Right Ventricular Contraction Research Articles

How to assess and treat right ventricular electromechanical dyssynchrony in post-repair tetralogy of Fallot: insights from imaging, invasive studies, and computational modelling.

Right bundle branch block (RBBB) and resulting right ventricular (RV) electromechanical discoordination are thought to play a role in the disease process of subpulmonary RV dysfunction that frequently occur post-repair tetralogy of Fallot (ToF). We sought to describe this disease entity, the role of pulmonary re-valvulation, and the potential added value of RV cardiac resynchronization therapy (RV-CRT). Two patients with repaired ToF, complete RBBB, pulmonary regurgitation, and significantly decreased RV function underwent echocardiography, cardiac magnetic resonance, and an invasive study to evaluate the potential for RV-CRT as part of the management strategy. The data were used to personalize the CircAdapt model of the human heart and circulation. Resulting Digital Twins were analysed to quantify the relative effects of RV pressure and volume overload and to predict the effect of RV-CRT. Echocardiography showed components of a classic RV dyssynchrony pattern which could be reversed by RV-CRT during invasive study and resulted in acute improvement in RV systolic function. The Digital Twins confirmed a contribution of electromechanical RV dyssynchrony to RV dysfunction and suggested improvement of RV contraction efficiency after RV-CRT. The one patient who underwent successful permanent RV-CRT as part of the pulmonary re-valvulation procedure carried improvements that were in line with the predictions based on his Digital Twin. An integrative diagnostic approach to RV dysfunction, including the construction of Digital Twins may help to identify candidates for RV-CRT as part of the lifetime management of ToF and similar congenital heart lesions.

Pressure overload is associated with right ventricular dyssynchrony in heart failure with reduced ejection fraction.

The determinants and relevance of right ventricular (RV) mechanical dyssynchrony in heart failure with reduced ejection fraction (HFrEF) are poorly understood. We hypothesized that increased afterload may adversely affect the synchrony of RV contraction. A total of 148 patients with HFrEF and 36 controls underwent echocardiography, right heart catheterization, and gated single-photon emission computed tomography to measure RV chamber volumes and mechanical dyssynchrony (phase standard deviation of systolic displacement timing). Exams were repeated after preload (N=135) and afterload (N=15) modulation. Patients with HFrEF showed higher RV dyssynchrony compared with controls (40.6±17.5° vs. 27.8±9.1°, P<0.001). The magnitude of RV dyssynchrony in HFrEF correlated with larger RV and left ventricular (LV) volumes, lower RV ejection fraction (RVEF) and LV ejection fraction, reduced intrinsic contractility, increased heart rate, higher pulmonary artery (PA) load, and impaired RV-PA coupling (all P≤0.01). Low RVEF was the strongest predictor of RV dyssynchrony. Left bundle branch block (BBB) was associated with greater RV dyssynchrony than right BBB, regardless of QRS duration. RV afterload reduction by sildenafil improved RV dyssynchrony (P=0.004), whereas preload change with passive leg raise had modest effect. Patients in the highest tertiles of RV dyssynchrony had an increased risk of adverse clinical events compared with those in the lower tertile [T2/T3 vs. T1: hazard ratio 1.98 (95% confidence interval 1.20-3.24), P=0.007]. RV dyssynchrony is associated with RV remodelling, dysfunction, adverse haemodynamics, and greater risk for adverse clinical events. RV dyssynchrony is mitigated by acute RV afterload reduction and could be a potential therapeutic target to improve RV performance in HFrEF.

Three-dimensional echocardiographic evaluation of longitudinal and non-longitudinal components of right ventricular contraction: results from the World Alliance of Societies of Echocardiography study.

