Outflow Tract Diameter Research Articles

A077 Incidence, Predictors and Prognostic Impact of Patient-Prosthesis Mismatch Following Transcatheter Aortic Valve Implantation

Patient-prosthesis mismatch (PPM) describes a state where the effective orifice area (EOA) of a valve prosthesis is too small relative to the patient's body surface area (BSA). We reviewed the incidence and prognostic impact of PPM following transcatheter aortic valve implantation (TAVI). A retrospective review of patients undergoing TAVI in the Auckland Region between October 2011 and December 2018 was performed. PPM was classified as severe (<0.65 cm2/m2), moderate (0.65-0.85 cm2/m2), or none (>0.85 cm2/m2) on post-TAVI echocardiography. Multivariable logistic regression analysis was used to determine independent predictors of PPM. One-year clinical outcomes were analysed. A total of 294 patients were included in this study (median age 81 years, interquartile range [IQR] 76 to 85 years], BSA 1.87m2, IQR 1.69 to 2.05m2). SAPIEN XT or S3 valves were used in 239 patients (81.3%) and 24 (8.2%) had valve-in-valve TAVI. Moderate and severe PPM were observed following TAVI in 42 (14.3%) and 26 (8.8%) patients respectively. In our multivariate analysis, larger BSA, smaller left ventricular outflow tract (LVOT) diameter and valve-in-valve procedures were identified as independent predictors of severe PPM. There was no significant difference in 30 day or 1-year mortality between PPM groups. Larger BSA, smaller LVOT diameter and valve-in-valve TAVI were predictors of moderate or severe PPM. PPM did not have a significant prognostic impact on mortality following TAVI, consistent with larger international registries.

P1742 Occurrence of right ventricle dysfunction in patients with Brugada syndrome: a follow-up study by echocardiography and electrophysiological examination

Abstract Background Brugada syndrome (BrS) has been characterized by no apparent structural abnormalities in both ventricles, but, recently, the presence of subtle right ventricular (RV) structural abnormalities in patients with BrS has been reported. Purpose The aim of this study was to evaluate the occurrence of RV dysfunction in patients with BrS and their characteristics. Methods We enrolled 49 consecutive patients (54 ± 11 years old) diagnosed with Brs and underwent echocardiography from 2017 to 2018. The echocardiographic parameters and electrophysiological examinations were evaluated including RV size and function such as RV outflow and inflow tract diameter, TAPSE, S’, and FAC. Abnormality threshold for parameters of RV dysfunction is defined as followed: a TAPSE of &amp;lt;17 mm, an S’ of &amp;lt;9.5 cm, and an FAC of &amp;lt;35%. Results Among 49 patients, one patient showed a TAPSE of &amp;lt;17 mm, 5 patients an S’ of &amp;lt;9.5 cm, and 10 patients an FAC of &amp;lt;35%. Evaluating characteristics of Brs patients with RV dysfunction, all patients were divided into 2 groups by the value of RV FAC; 39 patients showing FAC &amp;gt;35% (group A), 10 patients FAC ≤35% (group B). The comparison of each parameter between 2 groups is shown in Table. TAPSE and S’ in group B were lower than in group A. RV inflow tract diameter in group B was larger than in group A, although there was no differences in RV out tract diameter. There were no significant differences in left ventricular parameters, and grade of tricuspid regurgitation. QRS duration prolonged and the rate of ICD implantation was higher in group B than in group A. Moreover, all patients in group B showed RV wall motion abnormalities and the distribution was as followed: diffuse (n = 2), RV mid (n = 2), RV apex (n = 6). Conclusions BrS patients frequently showed RV dysfunction during follow-up, and it may be related to the prolongation of QRS duration. We should pay much attention to the occurrence of RV dysfunction in follow-up echocardiography. Group A (FAC &amp;gt;35%) N = 39 Group B (FAC ≤35%) N = 10 p-value TAPSE, mm 22.9 ± 2.1 20.4 ± 2.6 0.009 S", cm/s 12.8 ± 2.0 11.1 ± 1.4 0.010 RV outflow tract, mm 29.7 ± 4.4 31.2 ± 5.0 0.49 RV mid inflow tract, mm 30.4 ± 2.9 33.8 ± 3.7 0.008 RV basal inflow tract, mm 38.5 ± 3.2 43.7 ± 4.0 0.001 QRS duration, ms 112.9 ± 12.9 136.3 ± 28.4 0.006 Late potential positive, n (%) 25 (64) 8 (80) 0.34 ICD implantation, n (%) 19 (68) 9 (90) 0.019

Assessment of the prognostic significance of low gradient severe aortic stenosis and preserved left ventricular function requires the integration of the consistency of stroke volume calculation and clinical data.

