contractile dysfunction. Our results showed prolonged RV shortening in PAH causing interventricular relaxation dyssynchrony and RLSM. RLSM was observed in both moderate and severe PAH. A negative transseptal pressure gradient only occurred in severe PAH, demonstrating that negative pressure gradient does not entirely explain septal motion abnormalities. PAH coexisting with RV contractile dysfunction exacerbated both interventricular relaxation dyssynchrony and RLSM. LV contractile dysfunction reduced both interventricular relaxation dyssynchrony and RLSM. In conclusion, dyssynchrony in ventricular relaxation causes RLSM in PAH. Onset of RLSM in patients with PAH appears to indicate a worsening in RV function and hence can be used as a sign of RV failure. However, altered RLSM does not necessarily imply an altered RV afterload, but it can also indicate altered interplay of RV and LV contractile function. Reduction of RLSM can result from either improved RV function or a deterioration of LV function.NEW & NOTEWORTHY A novel approach describes the mechanism underlying abnormal septal dynamics in pulmonary arterial hypertension. Change in motion is not uniquely induced by altered right ventricular afterload, but also by altered ventricular relaxation dyssynchrony. Extension or change in motion is a marker reflecting interplay between right and left ventricular contractility.

Right ventricular dyssynchrony predicts clinical outcomes in patients with pulmonary hypertension

BACKGROUND

RV dyssynchrony has been described in patients with pulmonary hypertension (PH) and is an independent predictor of clinical worsening; however, the optimal method for measuring RV dyssynchrony has not been fully established. This study aimed to investigate whether RV dyssynchrony is correlated with hemodynamics and prognosis in PH patients and to identify the best parameter for evaluating RV dyssynchrony.

METHODS

This study assessed 100 PH patients, measuring mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI) by right heart catheterization (RHC). RV strain curves were obtained using two-dimensional speckle-tracking echocardiography (2DSTE), and time from QRS onset to maximum peak longitudinal strain (T_max) or time to first peak (T_first) was measured. Difference in time between the earliest and the latest segment (TD) and standard deviation (SD) of T in 6 segments with RV apex (-SD6) and 4 segments without RV apex (-SD4) were also assessed.

RESULTS

Among all RV dyssynchrony parameters, T_max-SD6 showed the strongest correlation with RV hemodynamics such as mPAP (R²=0.27, P<0.0001) and PVR (R²=0.22, P<0.0001). Univariate and multivariate Cox proportional hazard analyses showed that T_max-SD6 significantly correlated with and independently predicted event-free survival in patients with PH.

CONCLUSIONS

RV dyssynchrony is a useful index for RV function and an independent predictor of clinical outcomes in patients with PH. In addition, the inclusion of apical motion is essential for the optimal assessment of RV dyssynchrony.

Prospective validation of right ventricular role in primary graft dysfunction after lung transplantation

Primary graft dysfunction is a significant cause of lung transplant morbidity and mortality, but its underlying mechanisms are not completely understood. The aims of the present study were: 1) to confirm that right ventricular function is a risk factor for severe primary graft dysfunction; and 2) to propose a clinical model for predicting the development of severe primary graft dysfunction.A prospective cohort study was performed over 14 months. The primary outcome was development of primary graft dysfunction grade 3. An echocardiogram was performed immediately before transplantation, measuring conventional and speckle-tracking parameters. Pulmonary artery catheter data were also measured. A classification and regression tree was made to identify prognostic models for the development of severe graft dysfunction.70 lung transplant recipients were included. Patients who developed severe primary graft dysfunction had better right ventricular function, as estimated by cardiac index (3.5±0.8 versus 2.6±0.7 L·min^-1·m^-2, p<0.01) and basal longitudinal strain (-25.7±7.3% versus -19.5±6.6%, p<0.01). Regression tree analysis provided an algorithm based on the combined use of three variables (basal longitudinal strain, pulmonary fibrosis disease and ischaemia time), allowing accurate preoperative discrimination of three distinct subgroups with low (11-20%), intermediate (54%) and high (75%) risk of severe primary graft dysfunction (area under the receiver operating characteristic curve 0.81).Better right ventricular function is a risk factor for the development of severe primary graft dysfunction. Preoperative estimation of right ventricular function could allow early identification of recipients at increased risk, who would benefit the most from careful perioperative management in order to limit pulmonary overflow.