Right ventricular (RV) functional assessment is mainly limited to its longitudinal contraction. Dedicated three-dimensional echocardiography (3DE) software enabled the separate assessment of the non-longitudinal components of RV ejection fraction (EF). The aims of this study were (i) to establish normal values for RV 3D-derived longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their relative contributions to global RVEF, (ii) to calculate 3D RV strain normal values, and (iii) to determine sex-, age-, and race-related differences in these parameters in a large group of normal subjects (WASE study). 3DE RV wide-angle datasets from 1043 prospectively enrolled healthy adult subjects were analysed to generate a 3D mesh model of the RV cavity (TomTec). Dedicated software (ReVISION) was used to analyse RV motion along the three main anatomical planes. The EF values corresponding to each plane were identified as LEF, REF, and AEF. Relative contributions were determined by dividing each EF component by the global RVEF. RV strain analysis included longitudinal, circumferential, and global area strains (GLS, GCS, and GAS, respectively). Results were categorized by sex, age (18-40, 41-65, and >65 years), and race. Absolute REF, AEF, LEF, and global RVEF were higher in women than in men (P < 0.001). With aging, both sexes exhibited a decline in all components of longitudinal shortening (P < 0.001), which was partially compensated in elderly women by an increase in radial contraction. Black subjects showed lower RVEF and GAS values compared with white and Asian subjects of the same sex (P < 0.001), and black men showed significantly higher RV radial but lower longitudinal contributions to global RVEF compared with Asian and white men. 3DE evaluation of the non-longitudinal components of RV contraction provides additional information regarding RV physiology, including sex-, age-, and race-related differences in RV contraction patterns that may prove useful in disease states involving the right ventricle.

Contraction patterns of the systemic right ventricle: a three-dimensional echocardiography study.

To investigate contraction patterns of the systemic right ventricle (SRV) in patients with transposition of great arteries (TGA) post-atrial switch operation and with congenitally corrected transposition of great arteries (ccTGA). Right ventricular (RV) volumes and ejection fraction (EF) were measured by three-dimensional echocardiography in 38 patients with the SRV (24 TGA and 14 ccTGA; mean age 45 ± 12 years, 63% male), and in 38 healthy volunteers. The RV contraction was decomposed along the longitudinal, radial, and anteroposterior directions providing longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their contributions to total right ventricular ejection fraction (LEFi, REFi, and AEFi, respectvely). SRV was significantly larger with lower systolic function compared with healthy controls. SRV EF and four-chamber longitudinal strain strongly correlated with B-type natriuretic peptide (BNP) level (Rho -0.73, P < 0.0001 and 0.70, P < 0.0001, respectively). In patients with TGA, anteroposterior component was significantly higher than longitudinal and radial components (AEF 17 ± 4.5% vs. REF 13 ± 4.9% vs. LEF 10 ± 3.3%, P < 0.0001; AEFi 0.48 ± 0.09 vs. REFi 0.38 ± 0.1 vs. LEFi 0.29 ± 0.08, P < 0.0001). In patients with ccTGA, there was no significant difference between three SRV components. AEFi was significantly higher in TGA subgroup compared with ccTGA (0.48 ± 0.09 vs. 0.36 ± 0.08, P = 0.0002). Contraction patterns of the SRV are different in TGA and ccTGA. Anteroposterior component is dominant in TGA providing compensation for impaired longitudinal and radial components, while in ccTGA all components contribute equally to the total EF. SRV EF and longitudinal strain demonstrate strong correlation with BNP level and should be a part of routine echocardiographic assessment of the SRV.

Abstract 14008: Three Dimensional Surface Strain Computation From Three Dimensional Echocardiographic Images of the Right Ventricle in Idiopathic Pediatric Pulmonary Hypertension

Introduction: Right Ventricular (RV) dysfunction is the primary aspect of acute right ventricular failure, commonly realized in pulmonary arterial hypertensive (PAH) patients. As a standard clinical assessment for PAH, echocardiographic strain provides a mechanical measure of ventricular deformation during RV contraction. Current strain computation via 2D echo is limited in that imaging and strain are confined to a 2D plane, and thus the technique is unable to fully visualize the asymmetrical deformation of the RV. We believe 3D surface (3DS) strain, obtained from 3D echo (3DE) will overcome this limitation and more thoroughly evaluate myocardial mechanics. In this initial work, we hypothesize that end-systolic 3DS longitudinal and shear freewall strain group means computed from 3DE-cardiac data of the RV will differ between healthy and PAH patient groups. Methods: 3DS strain (longitudinal, circumferential, shear; principal strains, principal angle, and max shear) was computed on the RV freewall at end-systole with finite element analysis post-processing techniques from RV surface meshes obtained from 3DE from 10 normal children and 43 children with idiopathic PAH. Results: 3DS longitudinal and circumferential strain group means were significantly different (p&lt;0.0001, p=0.0002, respectively), and the 3DS shear strain mean difference approached significance (p=0.0532). Further, the 3DS max and min principal strain group means were also different (p=0.0001, p&lt;0.001, respectively), as were the max shear strain group means (p=0.0275), while the group mean difference of the principal strain angle approached significance (p=0.1055). Conclusions: These results suggest that 3DS strain is a promising approach to strain computation with potential to yield more mechanical knowledge of different segments of RV dysfunction. Future work should be directed in the evaluation of focused regional strain specific towards RV dysfunction and evaluate for prognosis.

Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation.

This study investigated patterns of right ventricular (RV) contraction by using cardiac magnetic resonance (CMR) imaging in patients undergoing transcatheter tricuspid valve repair (TTVR). The role of RV function in patients with severe tricuspid regurgitation undergoing TTVR is poorly understood. Global RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF)≤45% and longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE)<17mm on echocardiography. Patients were stratified into 3 types of RV contraction: type I, TAPSE≥17 and RVEF >45%; type II, TAPSE<17 and RVEF >45%; and type III, TAPSE<17 and RVEF≤45%. CMR feature tracking was performed to assess longitudinal and circumferential RV strain. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization. Of 79 patients (median age 79 years, 51% female), 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction. The composite outcome occurred in 22 patients (median follow-up 362days). Global RV dysfunction but not longitudinal RV dysfunction (hazard ratio: 6.62; 95% confidence interval: 2.77-15.77; and hazard ratio: 1.30; 95% confidence interval: 0.55-3.08, respectively) was associated with the composite outcome. Compared with type I RV contraction, patients with type II RV contraction exhibited increased circumferential strain, with a preservation of RVEF despite diminished longitudinal strain. Patients with type III RV contraction exhibited both diminished longitudinal and circumferential strain, resulting in an impaired RVEF. Patients with type III RV contraction showed the worst survival (P< 0.001). Global RV dysfunction is a predictor of outcomes among TTVR patients. Tricuspid regurgitation patientscan be stratified into 3 types of RV contraction, in which a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favorable outcomes.

Femoral Vein Pulsatility: What Does It Mean?

In this report, the clinical evolution of a 72-year-old patient transferred to the surgical intensive care unit after cardiac surgery is described. The presence of a pulsatile Doppler signal of the common femoral vein was noted after surgery. On postoperative day 5, diuretics in addition to a combination of inhaled epoprostenol and milrinone were associated with normalization of femoral vein pulsatility. The observations seen in peripheral venous flow reinforce the hypothesis that pulsatility of the common femoral vein represents an associated echocardiographic sign of right ventricular dysfunction and may be used to monitor systemic venous congestion. Pulsatility in the venous system may be improved by reducing volume overload and improving right ventricular function.

Study on the synchronization of biventricular beats with the control mode of left ventricular assist device

Right ventricular (RV) failure has become a deadly complication of left ventricular assist device (LVAD) implantation, for which desynchrony in bi-ventricular pulse resulting from a LVAD is among the important factor. This paper investigated how different control modes affect the synchronization of pulse between LV (left ventricular) and RV by numerical method. The numerical results showed that the systolic duration between LV and RV did not significantly differ at baseline (LVAD off and cannula clamped) (48.52% vs. 51.77%, respectively). The systolic period was significantly shorter than the RV systolic period in the continuous-flow mode (LV vs. RV: 24.38% vs. 49.16%) and the LV systolic period at baseline. The LV systolic duration was significantly shorter than the RV systolic duration in the pulse mode (LV vs. RV: 28.38% vs. 50.41%), but longer than the LV systolic duration in the continuous-flow mode. There was no significant difference between the LV and RV systolic periods in the counter-pulse mode (LV vs. RV: 43.13% vs. 49.23%). However, the LV systolic periods was shorter than the no-pump mode and much longer than the continuous-flow mode. Compared with continuous-flow and pulse mode, the reduction in rotational speed (RS) brought out by counter-pulse mode significantly corrected the duration of LV systolic phase. The shortened duration of systolic phase in the continuous-flow mode was corrected as re-synchronization in the counter-pulse mode between LV and RV. Hence, we postulated that the beneficial effects on RV function were due to re-synchronizing of RV and LV contraction. In conclusion, decreased RS delivered during the systolic phase using the counter-pulse mode holds promise for the clinical correction of desynchrony in bi-ventricular pulse resulting from a LVAD and confers a benefit on RV function.

