Right Ventricular Free Wall Research Articles

Impact of reductive tricuspid ring annuloplasty on right ventricular size, geometry and strain in an ovine model of functional tricuspid regurgitation.

OBJECTIVESReductive ring annuloplasty of the tricuspid annulus represents the contemporary surgical approach to functional tricuspid regurgitation (FTR). We set out to investigate the influence of moderate reductive tricuspid ring annuloplasty on tricuspid regurgitation and right ventricular (RV) size, geometry and strain in an ovine model of chronic FTR.METHODSEight healthy Dorsett male sheep (62.8 + 2kg) underwent a left thoracotomy for placement and tightening of pulmonary artery band to at least double proximal pulmonary artery blood pressure. After 8 weeks of recovery, animals underwent sternotomy, epicardial echocardiography and sonomicrometry crystal implantation. Six crystals were placed around tricuspid annulus and 13 on RV free wall epicardium along 3 parallels defining 3 wall regions (basal, mid and lower) and 1 on the RV apex. All animals underwent beating heart implantation of 26 mm MC3 annuloplasty ring during a second cardiopulmonary bypass run after baseline data acquisition. Simultaneous haemodynamic, sonomicrometry and echocardiography data were acquired at Baseline and after reductive tricuspid ring annuloplasty.RESULTSImplantation of reductive ring annuloplasty resulted in 47 ± 7% annular area reduction (996 ± 152 mm vs 516 ± 52 mm2, P = 0.0002) and significantly decreased RV end-diastolic volume (185 ± 27 vs 165 ± 30 ml, P = 0.02). Tricuspid ring annuloplasty effectively reduced FTR grade (3.75 ± 0.6 vs 0.3 ± 0.5, P = 0.00004) and had little influence on RV function, cross-sectional area, radius of curvature or free wall regional strains.CONCLUSIONSIn adult sheep with 8 weeks of pulmonary artery banding and FTR, tricuspid annulus reduction of 47% with prosthetic ring annuloplasty effectively abolished FTR while maintaining regional RV function and strain patterns.

Pericardial Effusion in Postcoronavirus Disease Patients with Preserved Ejection Fraction of the Left Ventricle and Normal Values of N-Terminal-Pro B-Type Natriuretic Peptide-Link with C-Reactive Protein and D-Dimer.

AimThe aim of this study was to link the values of D-dimer and C-reactive protein (CRP), with the occurrence of pericardial effusion in patients who had coronavirus disease 2019 (COVID-19) and have preserved systolic function of the left ventricle (LV).MethodsThis was a prospective study and included 146 patients who underwent echocardiographic examination 30 days after the acute phase of COVID-19. Patients who were placed on mechanical ventilation, patients who had pulmonary thromboembolism or acute coronary syndrome during the acute period of the disease, patients who had an ejection fraction of the LV <50%, patients who were diagnosed with pericarditis during acute illness or clinical signs of heart failure (or had elevated N-terminal-pro hormone B-type natriuretic peptide value), with verified renal or hepatic dysfunction were excluded from the study, including patients with diabetes mellitus Type 1, patients with cancer, connective tissue disease, or pregnant women. The existence of cardiovascular risk factors (hypertension, diabetes mellitus Type 2, and hyperlipidemia), the presence of previous ischemic heart disease, maximum values of D-dimer, and CRP (during the first 15 days of the disease) was taken into the analysis.ResultsEffusion was verified around the right atrium (RA) in 104 patients (3.85 ± 1.75 mm), in 135 patients next to the free wall of the right ventricle (RV) (5.24 ± 2.29 mm), in front of the apex of the LV in 27 patients (2.44 ± 0.97 mm), next to the lateral wall of LV in 35 patients (4.43 ± 3.21 mm), and behind the posterior wall of LV in 30 patients (2.83 ± 1.62 mm). Mean CRP values during the acute phase of the disease were 43.0 mg/L (8.6–76.2 mg/L), whereas D-dimer mean value was 880.00 μg/L (467.00 –2000.00 μg/L). CRP values correlated with effusion next to the free wall of RV (rho = 0.202; P = 0.018). The D dimer correlated with effusion around RA (rho = 0.308; P = 0.0001).ConclusionThe clinical picture of the post-COVID patients could be explained by the appearance of pericardial effusion. D-dimer value correlates with the occurrence of effusion around RA, whereas CRP value correlates with effusion next to the free wall of RV.

Alterations in right ventricular mechanics in patients with Behcet's disease.

Manifest myocardial involvement is somewhat rare in patients with Behcet's disease (BD), although echocardiographic studies suggest that subclinical alterations in left ventricular (LV) contractility is rather common. Data on right ventricular (RV) involvement in BD is rather scarce.This study aims to determine whether RV systolic performance is affected in BD patients, and to understand the clinical and echocardiographic correlates of RV contractility in these patients.Forty-five patients who fulfilled criteria for BD and 45 age and gender matched controls were enrolled. All participants underwent a comprehensive echocardiographic examination, including deformation imaging, to characterize RV mechanics.Conventional morphologic and echocardiographic indicators of RV morphology and function were not different between groups, but RV apical strain and RV free wall strain (FWS) were significantly lower in BD patients as compared to the controls (P < 0.001 and P = 0.02, respectively). The only significant correlates of FWS were tricuspid regurgitation velocity and related indices in healthy controls, while FWS correlated with LV global longitudinal strain (GLS), morphologic measures of left and right atria and ventricles, and with conventional measures of right ventricular contractility. The relationship between FWS and GLS remained statistically significant after adjusting for other clinical and echocardiographic parameters (β = 0.379, P = 0.01).In patients with BD, there is a subclinical alteration in RV contractility and the degree of alteration in the RV systolic performance paralleled that of LV. Thus, present results support the presence of RV involvement in these patients.