This study was to evaluate the prognostic significance of low gradient severe aortic stenosis (LG SAS) and preserved left ventricular ejection fraction (LVEF) with the integration of echocardiographic and clinical data. The study included 172 patients with LG SAS (AVAi≤0.6cm2 /m2 , mean aortic pressure gradient<40mmHg) and LVEF (≥ 50%). LV outflow tract diameters were measured at both the aortic valve annulus and 5mm below the annulus for the measurement consistency. Patients were divided into the low flow LG SAS (LF/LG SAS: SVi<35mL/m2 and AVAi≤0.6cm2 /m2 ) and normal-flow LG SAS groups (NF/LG SAS: SVi≥35mL/m2 and AVAi≤0.6cm2 /m2 ). Echocardiographic findings and clinical data were systematically analyzed with mean follow-up of 3.0±1.6years. LF/LG SAS had significantly smaller AVAi, lower SVi, a higher prevalence of atrial fibrillation (28% vs 12% P=.01) and diabetes (47% vs 27% P=.007) and lower 3-year cumulative survival than NF/LG SAS. Multivariable analysis showed that dyspnea, renal dysfunction (CI 1.42-3.99, P<.01), left atrial diameter, and SVi were independently associated with an increased risk for all-cause mortality. Aortic valve intervention (AVI) improved survival in LF/LG SAS (68% vs 48%, P<.05) in comparison with medical management (HR: 4.20, CI: 1.12-15.76, P=.03), but only modestly in NF/LG SAS (75% vs 65% P>.05). Outcome of LG SAS was independently associated with clinical characteristics. AVI likely improved outcome of LF/LG SAS who had high-risk clinical characteristics and unfavorable echocardiographic findings.

392 Practical Guide to Guard Against Underestimating 2D Left Ventricular Outflow Tract Diameter (LVOTd) Measurements in Bicuspid (BAVs) and Tricuspid (TAVs) Aortic Valves – Improving Aortic Valve Area (AVA) Calculations by Transthoracic Echocardiography (TTE)

392 Practical Guide to Guard Against Underestimating 2D Left Ventricular Outflow Tract Diameter (LVOTd) Measurements in Bicuspid (BAVs) and Tricuspid (TAVs) Aortic Valves – Improving Aortic Valve Area (AVA) Calculations by Transthoracic Echocardiography (TTE)

P670 RV function in adult patients with repaired tetralogy of Fallot: assessment by three-dimensional echocardiography, comparison to CMR findings and relationship to pulmonary artery distensibility

Abstract Purpose The purpose of this study was to examine right ventricular (RV) function by three-dimensional speckle-tracking echocardiography (3DSTE) in patients after correction of tetralogy of Fallot (TF), the accuracy of 3DSTE compared to cardiovascular magnetic resonance (CMR) findings and assess pulmonary arterial (PA) distensibility in order to achieve a more comprehensive understanding of the matching between RV performance and PA load. Methods Twenty-one patients (mean age 39 ± 16 years) with repaired TF and twenty-one age-matched healthy subjects selected as controls were studied. CMR findings were available in 14 patients. RV volumes, RV ejection fraction (RVEF) and RV longitudinal and circumferential strains were calculated by three-dimensional echocardiography and three-dimensional speckle tracking echocardiography. The main pulmonary artery was interrogated by color, pulsed, and continuous-wave Doppler. Pulmonary regurgitation (PR) was assessed by color-flow mapping and graded as none, mild, or greater than mild using the measurement of the regurgitant jet width in relation to the outflow tract diameter. Right pulmonary artery (PA) was visualized from suprasternal view by two-dimensional echocardiography. Tissue Doppler Imaging (TDI) mode was activated in B-mode imaging to examine arterial motion, then mode was changed to color-mode with the beam line aligned perpendicular to the superior and inferior walls of the right PA. PA distensibility and strain were determined. Data analysis was performed offline. Results Overall, 3D RVEF and RV longitudinal strain were reduced in TF patients compared to the control group. Nine patients had moderate or moderate-to-severe PR. PA strain and distensibility were decreased (p = 0.003) compared with controls, both in the presence and absence of PR. PA strain had a positive correlation with RVEF (r = 0.79, p &amp;lt; 0.005) and RV strain (r = 0.82, p &amp;lt; 0.001). RV end-diastolic and end-systolic volumes by 3DE correlated with the respective parameters by CMR (r = 0.88,p &amp;lt; 0.001 and r = 0.87,p &amp;lt; 0.005 respectively). Patients with moderate-to-severe PR had more prominent PA strain changes (p = 0.02). Conclusions Three-dimensional right ventricular ejection fraction and RV strain are impaired in patients with repaired TF, in agreement with CMR data. Reduced PA strain is associated with reduced RV 3DSTE parameters and is more pronounced in the presence of pulmonary regurgitation.