Right Bundle Branch Block and Electromechanical Coupling of the Right Ventricle: An Echocardiographic Study

Background:

A growing body of evidence suggests that the presence of a right bundle branch block (RBBB) is a negative prognostic indicator in patients with and without preexisting heart disease. Even though electromechanical activation of the right ventricle (RV) in patients with RBBB and pulmonary hypertension (PH) has been investigated; a direct comparison of the presence of RBBB, on the duration of RV mechanical systole using echocardiography has not been studied.

Materials and Methods:

In this retrospective study, we analyzed the echocardiograms of 40 patients by measuring the magnitude and timing of tricuspid annulus plane systolic excursion (TAPSE) and tricuspid annulus systolic velocity (TA S’). Patients were selected to form four groups of ten patients based on the presence or absence of RBBB and PH to determine if RBBB has any effect on the time-to-peak of TAPSE or TA S’, which for our purposes serves as a measure of duration of RV mechanical systole.

Results:

Our results demonstrate that RBBB leads to a measurable prolongation of TAPSE and TA S’ in patients without PH. Time-to-peak of TAPSE or TA S’ was not significantly prolonged in patients with PH.

Conclusions:

The results of this pilot study show that RV mechanical systole is prolonged in patients with RBBB, and the addition of PH attenuates this change. Additional prospective studies are now required to elucidate further the electrical and mechanical dyssynchrony that occurs as a result of RBBB, and how these new echocardiographic measurements can be applied clinically to risk stratify patients with RBBB and PH.

Essential echocardiographic evaluation in patients with suspected pulmonary hypertension: an overview for the practicing physician

Prompt and accurate diagnosis of patients presenting with symptoms suggestive of pulmonary arterial hypertension (PAH) is of outmost importance as delays in identifying this clinical entity have detrimental effects on both morbidity and mortality. Initial noninvasive assessment of these patients has traditionally included a number of routine tests of which transthoracic echocardiography (TTE) has been shown to either confirm the presence of structural anomalies of the right ventricle (RV) indicative of PAH or exclude other potential causes of pulmonary hypertension (PH). Consequently, TTE has become a well-validated and readily available imaging tool not only used for this initial screening but also for routine follow-up of PH patients. Since chronic PH is known to unbalance the normal hemodynamic and mechanical homeostatic interaction between the RV and pulmonary circulation; the resulting response is that of an abnormal RV remodeling, clinically translated into progressive RV hypertrophy and dilatation. An enlarged and hypertrophied RV not only would eventually lose effective contractility but also this gradual decline in RV systolic function is the main abnormality in determining adverse clinical outcomes. Therefore, it is of outmost importance that TTE examination be comprehensive but most importantly accurate and reproducible. This review aims to highlight the most important objective measures that can be routinely employed, without added complexity, that will certainly enhance the interpretation and advance our understanding of the hemodynamic and mechanical abnormalities that PH exerts on the RV.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Investigating cardiac MRI based right ventricular contractility as a novel non-invasive metric of pulmonary arterial pressure

BACKGROUND

We test the hypothesis that cardiac magnetic resonance (CMR) imaging-based indices of four-dimensional (4D) (three dimensions (3D) + time) right ventricle (RV) function have predictive values in ascertaining invasive pulmonary arterial systolic pressure (PASP) measurements from right heart catheterization (RHC) in patients with pulmonary arterial hypertension (PAH).

METHODS

We studied five patients with idiopathic PAH and two age and sex-matched controls for RV function using a novel contractility index (CI) for amplitude and phase to peak contraction established from analysis of regional shape variation in the RV endocardium over 20 cardiac phases, segmented from CMR images in multiple orientations.

RESULTS

The amplitude of RV contractility correlated inversely with RV ejection fraction (RVEF; R² = 0.64, P = 0.03) and PASP (R² = 0.71, P = 0.02). Phase of peak RV contractility also correlated inversely to RVEF (R² = 0.499, P = 0.12) and PASP (R² = 0.66, P = 0.04).