Functional adaptation of the right ventricle to different degrees of the left ventricular systolic dysfunction in patients with left-sided heart disease: a three-dimensional echocardiography study

Abstract Funding Acknowledgements Type of funding sources: None. Background. Right ventricular (RV) systolic dysfunction in patients with left-sided heart disease is known adverse factor. However, the RV adaptation at the different degrees of left ventricular (LV) dysfunction remains to be clarified. Purpose to assess the change in RV contraction pattern in relation to LV ejection fraction (EF) in patients with left-sided heart disease. Methods. LV and RV volumes and EF were measured by 3D-echocardiography in 295 patients with left-sided heart disease (59 ± 17years, 69% male). The 3D meshmodel of the RV was postprocessed by the ReVISION software and its contraction pattern was decomposed along the longitudinal, radial and anteroposterior directions (Fig. A) providing longitudinal, radial and anteroposterior EF (LEF, REF, AEF). Relative contribution of each component to the RV systolic function was measured as the ratio between LEF, REF and AEF and global RVEF (LEFi, REFi, AEFi). Results. Patients with LV systolic dysfunction also had reduced RVEF. Relative contribution of the longitudinal and anteroposterior components decreased, while radial component increased in patients with reduced LVEF (Table). RV LEF and AEF significantly correlated with the LVEF (Rho 0.50 and 0.51, p &amp;lt; 0.0001), while the correlation between REF and LVEF was weak (Rho 0.22, p = 0.0002). There was a significant drop in LEF and AEF (Fig. B) and their relative contribution to the total RVEF (Fig. C) starting from the earlier stages of LV dysfunction. However, it was effectively compensated by significant increase in the radial RV component resulting in preservation of total RVEF in those with normal, mildly and moderately reduced LVEF (50 [46;54] vs 47 [44;52] vs 46 [42;49]%), whereas total RVEF dropped significantly only in severe LV dysfunction (30 [25;39]%; p &amp;lt; 0.0001) (Fig. D). Conclusions. The longitudinal and anteroposterior RV contraction was related to the LVEF and decreased from early stages of the LV systolic dysfunction. Increase in the radial component compensated for the loss of longitudinal and anteroposterior RV components in mild and moderate LV dysfunction to maintain total RVEF. Drop in all three components resulted in significant reduction of total RVEF in severe LV dysfunction. Characteristics of study population Overall (N = 295) LVEF≥50% (N = 166) LVEF &amp;lt; 50% (N = 129) LV EF, % 49.6 ± 14.3 59.9 ± 5.6 36.4 ± 10.9* RV EF, % 46.5 ± 9.2 49.8 ± 6.9 42.3 ± 10.0* RV LEFi 0.42 ± 0.09 0.45 ± 0.09 0.38 ± 0.09* RV REFi 0.47 ± 0.1 0.45 ± 0.1 0.50 ± 0.09* RV AEFi 0.39 ± 0.08 0.41 ± 0.08 0.37 ± 0.07* *p &amp;lt; 0.0001 Abstract Figure.

Preoperative right ventricular overwork is a major determinant of residual pulmonary arterial hypertension in patients with repaired arterial septal defect