Advanced Echocardiographic Analysis in Medium-Term Follow-Up of Children with Previous Multisystem Inflammatory Syndrome.

Multisystem inflammatory syndrome in children (MIS-C) is a severe hyperinflammatory disease related to SARS-CoV2 infection, with frequent cardiovascular involvement in the acute setting. The aim of the study was to evaluate the cardiac function at 6 months. Thirty-two patients diagnosed with MIS-C were enrolled and underwent advanced echocardiogram at discharge and at 6 months. According to the left ventricular ejection fraction (LVEF) at admission, the patients were divided into group A (LVEF < 45%) and group B (LVEF ≥ 45%) and the follow-up results were compared. At discharge, all patients had normal LV and RV systolic function (LVEF 61 ± 4.4%, LV global longitudinal strain −22.1%, TAPSE 20.1mm, s’ wave 0.13m/s, RV free wall longitudinal strain −27.8%) with normal LV diastolic function (E/A 1.5, E/e’ 5.7, and left atrial strain 46.5%) and no significant differences at 6 months. Compared to group B, the group A patients showed a reduced, even if normal, LV global longitudinal strain at discharge (−21.1% vs. −22.6%, p-value 0.02), but the difference was no longer significant at the follow-up. Patients with MIS-C can present with depressed cardiac function, but if treated, the cardiac function recovered without late onset of cardiac disease. This favorable result was independent of the severity of acute LV dysfunction.

Right atrial reservoir strain and right ventricular strain improves in patients recovered from hospitalisation for non-severe COVID-19

Purpose Those hospitalised with coronavirus disease 2019 (COVID-19) have recently been shown to have impaired right ventricular (RV) strain, but data about the course of heart function after discharge are limited. Our aim was to compare right ventricular strain and right atrial reservoir strain (RASr) associated with COVID-19 between acute disease (during hospitalisation) and follow-up (after discharge). Methods In this retrospective single-center study, we analysed the echocardiograms of 43 patients hospitalised for non-severe COVID-19 between December 2020 and March 2021, undergoing echocardiography both during and after hospitalisation. In addition to conventional echocardiographic parameters, we applied 2-dimensional speckle tracking to obtain RV global longitudinal strain (RV-GLS), RV free wall strain (RV-FWS), and RASr. Results Mean (standard deviation) age of the study population was 50 (9) years, and 18 (42%) of the participants were women. Median duration between exams was 6 months (range, 5–7 months). Both mean RV-GLS and mean RV-FWS significantly increased at follow-up (−20.8 [3.8] vs. −23.5 [2.8], p < 0.001 and −23.3 [4.2] vs. −28.2 [2.8], p < 0.001; respectively), and RASr significantly improved as well (−32.3 [6.6] vs. −41.9 [9.8], p < 0.001). Conclusion In patients hospitalised for non-severe COVID-19 pneumonia, RV-GLS, RV-FWS, and RASr improved significantly between acute disease and 6 months after discharge.

Invasive Hemodynamic Assessment and Procedural Success of Transcatheter Tricuspid Valve Repair-Important Factors for Right Ventricular Remodeling and Outcome.

IntroductionSevere tricuspid regurgitation (TR) is a common condition promoting right heart failure and is associated with a poor long-term prognosis. Transcatheter tricuspid valve repair (TTVR) emerged as a low-risk alternative to surgical repair techniques. However, patient selection remains controversial, particularly regarding the benefits of TTVR in patients with pulmonary hypertension (PH).AimWe aimed to investigate the impact of preprocedural invasive hemodynamic assessment and procedural success on right ventricular (RV) remodeling and outcome.MethodsAll patients undergoing TTVR with a TR reduction of ≥1 grade without precapillary or combined PH [mean pulmonary artery pressure (mPAP) ≥25 mmHg, mean pulmonary artery Wedge pressure ≤ 15 mmHg, pulmonary vascular resistance ≥3 Wood units] were assigned to the responder group. All patients with a TR reduction of ≥1 grade and precapillary or combined PH were classified as non-responders. Patients with a TR reduction ≥2 grade were directly classified as responders, and patients without TR reduction were directly assigned as non-responders.ResultsA total of 107 patients were enrolled, 75 were classified as responders and 32 as non-responders. We observed evidence of significant RV reverse remodeling in responders with a decrease in RV diameters (−2.9 mm, p = 0.001) at a mean follow-up of 229 days (±219 SD) after TTVR. RV function improved in responders [fractional area change (FAC) + 5.7%, p < 0.001, RV free wall strain +3.9%, p = 0.006], but interestingly further deteriorated in non-responders (FAC −4.5%, p = 0.003, RV free wall strain −3.9%, p = 0.007). Non-responders had more persistent symptoms than responders (NYHA ≥3, 72% vs. 11% at follow-up). Subsequently, non-response was associated with a poor long-term prognosis in terms of death, heart failure (HF) hospitalization, and re-intervention after 2 years (freedom of death, HF hospitalization, and reintervention at 2 years: 16% vs. 78%, log-rank: p < 0.001).ConclusionHemodynamic assessment before TTVR and procedural success are significant factors for patient prognosis. The hemodynamic profiling prior to intervention is an essential component in patient selection for TTVR. The window for edge-to-edge TTVR might be limited, but timely intervention is an important factor for a better outcome and successful right ventricular reverse remodeling.