CONCLUSIONS

RV contractility analyzed from CMR offers promising non-invasive metrics for classification of PAH, which are congruent with invasive pressure measurements.

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.

State of the art: advanced imaging of the right ventricle and pulmonary circulation in humans (2013 Grover Conference series)

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by remodeling and vasoconstriction of the pulmonary vasculature, ultimately leading to right ventricular (RV) failure and death. Recent developments in echocardiography, cardiovascular magnetic resonance imaging, computed tomography, and positron emission tomography allow advanced, noninvasive, in vivo assessment of the RV and have contributed to the identification of risk factors, prognostic factors, and monitoring of therapeutic responses in patients with PAH. Although far from reaching its future potential, these techniques have not only provided global RV assessment but also allowed evaluation of changes in cellular and molecular tissue processes, such as metabolism, oxygen balance and ischemia, angiogenesis, and apoptosis. Integrated application of these techniques could provide full insights into the different pathophysiological aspects of a failing RV in the setting of PAH. Recent advances in hybrid imaging have implemented simultaneous measurements of myocardial and vascular interactions and will be one of the most important potential future developments.

Right ventricular dyssynchrony in idiopathic pulmonary arterial hypertension: determinants and impact on pump function

BACKGROUND

Right ventricular (RV) dyssynchrony has been described in pulmonary arterial hypertension (PAH), but no evidence is available on its morphologic determinants and its effect on systolic function. The aim of this study was to evaluate the morphologic determinants of RV dyssynchrony by echocardiographic and cardiac magnetic resonance imaging and its effect on systolic function.

METHODS

In 60 consecutive idiopathic PAH (IPAH) patients with narrow QRS, RV dyssynchrony was evaluated by 2D speckle-tracking echocardiography, calculating the standard deviation of the times to peak systolic strain for the four mid-basal RV segments (RV-SD4). Patients were grouped by the median value of RV-SD4 (19 milliseconds) and compared for RV remodeling and systolic function parameters, WHO class, pulmonary hemodynamics and 6-minute walk test (6MWT).

RESULTS

Despite similar pulmonary vascular resistance and mean pulmonary arterial pressure, patients with RV-SD4 at >19 milliseconds had advanced WHO class and worse 6MWT, RV hemodynamics, RV remodeling and systolic function parameters compared with patients at ≤19 milliseconds. The morphologic determinants of RV dyssynchrony resulted RV end-diastolic area, LV diastolic eccentricity index and RV mass volume ratio (r = 0.69, r(2) = 0.47, p < 0.0001). Finally, we found a significant inverse correlation between RV mid-basal segments post-systolic shortening time and cardiac index (r = -0.64, r(2) = 0.41, p = 0.001), accounting for the significant correlation between RV-SD4 and cardiac index (r = 0.57, r(2) = 0.32, p = 0.003).

CONCLUSIONS

In IPAH with narrow QRS, RV dyssynchrony is associated with RV dilation and eccentric hypertrophy pattern, suggesting a role of segmental wall stress heterogeneity as the major determinant of mechanical delay. Post-systolic shortening, as inefficient contraction, contributes to pump dysfunction.

Impact of right ventricular dyssynchrony on left ventricular performance in patients with pulmonary hypertension

Pulmonary hypertension has been associated with right ventricular (RV) dyssynchrony which may induce left ventricular (LV) dysfunction and dyssynchrony through ventricular interdependence. The present study evaluated the influence of RV dyssynchrony on LV performance in patients with pulmonary hypertension. One hundred and seven patients with pulmonary hypertension (age 63 ± 14 years, systolic pulmonary arterial pressure 60 ± 19 mmHg) and LV ejection fraction (EF) >35% were evaluated. Ventricular dyssynchrony was assessed with speckle tracking echocardiography and defined as the standard deviation of the time to peak longitudinal strain of six segments of the RV (RV-SD) and the LV (LV-SD) in the apical 4-chamber view. Mean RV-SD and LV-SD assessed with longitudinal strain speckle tracking echocardiography were 51 ± 28 and 47 ± 21 ms, respectively. The patient population was divided according to the median RV-SD value of 49 ms. Patients with RV-SD ≥49 ms had significantly worse NYHA functional class (2.7 ± 0.7 vs. 2.3 ± 0.7, p = 0.004), RV function (tricuspid annular plane systolic excursion: 16 ± 4 vs. 19 ± 4 mm, p < 0.001), LVEF (50 ± 10 vs. 55 ± 8%, p = 0.001), and larger LV-SD (57 ± 18 vs. 36 ± 18 ms, p < 0.001). RV-SD significantly correlated with LV-SD (r = 0.55, p < 0.001) and LVEF (r = -0.23, p = 0.02). Multiple linear regression analysis showed an independent association between RV-SD and LV-SD (β = 0.35, 95%CI 0.21-0.49, p < 0.001). RV dyssynchrony is significantly associated with LV dyssynchrony and reduced LVEF in patients with pulmonary hypertension.