Abstract Funding Acknowledgements Type of funding sources: None. Background The haemodynamic effect of atrial septal defect (ASD) is a chronic volume overload of the right heart and pulmonary vasculature. Pulmonary overcirculation is generally compensated for by the right ventricular (RV) and pulmonary arterial (PA) reserve. However, in a subset of patients, prolonged pulmonary overcirculation insidiously induces obstructive pulmonary vasculopathy, which results in postoperative residual pulmonary arterial hypertension (PAH) after ASD closure. Postoperative PAH is a major concern because it is closely associated with poor outcomes and impaired quality of life. However, to date, no clinically robust predictors of postoperative residual PAH have been clearly identified. Purpose This study sought to assess the haemodynamic characteristics of ASD patients in terms of mechano-energetic parameters and to identify the predictors of postoperative residual PAH in these patients. Methods A total of 120 ASD patients (age: 58 ± 17 years) and 46 normal controls were recruited. As previously reported, the simplified RV contraction pressure index (sRVCPI) was calculated as an index of RV external work by multiplying the tricuspid annular plane systolic excursion (TAPSE) by the pressure gradient between the RV and right atrium. RV- PA coupling was evaluated using TAPSE divided by PA systolic pressure as an index of the RV length-force relationship. These parameters were measured both at baseline and 6 months after ASD closure. Results As expected, baseline sRVCPI was significantly greater in patients with ASD than in controls (775 ± 298 vs. 335 ± 180 mm Hg • mm, P &amp;lt; 0.01), which indicated significant "RV overwork". As a result, RV-PA coupling in ASD patients was significantly impaired compared to that in controls (0.9 ± 0.8 vs. 3.5 ± 1.7 mm/mm Hg, P &amp;lt; 0.01). All 120 ASD patients underwent transcatheter or surgical shunt closure; 15 of them had residual PAH after closure. After 6 months, RV-PA coupling index significantly improved in patients without residual PAH, from 0.96 ± 0.81 to 1.27 ± 1.24 mm/mm Hg (P = 0.02). Furthermore, RV load was markedly reduced, with sRVCPI falling from 691 ± 258 to 434 ± 217 mm Hg • mm, P &amp;lt; 0.01). However, in patients with residual PAH, RV-PA coupling index deteriorated from 0.64 ± 0.23 to 0.53 ± 0.12 mm/mm Hg (P &amp;lt; 0.01). As a result, RV overload was not significantly relieved (sRVCPI; from 971 ± 382 to 783 ± 166 mm Hg • mm, P = 0.22). In a multivariate analysis, baseline pulmonary vascular resistance (hazard ratio 1.009; P &amp;lt; 0.01) and preoperative sRVPCI (hazard ratio 1.003; P &amp;lt; 0.01) revealed to be independent predictors of residual PAH. Conclusion In terms of mechano-energetic function, preoperative "RV overwork" can be used as a robust predictor of an impaired RV-PA relationship in ASD patients. Moreover, periodic assessment of sRVPCI may contribute to the better management for patients with unrepaired ASD. Abstract Figure.

Right ventricular mechanical pattern in patients undergoing mitral valve surgery: a predictor of post-operative dysfunction?

AimsThe PREPARE‐MVR study (PRediction of Early PostoperAtive Right vEntricular failure in Mitral Valve Replacement/Repair patients) sought to investigate the alterations of right ventricular (RV) contraction pattern in patients undergoing mitral valve replacement/repair (MVR) and to explore the associations between pre‐operative RV mechanics and early post‐operative RV dysfunction (RVD).Methods and resultsWe prospectively enrolled 42 patients (63 ± 11 years, 69% men) undergoing open‐heart MVR. Transthoracic three‐dimensional (3D) echocardiography was performed pre‐operatively, at intensive care unit discharge, and 6 months after surgery. The 3D model of the RV was reconstructed, and RV ejection fraction (RVEF) was calculated. We decomposed the motion of the ventricle to compute longitudinal ejection fraction (LEF) and radial ejection fraction (REF). Pulmonary artery catheterization was performed to monitor RV stroke work index (RVSWi). RVEF was slightly decreased after MVR [52 (50–55) vs. 51 (46–54)%; P = 0.001], whereas RV contraction pattern changed notably. Before MVR, the longitudinal shortening was the main contributor to global systolic RV function [LEF/RVEF vs. REF/RVEF; 0.53 (0.47–0.58) vs. 0.33 (0.22–0.42); P < 0.001]. Post‐operatively, the radial motion became dominant [0.33 (0.28–0.43) vs. 0.46 (0.37–0.51); P = 0.004]. However, this shift was temporary as 6 months later the two components contributed equally to global RV function [0.44 (0.38–0.50) vs. 0.41 (0.36–0.49); P = 0.775]. Pre‐operative LEF was an independent predictor of post‐operative RVD defined as RVSWi < 300 mmHg⋅mL/m2 [OR = 1.33 (95% CI: 1.08–1.77), P < 0.05].ConclusionsMVR induces a significant shift in the RV mechanical pattern. Advanced indices of RV mechanics are associated with invasively measured parameters of RV contractility and may predict post‐operative RVD.