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

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. 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.

Evaluation of Right Ventricular Myocardial Mechanics by 2- and 3-Dimensional Speckle-Tracking Echocardiography in Patients With an Ischemic or Non-ischemic Etiology of End-Stage Heart Failure

BackgroundThe aims of our study were (1) to assess the right ventricular (RV) myocardial mechanics by two-dimensional (2D) and three-dimensional (3D) speckle-tracking echocardiography (STE) in patients with an ischemic or non-ischemic etiology of end-stage heart failure (HF) and (2) to explore which RV index evaluated by 2D- and 3D-STE was the most powerful indicator for identifying the ischemic and non-ischemic etiologies of end-stage HF.MethodsA total of 96 patients with left ventricular ejection fraction (LVEF) < 30% were enrolled in our study: 42 patients (mean age, 52 ± 10 years; 9.5% female) with ischemic cardiomyopathy and 54 patients (mean age, 46 ± 14 years; 16.7% female) with non-ischemic cardiomyopathy. A total of 45 healthy subjects (mean age, 46 ± 13 years; 24.4% female) served as controls. The longitudinal strain of the RV free wall (RVFWLS) was determined by both 2D- and 3D-STE.ResultsCompared to controls, patients with an ischemic or non-ischemic etiology of end-stage HF had lower 2D-RVFWLS, 3D-RVFWLS and RV ejection fraction (RVEF) values (P < 0.05). Patients with non-ischemic cardiomyopathies (NICMs) had significantly lower 3D-RVFWLS and RVEF values than in those with ischemic cardiomyopathies (ICMs), whereas 2D-RVFWLS and conventional RV function parameters did not differ between the two subgroups. RVEF was highly related to 3D-RVFWLS (r = 0.72, P < 0.001), modestly related to 2D-RVFWLS (r = 0.51, P < 0.001), and weakly related to conventional RV function indices (r = –0.26 to 0.46, P < 0.05). Receiver operating characteristic curve analysis revealed that the optimal 3D-RVFWLS cut-off value to distinguish NICM from ICM patients was –14.78% (area under the curve: 0.73, P < 0.001), while 2D-RVFWLS and conventional RV echocardiographic parameters did not.ConclusionOur study demonstrated the superiority of 3D-RVFWLS over 2D-RVFWLS and conventional RV function indices in identifying the ischemic and non-ischemic etiologies of end-stage HF. These findings support the idea that 3D-RVFWLS may be a promising non-invasive imaging marker for distinguishing NICM from ICM.

Endocardial ablation of ventricular tachycardia ablation in arrhythmogenic right ventricular cardiomyopathy aiming epicardial late potential abolition

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is frequently needed to treat ventricular tachycardia (VT) in ARVC patients. Ablation aiming non-inducibility (NI) and late potential (LP) abolition has been shown to be effective1. Simultaneous endo-epicardial mapping demonstrate epicardial involvement in most VT2. However epicardial fat and vicinity of coronary artery may prevent effective epicardial ablation. Aims (a) evaluate endocardial-only ablation guided by epicardial late-potential recording (EA-ELP) to achieve LP abolition (LPA) and NI; (b) measure ablation-index(AI) values allowing epicardial LP suppression by endocardial ablation, as a surrogate for transmurality. Methods From 2019 to 2021 the authors (XW, EG) evaluated EA-ELP in ARVC patients patient referred for ablation. Our ablation protocol was previously described3. Endo and epicardial voltage mapping of the right ventricle (RV) were performed in sinus rhythm using 0.5-1.5 mV threshlods for endocardial scar and 0.5-1 mV for the epicardial. All LP were manually tagged. Programmed ventricular stimulation (PVS) was performed till S4 from the RV apex and other sites, all inducible tolerated VT were mapped. Endocardial ablation was performed with an irrigated tip catheter positioned in front of epi-LP recorded by a multi-electrode catheter aiming to eliminate or delay epi-LP as a surrogate for transmurality. For each lesion fulfilling the «transmurality criteria», the AI values were recorded. Remap was performed to validate LPA and NI was tested. Patient follow-up (FU) rely on telemonitoring in ICD-carriers and holter/exercise test for the others. Results 11 patients were enrolled (9M/2F, mean age 45 years), 9 for VT recurrence (3 redo) and 2 for de novo VT. The median ICD therapy before ablation was 5/patient (mean 1.7). The clinical VT originated from the RV outflow tract (RVOT) in 5 patients, peritricuspid (PT) in 2, RV free wall (RFW) in 4. Substrate were more extended in the epicardium compared to the endocardium: epi-LP and scar surfaces were 42.5 cm2/118 cm2 versus 24.5 cm2/25.5 cm2 for the endocardium. In one patient, additional epicardial lesion was necessary to achieve LPA. The mean ablation duration was 3377 s. Remap showed LPA in all patients and PVS was negative in all (not tested in one due to hemodynamic instability). One patient presented retrosternal hematoma after ablation with spontaneous favorable outcome. Endocardial AI values allowing epi-LP abolition were 595 for the inferior wall, 625 in the RVOT, 604 for PT and 639 for RFW. During a mean FU of 12 months (median 16.5 mths), only one patient had VT recurrence. Conclusion Based on this case-series, EA-ELP appeared as a safe and effective method to treat VT in ARVC. EA-ELP ablation allowed VT suppression in 91 % of patients after an mean FU of 12 mths. The RV endocardial AI needed to suppress epi-LP ranged was between 595-639 and could be used as surrogate for transmurality in ARVC.