Septal curvature is marker of hemodynamic, anatomical, and electromechanical ventricular interdependence in patients with pulmonary arterial hypertension

AIMS

The objective of this study was to determine the factors independently associated with septal curvature in patients with pulmonary arterial hypertension (PAH).

METHODS

Eighty-five consecutive patients with PAH who had an echocardiogram and a right heart catheterization within 24 hours of each others were included in the study. Septal curvature was assessed at the mid-papillary level using the eccentricity index (EI). Marked early systolic septal anterior motion was defined as a change in EI > 0.2 between end-diastole and early systole. Inter-ventricular mechanical delay was calculated as the percent time difference between right ventricular (RV) to left ventricular (LV) end-ejection time normalized for the RR interval.

RESULTS

Average age was 45 ± 11 years and the majority of patients were women (75%). Mean right atrial pressure was 11 ± 7 mmHg, mean PAP was 52 ± 13 mmHg, relative RV area 1.8 ± 0.9, and RV fractional area change 24 ± 8%. End-diastolic EI was 1.6 ± 0.4 and systolic EI was 2.5 ± 0.8. On multivariate analysis relative pulmonary pressure, relative RV area, and inter-ventricular mechanical delay were independently associated with systolic EI (R(2) = 0.72, P < 0.001). Independent determinants of diastolic EI included relative RV area and mean PAP (R(2) = 0.69, P < 0.001). A systolic EI >1.08 differentiated patients with PAH from healthy controls with an AUC = 0.99. Patients with early systolic septal anterior motion (44% of subjects) had lower exercise capacity, more extensive ventricular remodeling, and worst ventricular function.

CONCLUSION

Septal curvature is a useful marker of structural, hemodynamic, and electromechanical ventricular interdependence in PAH.

Longitudinal strain curves in the RV free wall differ in morphology in patients with pulmonary hypertension compared to controls

BACKGROUND

Previous studies using speckle tracking-derived strain for quantification of right ventricular (RV) function in pulmonary hypertension (PHT) have focused on the magnitude of global and regional peak longitudinal systolic strains (PLSS) and systolic strain-related indices of dyssynchrony. The aim of our study was to investigate the pattern of RV contraction and relaxation with the use of the contour and timing of strain and velocity curves in PHT.

METHODS

The study population consisted of thirty-seven patients with PHT (45 ± 18 years, 16 women) and thirty-seven controls. A complete two-dimensional echo with speckle-tracking-derived longitudinal strain of the basal RV free wall and interventricular septum (IVS) was performed and the cycle length-corrected time to PLSS (SST) and time from PLSS to 50% of PLSS (systolic strain half time-SSHT) in both regions were calculated.

RESULTS

Patients with PHT had significantly reduced PLSS (-24.9 ± 2.0% vs -43.2 ± 3.0%, p<0.001) and increased SST (0.47 ± 0.02 vs 0.39 ± 0.02, p=0.043) and SSHT (0.22 ± 0.02 vs 0.16 ± 0.02, p=0.047) in the basal RV free wall compared to controls. Furthermore, peak systolic velocities were observed earlier in the cardiac cycle in both regions in patients with PHT compared to controls.

CONCLUSIONS

Longitudinal strain curves in the RV free wall reach peak values later in the cardiac cycle and return slower towards the baseline in PHT. Furthermore, peak systolic velocities are observed earlier in the cardiac cycle in both the basal RV free wall and the basal IVS. The above observations effectively illustrate changes in patterns of RV contraction and relaxation caused by PHT.