Right ventricular transverse displacement increases following cardiac surgery: possibly compensating loss in tricuspid annular plane systolic excursion (TAPSE).

Right Ventricular (RV) output mostly derives from longitudinal shortening in normal hearts. However, following even uncomplicated cardiac surgery with preserved RV function a significant and sustained decrease in longitudinal contraction has been observed. How the RV compensates and sustains output in this setting remains unsettled. The aim of this study was to evaluate the RV contraction pattern by speckle tracking echocardiography to elucidate possible compensatory mechanisms mitigating the reduced RV longitudinal contraction after cardiac surgery. Thirty patients with normal preoperative ejection fraction and no valvulopathy underwent coronary artery bypass grafting (CABG) with the use of cardiopulmonary bypass (CPB). RV dedicated speckle tracking software measuring longitudinal and transverse displacement, as well as strain, was employed on transesophageal echocardiographic (TEE) images as part of the Right Ventricular Echocardiography in cardiac SurgEry (ReVERSE) study. Data was recorded at baseline (after anesthesia induction), immediately after CPB and upon chest closure. Tricuspid Annulus Plane Systolic Excursion (TAPSE) was reduced from 2.0 [1.6-2.5cm] to 0.8 [0.6-11mm] from baseline to after chest closure. RV longitudinal displacement was reduced from 6.1 [3.4-8.8mm] to 2.9 [0.4-5.4mm] at the same time-points. RV speckle tracking revealed concomitantly that transverse displacement of the free wall increased significantly from 1.2 [0-2.7mm] at baseline to 5.4 [3.6-7.2mm] after chest closure. RV speckle tracking strain did not change significantly. Increased transverse displacement likely compensates for reduction in RV longitudinal contraction following cardiac surgery and maintains cardiac output. The sustained output from the right ventricle was not related to an increased contractility.

Tricuspid Annular Plane Systolic Excursion (TAPSE) for Risk Stratification and Prognostication of Patients with Pulmonary Embolism.

The categorization of pulmonary embolism (PE) as non-massive, sub-massive, and massive helps guide acute management. The presence of right ventricular (RV) strain differentiates sub-massive from non-massive PEs. Unlike laboratory markers and electrocardiogram changes, the classic parameters used in the echocardiographic diagnosis of RV strain have a technical component that is operator-dependent. This narrative review will describe the physiologic effects of a PE on the RV and how this affects prognosis. It will summarize the literature evaluating the accuracy and prognostic ability of tricuspid annular plane systolic excursion (TAPSE) in the echocardiographic assessment of RVfunction. The review will describe the appeal of TAPSE for this purpose, provide cutoff measurements, and then illustrate how to perform the technique itself, while offering associated pearls and pitfalls in this bedside evaluation. RV function and dynamics undergo acute changes in the setting of a PE. RV dysfunction predicts poor outcomes in both the short and long term. However, RV strain is difficult to capture on echocardiography due to the chamber's complex geometric shape and contraction. From the apical four-chamber window, TAPSE offers a quantitative measure that is more easily performed with high interobserver reliability for evaluating systolic RV contraction. This measurement carries prognostic value in patients diagnosed with PE. Along with other more qualitative echocardiographic parameters, TAPSE can be used as a simple quantitative measure of RV dysfunction for differentiating sub-massive from non-massive PEs. This categorization helps guide acute management and disposition.

Resynchronization therapy for failing sub-pulmonary right ventricle in congenital heart disease

Pulmonary right ventricular (RV) dysfunction is present in a number of congenital heart lesions after repair surgery. It is frequently associated with right bundle branch block (RBBB) as a source of electromechanical dyssynchrony which may contribute to RV failure. RV cardiac resynchronization therapy (RV-CRT) may be used to improve RV function, electromechanical synchrony and contraction efficiency. It is effective in the immediate postoperative period as a temporary treatment option. Limited evidence also indicates the effectiveness of permanent RV-CRT. Further studies are needed to better define its role in long-term RV failure management.

5939Perioperative shift in right ventricular mechanical pattern in patients undergoing mitral valve surgery: a predictor of right ventricular failure?