P237 INFLUENCE OF HEART RATE ON LEFT AND RIGHT VENTRICULAR LONGITUDINAL STRAIN IN PATIENTS WITH CHRONIC HEART FAILURE

Abstract Background Myocardial deformation evaluated by two–dimensional speckle tracking echocardiography (STE) is a useful tool to evaluate both left and right ventricular function. However, there are no conclusive data about the relationship between strain measures and heart rate (HR). Aim of the Study To analyse changes in left (LV) and right ventricular (RV) longitudinal strain associated with variations of HR in patients with and without chronic heart failure (CHF). Methods. We enrolled 45 patients. Of the 38 patients diagnosed with CHF, 21 were carrying an ICD (Group 1), and 17 an ICD with CRT (Group 2). Group 3 included 7 participants without CHF with sinus node dysfunction that were carrying a pacemaker. The frequency of atrial stimulation was increased to 90 beats/min and an echocardiogram was performed at each increase of 10 beats/min. Global LV and RV longitudinal strain (LVGLS and RVGLS, respectively) and RV free wall longitudinal strain (RVfwLS) were calculated at each HR, together with other echocardiographic parameters. Worsening or improvement of strain measures was defined as a relative change from baseline of 10%. Results The reproducibility of strain measurements was assessed in all the images obtained at the different HRs for 19 of the study participants. A high degree of reproducibility was observed for LVGLS (ICC = 0.96; 95% CI, 0.93 – 0.97) as well as for RVGLS (ICC = 0.91; 95%CI, 0.86 – 0.94) and RVfwLS (ICC = 0.91; 95%CI, 0.85 – 0.94). When analysed as continuous variables, significant reductions in LVGLS were detected at higher HRs, whereas improvements in both RVGLS and RVfwLS were observed (left panels of the figure). Patients with worsening of LVGLS (76% overall) were more likely to present lower baseline LV function and maximum relative changes of LVGLS correlated significantly with the E/e’ ratios (r = –0.56; p &amp;lt; 0.001). Only few patients (18% for RVGLS and 16% for RVfwLS) exhibited HR–related worsening of RV strain measures, which was associated with lower levels of baseline RV function and higher pulmonary systolic pressures. Finally, 21 (47%) and 25 (56%) of the participants responded with improvements in RVGLS and RVfwLS, respectively. Right panels of the figure show the trend of left and right measures in the different groups. Conclusions Our findings revealed heterogeneous RV and LV responses to increases in HR. These findings might ultimately be used to optimize cardiac functionality at rest in patients diagnosed with CHF.

Right Ventricular Dysfunction Predicts Outcome in Acute Heart Failure.

AimThe severity of cardiac impairment in acute heart failure (AHF) predicts outcome, but challenges remain to identify prognostically important non-invasive parameters of cardiac function. Left ventricular ejection fraction (LVEF) is relevant, but only in those with reduced LV systolic function. We aimed to assess the standard and advanced parameters of left and right ventricular (RV) function from echocardiography in predicting long-term outcomes in AHF.MethodsA total of 418 consecutive AHF patients presenting over 12 months were prospectively recruited and underwent bedside echocardiography within 24 h of recruitment. We retrospectively assessed 8 RV and 5 LV echo parameters of the cardiac systolic function to predict 2-year mortality, using both guideline-directed and study-specific cutoffs, based on the maximum Youden indices via ROC analysis. For the RV, these were the tricuspid annular plane systolic excursion, RV fractional area change, tissue Doppler imaging (TDI) peak tricuspid annular systolic wave velocity, both peak- and end-systolic RV free wall global longitudinal strain (RV GLS) and strain rate (mean RV GLSR), RV ejection fraction (RVEF) derived from a 2D ellipsoid model and the ratio of the TAPSE to systolic pulmonary artery pressure (SPAP). For the LV, these were the LVEF, mitral regurgitant ΔP/Δt (MR dP/dt), the lateral mitral annular TDI peak systolic wave velocity, LV GLS, and the LV GLSR.ResultsA total of 7/8 parameters of RV systolic function were predictive of 2-year outcome, with study cutoffs like international guidelines. A cutoff of < −1.8 s–1 mean RV GLSR was associated with worse outcome compared to > −1.8 s–1 [HR 2.13 95% CI 1.33–3.40 (p = 0.002)]. TAPSE:SPAP of > 0.027 cm/mmHg (vs. < 0.027 cm/mmHg) predicted worse outcome [HR 2.12 95% CI 1.53–2.92 (p < 0.001)]. A 3-way comparison of 2-year mortality by LVEF from the European Society of Cardiology (ESC) guideline criteria of LVEF > 50, 41–49, and < 40% was not prognostic [38.6% vs. 30.9 vs. 43.9% (p = 0.10)]. Of the 5 parameters of LV systolic function, only an MR dP/dt cutoff of < 570 mmHg was predictive of adverse outcome [HR 1.63 95% CI 1.01–2.62 (p = 0.047)].ConclusionWith cutoffs broadly like the ESC guidelines, we identified RV dysfunction to be associated with adverse prognosis, whereas LVEF could not identify patients at risk.

C38 RIGHT VENTRICULAR FREE WALL LONGITUDINAL STRAIN (RVFWSL) A NEW OUTCOME PREDICTOR IN PATIENTS CANDIDATE FOR TAVI

Abstract Background Right ventricular (RV) systolic dysfunction is considered an outcome predictor in various cardiovascular diseases. RV dysfunction, assessed by RV free wall longitudinal strain (RVFWSL) in patients candidate for trans–catheter aortic valve implantation (TAVI), has not been extensively explored as an outcome predictor. Purpose Evaluate the prognostic value of pre intervention RVFWSL in patients undergoing TAVI. Methods: retrospective analysis of 100 patients who underwent transfemoral TAVI in our hospital from 2015 to 2019, with at least a pre and post–TAVI echocardiography. Clinical and echocardiographic data before and after TAVI and follow–up data were collected. We considered the value of [23.3]% the cut–off of normality for RVFWSL. The primary end–point was a composite of death from any cause and hospitalization for heart failure. Results The median age of the patients was 81 years (79–83) with a functional status NYHA II–III (81%) before the intervention. EF was preserved in most of the patients (median 56%, 55–58), while Right ventricle dysfunction assessed with RVFWLS was reduced in half of the patients at baseline. At a median follow–up of 1023 days (630–1387), the univariate analysis demonstrated a predictive value for a reduced RVFWSL ( &amp;lt; [23.3]%, P = 0.015) and EF &amp;lt; 50% (P = 0.014) before TAVI. Cox regression analysis found that pre–TAVI reduced RVFWSL (HR 2.875, I.C. 95% 1.113–7.425; P = 0.03) and EF &amp;lt; 50% (HR 2.511, I.C. 95% 1.07–5.892; P = 0.03) were independently associated with composite end–point of the study. Moreover, a reduced EF associated with RVFWSL &amp;lt; [23.3]% showed an incremental value in predicting the outcome (P = 0.021). Conclusions Among patients with severe aortic stenosis undergoing TAVI, a reduced pre–implant RVFWSL is able to predict long–term outcome.

The prevalence and clinical significance of a reduced ventricular ejection fraction in asymptomatic young elite endurance athletes

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council of Australia Background Ventricular ejection fraction (EF) is the most widely used parameter to evaluate ventricular systolic function. Endurance athletes presenting with a reduced ventricular EF often raise the question of an underlying dilated or arrhythmogenic cardiomyopathy. The clinical significance of a reduced EF in athletes remains to be elucidated. Purpose To investigate the prevalence and clinical significance of a reduced EF in asymptomatic endurance athletes. Methods Two hundred eighteen asymptomatic young elite endurance athletes were evaluated at baseline. Cardiac magnetic resonance imaging (CMR) was performed to assess cardiac volumes, left ventricular and right ventricular EF (LVEF and RVEF), mass and fibrosis. Athletes with reduced EF (ATrEF) were defined as those having LVEF&amp;lt;50% and/or RVEF&amp;lt;45%. Ventricular systolic and diastolic function were assessed by trans-thoracic echocardiography. A 12-lead ECG and 24-hour holtermonitoring assessed electrical alterations and arrhythmias. In 145 athletes, LV and RV contractile reserve was evaluated by exercise CMR. Cardiopulmonary testing was performed in all athletes to measure maximal oxygen uptake (VO2max). Results Thirty-one ATrEF (14.2%) were compared to 187 athletes with a preserved EF (ATpEF). ATrEF were more frequently males (93 vs 77% male, p=0.033) but did not differ from ATpEF with regard to age (18.8±2.1 vs 18.3±2.1 years, p=0.25). Ten athletes had an isolated reduced LVEF, 10 had an isolated reduced RVEF and 11 had both a reduced LVEF and RVEF. ATrEF had similar end-diastolic volumes and cardiac mass but differed by higher end-systolic volumes. Peak exercise LVEF and RVEF determined by exercise CMR remained lower in ATrEF (68±3 vs 73±4% and 62±6 vs 69±5%, p&amp;lt;0.001) but contractile reserve was greater (ΔLVEF 18±5 vs 14±4% and ΔRVEF 19±5 vs 15±5%, p&amp;lt;0.01). A reduced EF was not associated with lower exercise capacity, in fact VO2max was higher in ATrEF than in ATpEF (65±6 vs 62±9mL/kg/min, p=0.020) and the percentage of predicted VO2max by the Wasserman equation were similar (151±14 vs 149±21%, p=0.533). Fibrosis was present in 3 ATrEF and 18 ATpEF (9.7 vs 9.6%, p=0.993) and was isolated to the RV hinge-points in all but 3 ATpEF who had midmyocardial LV lateral wall fibrosis. LV systolic strain (-17.5±2.0 vs -19±2.1%, p&amp;lt;0.001) was lower in ATrEF whereas RV free wall systolic strain (-24.9±3.7 vs -25.1±3.5%, p=0.776) was similar. Diastolic function was normal in all ATrEF and ATpEF. Pathologic T-wave inversions were present in 2 ATrEF and 13 ATpEF (6.5 vs 7%, p=0.999). Ventricular premature beats (VPB) were infrequent but more prevalent in ATrEF than in ATpEF (2[0-18] vs 1[0-2]/24h, p=0.025; 16.1 vs 2.7% &amp;gt;100/24h, p=0.006). Conclusion A reduced ventricular EF is common in asymptomatic young elite endurance athletes, is more frequent in males but is not associated with structural, functional or electrical abnormalities apart from a minor excess in VPB.