Abstract Background Severe mitral regurgitation (MR) induces significant changes not only in the left, but also in the right ventricular (RV) morphology and function. Early treatment of MR is recommended, however, surgical procedure disrupts the native RV contractile pattern and predisposes the at-risk ventricle to develop postoperative RV failure (RVF) which is associated with poor outcomes. Purpose Accordingly, the PREPARE-MVR study (PRediction of Early PostoperAtive Right vEntricular failure in Mitral Valve Replacement/Repair patients) aims to explore the alterations of RV contraction pattern in patients undergoing MVR and to investigate the association of preoperative echocardiographic findings with early postoperative RVF. Methods We prospectively enrolled 70 patients (62±12 years, 67% males) undergoing open heart MVR. Thirty age and gender matched healthy volunteers served as control group. Transthoracic 3D echocardiography was performed preoperatively and at intensive care unit discharge. Furthermore, focused 2D echocardiogram was also obtained during the ICU stay. Forty-three patients also completed 6 months follow-up. 3D model of the RV was reconstructed and end-diastolic volume index (EDVi) along with RV ejection fraction (RVEF) were calculated. For in-depth analysis of RV mechanics, we decomposed the motion of the RV to compute longitudinal (LEF) and radial ejection fraction (REF). Right heart catheterization was performed to monitor RV stroke work index (RVSWi). Results RV morphology as assessed by EDVi was unaffected by surgery (preoperative vs postoperative; 73±17 vs 71±16 mL/m2, p=NS). RVEF was slightly decreased after MVR (52±6 vs 48±7%, p&lt;0.05), whereas RV contraction pattern has changed notably. Before MVR, the longitudinal shortening was the main contributor to global systolic function (LEF/RVEF vs REF/RVEF; 0.53±0.10 vs 0.43±0.12; p&lt;0.001), whereas in controls the longitudinal and radial shortening contributed equally to RVEF (0.47±0.07 vs 0.43±0.09; p=NS). Postoperatively, the radial motion became dominant (0.35±0.08 vs 0.47±0.09; p&lt;0.001). However, this shift was only temporary as 6 months later the contraction pattern became similar to controls showing equal contribution of the two components (0.44±0.10 vs 0.42±0.11; p=NS). Postoperative RVF (defined as RVSWi &lt;300 mmHg*mL/m2 or ICU TAPSE &lt;10 mm) was detected in 14 [20%] patients. Preoperative LEF was associated with postoperative RVSWi (r=−0.61, p&lt;0.001) and it was an independent predictor of postoperative RVF (OR=1.16 [1.03–1.35], p&lt;0.05). Conclusion Severe MR induces a significant shift in the RV mechanical pattern which may influence the development of postoperative RV dysfunction and failure after MVR. Advanced indices of RV mechanics are associated with invasively measured parameters of RV contractility and may predict postoperative RVF.

Changes in Right Ventricle Function After Mitral Valve Repair Surgery

Right ventricular (RV) dysfunction can occur after cardiac surgery and persist for years. We assessed perioperative RV systolic function in patients undergoing mitral valve (MV) repair and further compared minimally invasive robotic-assisted mitral valve repair (MIMVr) vs standard 'open' MV repair (MVr). Speckle tracking (RV free wall strain [RVS]) was used as a sensitive echocardiography method to assess RV function. Retrospective analysis, over 3 years, of consecutive patients (n = 158) referred to Mayo Clinic (Rochester, MN, USA). Preoperative, pre-discharge and 1 year transthoracic echocardiograms were reviewed. A prospective pilot study was performed for sample size estimation. Primary outcome was RV free wall strain (RVS). Right ventricular free wall strain declined after MV repair surgery (-22.6 ± 7% vs -15 ± 6%, p < 0.001). There were smaller reductions in RVS in MIMVr vs MVr group (-6.0 ± 9% vs -10.3 ± 8%, p < 0.01), which persisted after adjusting for baseline values (RVS treatment effect 1.5%, p = 0.007). There was greater recovery in MIMVr vs MVr group at 1 year follow-up vs pre-surgery values (-3.4 ± 9% vs -8.1 ± 8% respectively, p < 0.001, RVS treatment effect 1.7%, p = 0.001). Bypass time was higher in the MIMVr group (80min ± 22 vs 40min ± 20, p < 0.0001). The echo findings remained significant correcting for age, pulmonary pressures and change in ejection fraction. Right ventricular systolic dysfunction is common after MV repair surgery. Deterioration in RV contraction is less pronounced following MIMVr vs MVr and is associated with enhanced RV functional recovery at 1 year, albeit not to preoperative levels. This may potentially be associated with clinical functional improvement but further studies are warranted to investigate this.

Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices.

Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.

The Combination of Tricuspid Annular Plane Systolic Excursion and HeartMate Risk Score Predicts Right Ventricular Failure After Left Ventricular Assist Device Implantation.

Right ventricular (RV) failure is difficult to predict and is a major determinant of poor outcomes after left ventricular assist device (LVAD) implantation. We evaluated the associations of the following variables with severe RV failure in LVAD patients: tricuspid annular plane systolic excursion (TAPSE), pulmonary artery pulsatility index (PAPi), simplified RV contraction pressure index (sRVCPI), and HeartMate Risk Score (HMRS). We performed a retrospective case-control study on 216 patients who underwent continuous-flow LVAD implantation between 2008 and 2014. The primary analysis assessed the ability of HMRS, PAPi, sRVCPI, and TAPSE to predict severe RV failure. A secondary analysis evaluated the incremental benefit of combining predictive variables. Seventy-four patients developed severe RV failure (24%). Compared with the control group, the severe RV failure group had lower TAPSE (1.30 vs. 1.55; p < 0.001), lower PAPi (1.77 vs. 2.47; p = 0.001), lower sRVCPI (42.71 vs. 57.82; p < 0.001), and higher HMRS (2.12 vs. 1.65; p < 0.001). All four variables had similar receiver operating characteristic curves with modest area under the receiver operating characteristic curve (0.63-0.67, all p values < 0.001). In the evaluation of combined predictive variables, the combination of TAPSE with HMRS was found to be best for predicting severe RV failure. In summary, patients at risk for severe RV failure after LVAD implantation were successfully identified using TAPSE, PAPi, sRCPI, and HMRS. The combination of TAPSE and HMRS-incidentally, the least invasive and most readily available variables-proved to be superior to RV-centric metrics for predicting severe RV failure. The predictive and clinical use of these two variables should be tested prospectively.

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

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. 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±6years) underwent a speckle tracking echocardiography of the RV at rest in normoxia and every 15min during a 60min exposure to hypoxic breathing ( 12%). Ten of the subjects also underwent an incremental cycle ergometry in normoxia to 100W, 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±11ms in spite of mild increases in mean PAP (mPAP) from 15±2 to 20±2mmHg 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±6ms to 14±6ms), while mPAP increased to 25±2mmHg 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.

Morphologic Analysis of the Normal Right Ventricle Using Three-Dimensional Echocardiography–Derived Curvature Indices

Right ventricular (RV) remodeling involves changes in size, wall thickness, function, and shape. Previous studies have suggested that regional curvature indices (rCI) may be useful for RV shape analysis. The aim of this study was to establish normal three-dimensional echocardiographic values of rCI in a large group of healthy subjects to facilitate future three-dimensional echocardiographic study of adverse RV remodeling. RV endocardial surfaces were reconstructed at end-diastole and end-systole in 245 healthy subjects (mean age, 42±12years) and analyzed using custom software to calculate mean curvature in six regions: RV inflow tract (RVIT) and RV outflow tract, apex, and body (both divided into free wall and septal regions). Associations with age and gender were studied. The apical free wall was convex, while the septum (apex and body) was more concave than the body free wall. Septal curvature did not change significantly from end-diastole to end-systole. The RV outflow tract and RVIT became flatter from end-diastole to end-systole. In keeping with the "bellows-like" action of RV contraction, the body free wall became flatter, while the apex free wall changed to a more convex surface. There were no intergender differences in rCI. In older subjects (≥55years of age), the RV free wall and RV outflow tract were flatter, and from end-diastole to end-systole, the RVIT became less flattened and the apex less pointed. These changes suggest that the right ventricle is stiffer in older subjects, with less dynamic contraction of the RVIT and less bellows-like movement. This study established normal three-dimensional echocardiographic values for RV rCI, which are needed to further study RV diastolic dysfunction and remodeling with disease.