Influence of heart rate on right ventricular function assessed by right heart catheterization and echocardiography in healthy anesthetized dogs.

BackgroundRight ventricular (RV) functional assessment has received considerable attention in veterinary medicine since various diseases, such as cardiovascular, respiratory, endocrine, and neoplastic disease, may affect RV function. Heart rate (HR) is an important factor that can influence RV function through changes in loading condition and contractility. However, no study has yet evaluated the association between HR and RV function in the same individuals. This study aimed to evaluate the influence of elevated HR on RV function using right heart catheterization and echocardiography, and investigate the association between right heart catheterization and echocardiographic indices.ResultsRight atrial pacing was performed in eight dogs at 120, 140, 160, and 180 bpm. With an increase in HR, the RV systolic volume, RV diastolic volume, and stroke volume significantly decreased; however, the cardiac output, end-systolic elastance (Ees), and effective arterial elastance (Ea) significantly increased. Significant changes were not observed in RV pressure and Ees/Ea. The RV area normalized by body weight, RV fractional area change normalized by body weight (RV FACn), and tricuspid annular plane systolic excursion normalized by body weight (TAPSEn) significantly decreased with increased HR. Peak systolic myocardial velocity of the lateral tricuspid annulus (RV s’), RV strain, and RV strain rate of only the RV free wall analysis (RV-SrL3seg) showed no significant changes with the increase in HR; however, there was an increase in the RV strain rate of the RV global analysis (RV-SrL6seg). Multiple regression analysis revealed that HR, RV FACn, and RV- SrL6seg had significant associations with the Ees, and the TAPSEn and RV-SrL3seg with Ees/Ea.ConclusionsDecreased venous return and shortened relaxation time decreased the RV FAC, TAPSE, RV s’, and RV strain, and might underestimate the RV function. Ees increased with the increase in HR, reflecting the myocardial force-frequency relation; as a result, RV-SrL6seg could be a useful tool for Ees estimation. Additionally, the RV-SrL3seg could detect RV performance, reflecting the balance between RV contractility and RV afterload.

Old and new echocardiographic parameters to predict successful VA ECMO weaning

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): ESC Research Grant 2018, App000021138. Introduction Venoarterial extracorporeal membrane oxygenation (VA ECMO) is a type of temporary mechanical circulatory support (MCS) for acute cardiovascular failure. The population of VA ECMO patients is characterised by high mortality rates. No protocol for weaning from VA ECMO has been validated worldwide. The decision to wean a patient from VA ECMO is challenging because it is necessary to understand whether the patient can tolerate VA ECMO removal, but it is also important to avoid any delay to avoid complications. Purpose the aim of this pilot study was to assess whether strain by speckle tracking could give additional information to haemodynamic, and conventional echocardiographic parameters in identifying patients who develop adverse outcomes within 3 (± 1) months from VA ECMO removal. Methods observational prospective pilot study delivered over 3 years in 2 ECMO centres. The VA ECMO patients who underwent VA ECMO removal (not for palliation) after a weaning trial have been recruited and followed up. Conventional echocardiographic, haemodynamic and strain parameters (recorded during the VA ECMO weaning trial) of patients developing a composite clinical outcome (ClO) within 3 (± 1) months post VA ECMO removal (death for any reason, new necessity of high dose of ino-vasopressors or MCS after VA ECMO removal, new hospitalisation for heart failure) have been compared with those of patients free from ClO. A sub-analysis on composite cardiac outcome (CaO) development and an exploratory ROC analysis have been performed. Results Over 3 years of recruitment, 92 VA ECMO patients have been screened. 21 patients met the eligibility criteria for the study and 19 patients could be analysed. 5 patients experienced ClO (3 had CaO, 2 were complicated by septic shock necessiting high dose of ino-vasopressors). As reported in Figure 1, there were no differences between ClO+ and ClO– patients apart from indexed end diastolic volume (iEDV). iEDV was significantly lower in ClO– patients compared to the others (respectively 44.7 ml m-2 IQR 17.9; 70.4 ml m-2 IQR 43.0, p &amp;lt; 0.01). Focusing on CaO development, the median iEDV remained significantly higher in CaO+ (112.5 ml min-1m-2 IQR 47.1; p = 0.01). Furthermore, the median circumferential strain (absolute value) and the ejection fraction (EF) were significantly lower in CaO+ (Figure 2). At the ROC analysis, the best cut point to discriminate ClO+ and ClO- patients was: for EF 26.32% (AUC 0.79), for cardiac index 2.5ml min-1 m-2 (AUC 0.71) and for right ventricle (RV) free wall longitudinal strain -12.0%. (AUC 0.75). Conclusions VA ECMO weaning procedure is complex and requires the assessment of multiple variables. According to our analysis, large iEDV and low EF predispose to the development of CaO. Furthermore, low absolute values of circumferential strain and RV free wall longitudinal strain may be indicative of development of CaO and ClO respectively. The study is limited by the small number of events.

PO-714-02 RIGHT VENTRICULAR EPICARDIAL ACTIVATION DELAY IN ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY PATIENTS AND GENE CARRIERS UNMASKED BY BODY SURFACE MAPPING SYSTEM

ARVC is afflicted by life-threatening ventricular arrhythmias even before the manifestations of right ventricular (RV) structural abnormalities. Therefore, an early diagnosis is crucial albeit still challenging. To investigate whether a 252-leads noninvasive Body Surface Mapping (BSM) system could detect epicardial conduction delays in ARVC patients and unaffected gene-carrying family members (GC). Twelve ARVC patients, 20 GC and 8 gene-negative family members serving as controls (C) underwent 12-lead ECG, signal-averaged-electrocardiogram (SAECG), echocardiography, 252-lead BSM recordings and thoracic CT scan. Reconstructed epicardial signals were analysed using the Activation Time Editing tool of the activation map. Local depolarisation was defined as the steepest negative dV/dt of the unipolar local epicardial signal. The time from the earliest start of RV epicardial activation to the earliest local depolarisation (ELD) and to the latest local depolarisation (LLD), respectively, were measured separately for the RV free wall (RFW), inferior wall (RIW) and the whole RV. The activation duration, defined as LLD-ELD, was calculated for RFW, RIW and the whole RV. The ELD was similar in all study groups whereas the LLD in the RFW and whole RV was significantly longer among ARVC patients compared to C, but similar in the RIW. Similarly, the activation durations in the RFW and whole RV were significantly longer in ARVC patients but did not differ in the RIW among the groups. A 43ms LLD cut off in the RV and 20 msec activation duration cut off in the RV discriminated ARVC patients from C with highest sensitivity and specificity. Based on these cut-offs, 40% of GC group had longer LLD times and 20 % had also longer activation duration (figure 1). ARVC patients demonstrated prolonged LLD and activation duration times in the RFW and whole RV compared to C. The finding that prolonged conductions could be demonstrated in the GC group as well suggest that the 252-leads noninvasive BSM system may be used as screening tool for the detection of early delays of the RV epicardial activation. Larger studies are required to confirm our results.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A New High‐Speed Biaxial Testing System for Rodent Myocardium Viscoelastic Measurement under Dynamic Loadings

IntroductionMyocardium stiffening is well known in heart failure (HF) development, and it contributes to cardiac dysfunction. Myocardium is viscoelastic, which means that both elastic and viscous resistance exist under dynamic loading. There are limited studies of myocardium viscoelasticity, particularly for the right ventricle (RV). Because viscoelasticity is a time‐ and strain‐dependent mechanical behavior, the measurement at physiological rates &amp; non‐linear deformation is critical. This study aims to develop a high‐speed biaxial tester that induces physiological deformation to characterize RV viscoelasticity in rats.MethodsTo enable the viscoelasticity measurement at physiological conditions, we built a biaxial tester that induces non‐linear, cyclic stretch of myocardium at rodent heart rates. Biaxial sinusoidal stretches were induced by actuators (1400mm/s) (Zaber), forces were recorded by load cells (Honeywell) at 1 kHz, and strains were obtained by a high‐speed camera (Baumer) at up to 200 fps. The LabVIEW and MATLAB codes were developed for performing biaxial tests at various frequencies with synchronized force and image data acquisition. To validate the biaxial tester, isotropic polydimethylsiloxane (PDMS) was used due to its similar viscoelasticity to cardiovascular tissues. PDMS sheets were prepared (Sylgard 184) for equibiaxial tests. Then, consistency between different axes’ measurements, synchronization of the axes’ movement, and accurate viscoelastic measurement were evaluated. Next, we performed equibiaxial cyclic sinusoidal tests on healthy rat RVs. After euthanasia, RV free wall was dissected and mounted. The outflow track direction was defined as the longitudinal direction. The RV was placed in a relaxant solution prior to testing, then preloaded by ~0.1 N and preconditioned by 15 cycles. Stress‐strain loops were derived for viscoelastic analysis.ResultsFirst, we examined if the biaxial tester could achieve planar biaxial tests at desired frequencies. The equibiaxial data obtained from PDMS sheets showed that the tester induced cyclic sinusoidal stretch at various frequencies up to 8 Hz (Fig. 1a), and the viscoelastic behavior measured at two axes were very close (Fig. 1b), thus confirming the tester’s accurate biaxial measurement of the isotropic material. The PDMS clearly showed frequency‐dependent changes in the hysteresis loops (Fig. 1c), with trends of increasing elasticity (slope of loop) and viscosity (area of loop) at higher frequencies. We further derived the viscosity by measuring Tan(δ) (Fig. 1d). The frequency‐dependent elasticity and viscosity of the PDMS sheet were consistent with literature data. Next, we obtained preliminary viscoelasticity data of healthy rat RVs (at 0.1‐2 Hz). Our data showed strain‐rate dependent changes in the hysteresis loops (Fig. 2). The dissipated energy (loop area) as well as the stiffness (loop slope) of the RV tended to increase with increasing frequency. The RV tissue showed similar viscoelastic behavior in both directions at all frequencies.ConclusionOur data showed that this novel testing system enables biaxial viscoelastic measurement of myocardium under physiological conditions (0.1‐8Hz) across small and large animal species. The establishment of this system allows further exploration of RV tissues at higher frequencies (5‐8 Hz) and in diseased states, which will improve the understanding of cardiac biomechanics in HF progression.

Role of cardiomyocytes in right ventricle viscoelasticity with pulmonary hypertension development

BackgroundThe myocardium is viscoelastic, which means there exists elastic and viscous resistant forces during cardiac motion. It has been shown that cardiomyocyte (CM) or muscle fiber has significant viscoelasticity, and microtubule depolymerization via colchicine treatment reduces the CM’s viscoelasticity. However, most prior study is focused on the left ventricle, and the role of CM in right ventricle (RV) viscoelasticity in healthy and pulmonary hypertensive (PH) states is poorly understood. Our goal is to evaluate the contribution of CM to RV viscoelasticity in healthy and PH rats. We hypothesize that CM contributes to both healthy and PH RV viscoelasticity.MethodsAll procedures were approved by Colorado State University IACUC. 6‐week‐old male rats were treated with 3‐week monocrotaline (MCT) (60 mg/kg) to induce PH, and intact healthy rats served as control. RV function was quantified by echocardiography and in vivo pressure‐volume (PV) measurements. After euthanasia, RV free wall underwent equibiaxial stress relaxation in a relaxant bath to obtain passive, biaxial viscoelasticity pre and post colchicine treatment (0.3mM). The tissue was stretched at 20% of strain and with physiological ramp speed (5Hz). Relaxation modulus and normalized stress at 0.01 s were used to quantify elasticity and viscosity. Student t test was performed.ResultsIn vivo RV function measurements showed the development of PH and RV failure in MCT rats (Table 1). Marked RV dilation and decreased fractional shortening confirmed the RV failure establishment. PV loop data with fewer samples (n=3) also implies declines in cardiac output, contractility (Ees) and ventricular‐vascular coupling (Ees/Ea). At the baseline, PH development led to increased viscoelasticity in the RV (Fig. 1). Mechanical data before and after colchicine treatment showed reduced elasticity in both healthy and MCT RVs (Fig. 1A&amp;B). The percentage reduction in elasticity was similar between groups, indicating a similar contribution of CM to RV elasticity. Unexpectedly, we did not observe significant change in viscosity after colchicine treatment in both groups (Fig. 1C&amp;D). Moreover, the control RVs were isotropic, whereas the MCT RVs showed marked anisotropy in elasticity (Fig. 1B).ConclusionOur results demonstrated similar impact of CM on RV viscoelasticity before and after PH development, despite the CM hypertrophy. Colchicine reduced elasticity in healthy and MCT RVs, but minimally changed RV viscosity. These findings will deepen the understanding of biomechanical mechanism of RV failure associated with viscoelastic changes.

Cardiopulmonary protection against nicotine‐induced pulmonary hypertension and right ventricular remodeling in mice is not mediated by ovarian hormones

IntroductionElectronic cigarette use has increased globally prompting a joint committee of international cardiovascular research organizations to call for improved understanding of the health effects of nicotine. Our group has previously demonstrated that chronic, inhaled nicotine induces pulmonary hypertension (PH) and right ventricular (RV) remodeling in male but not female mice, suggesting sex differences in nicotine‐related pathology. Clinically, biological females develop PH more often, but have less severe disease than biological males, likely due to the cardiopulmonary protective effects of estrogen. Nicotine is also metabolized more rapidly in biological females due to sex hormone‐mediated differences in cytochrome P450 activity. These findings led us to hypothesize that female mice are protected against nicotine‐induced PH by a sex hormone‐dependent mechanism. Here, we assessed the role of ovarian hormones in a murine model of nicotine‐induced PH.MethodsFemale C57BL/6J mice were ovariectomized (OVX) one week prior to nicotine exposure. Intact and OVX mice were exposed to nicotine vapor or room air for 12 hours per day for 8 weeks. Nicotine exposure was measured using serum cotinine, which was comparable to human electronic cigarette users, and was not significantly different between intact (421 ± 101 ng/mL) and OVX (314 ± 61 ng/mL) mice. Cardiac structure and function were assessed using echocardiography and RV catheterization.ResultsIn contrast to previous findings in male mice, inhaled nicotine does not cause PH (measured by RV systolic pressure, RVSP) in intact female mice (24.0 ± 0.5 mmHg, n=7 in air vs. 22.7 ± 0.4 mmHg, n=9 in nicotine). RVSP was also unaffected by OVX (24.4 ± 0.9 mmHg, n=9 in air vs. 23.6 ± 0.6 mmHg, n=10 in nicotine). RV free wall thickness during diastole (RV FWT;d) was not significantly different between air‐exposed intact mice (0.328 ± 0.023 mm, n=8), nicotine‐exposed intact mice (0.292 ± 0.015 mm, n=10), air‐exposed OVX mice (0.315 ± 0.021 mm, n=8), and nicotine‐exposed OVX mice (0.293 ± 0.013 mm, n=10). RV internal diameter during diastole (RVID;d) was, likewise, not significantly different between air‐exposed intact mice (1.30 ± 0.03 mm, n=8), nicotine‐exposed intact mice (1.34 ± 0.04 mm, n=10), air‐exposed OVX mice (1.23 ± 0.05 mm, n=8), and nicotine‐exposed OVX mice (1.24 ± 0.05 mm, n=10).ConclusionIn this study, we found no differences in serum cotinine, RVSP, RV FWT;d, or RVID;d between intact and OVX females, leading us to conclude that ovarian hormones do not mediate cardiopulmonary protection against nicotine‐induced PH. Due to profound sex differences in clinical PH pathogenesis and nicotine metabolism, further studies (including exploration of androgen‐driven RV remodeling) are necessary to illuminate mechanisms underlying protection from nicotine‐induced pathology in female mice.

Composite reconstruction of right ventricle and tricuspid valve for cardiac angiosarcoma

Composite reconstruction of right ventricle and tricuspid valve for cardiac angiosarcoma