Determinants of Aortic Prosthesis Mismatch in a Brazilian Public Health System Hospital: Big Patients or Small Prosthesis?

BackgroundProsthesis-patient mismatch (PPM) is associated with worse outcomes.ObjectiveDetermine the frequency and evaluate preoperatory variables independently associated with severe PPM in a tertiary hospital focused on Public Health Care.MethodsA total of 316 patients submitted to aortic valve replacement, who had echocardiography performed within the first 30 days after surgery, were retrospectively analyzed. The indexed effective orifice area (iEOA) of the prosthesis was used to classify the patients into three groups, according to PPM, considering body mass index (BMI): severe PPM (iEOA) < 0.65 cm2/m2), mild to moderate PPM (iEOA, 0.65 cm2/m2 - 0.85 cm2/m2) and without PPM (iEOA > 0.85 cm2/m2) for a BMI < 30 kg/m2 and severe PPM (iEOA) < 0.55 cm2/m2), mild to moderate (iEOA, 0.55 cm2/m2- 0.70 cm2/m2) and without PPM (iEOA > 0.7 cm2/m2) for a BMI > 30 kg/m2. Statistical significance was considered when p < 0.05.ResultsiEOA was obtained in 176 patients. The frequency of severe and moderate PPM was 33.4% and 36.2%, respectively. Severe PPM patients were younger and had larger BMI, but smaller left ventricular outflow tract diameter (LVOTD). The independent variables used to predict severe PPM were male gender, BMI > 25 kg/m2, age < 60 years, LVOTD < 21 mm, and rheumatic etiology with an area under the ROC curve of 0.82.ConclusionThe frequency of severe PPM is high in a Brazilian population representative of the Public Health System, and it is possible to predict PPM from preoperative variables such as rheumatic valvular disease, gender, BMI, age and LVOTD.

104 Left ventricular stroke volume differences among echocardiographic methods in healthy adults from the World Alliance of Societies of Echocardiography (WASE) Normal Values Study

Abstract Funding Acknowledgements WASE Normal Values Study is sponsored by American Society Echocardiography Foundation. OnBehalf the WASE Investigators Background Left ventricular (LV) stroke volume (SV) can be determined by multiple ultrasound methods, including Doppler, two- (2D) and three-dimensional (3D) echocardiography. However, how methods compare to each other is not well understood. In this report from the WASE study, we aim to examine and compare normal reference ranges for SV and SV index (SVI) obtained from healthy adults by Doppler, 2D Simpson’s and 3D methods. Methods WASE Normal Values Study is a multinational, observational, cross-sectional study. Individuals free from known cardiac, lung and renal disease were prospectively enrolled with even distribution among age groups and gender. Doppler, 2D and 3D datasets were acquired at the enrolling centers, following a standardized protocol. LV SV was measured by three methods: Doppler (LV outflow tract diameter and velocity time integral), 2D biplane Simpson’s rule and 3D volume method. SV was indexed by body surface area (SVI). All measurements were analyzed (TOMTEC) in two core laboratories (for 2D and 3D) following ASE Guidelines. Methods were compared by Friedman test and Bland-Altman analysis. Results As of May 2019, 646 cases have been analyzed in both 2D and 3D datasets. In this population, age was 45 ± 16 years old (range 18-85) and body surface area was 1.76 ± 0.22 m² (range 0.95-2.44). LV EF by 2D Simpson’s rule and 3D method were 63.2 ± 2.9 and 62.3 ± 5.0 %, respectively (p &amp;lt; 0.0001, Wilcoxon test). SVI by Doppler, 2D and 3D were 39.6 ± 7.6, 33.8 ± 6.5 and 41.0 ± 9.4 ml/m², respectively. There were significant differences between the three methods (p &amp;lt; 0.0001, Friedman test). 2D underestimated SVI compared to Doppler by 14.6% (mean of differences 5.8 ml/m², p &amp;lt; 0.0001) and 3D by 17.6% (7.2 ml/m², p &amp;lt; 0.001). The difference between Doppler and 3D was smaller (3.4% lower by Doppler) but still statistically significant (1.4 ml/m², p = 0.0008). The results are shown in the figure. Conclusions Comparing 3 modalities in a large population of healthy individuals, SV and SVI are underestimated by 2D Simpson’s method. Given the large differences, combining 2D and Doppler or 3D measurements for hemodynamic calculations (such as regurgitant volumes and fraction) should be done with caution. Abstract 104 Figure.

P941 Evaluation of right ventricular contractile reserve with exercise stress echocardiography

Abstract INTRODUCTION Right ventricular (RV) contractile reserve reflects the ability of the RV to adapt to elevated afterload. RV functional response to exercise is challenging but could represent an important prognostic factor, especially in pulmonary arterial hypertension (PAH) patients. We aimed, using exercise stress echocardiography (ESE), to assess different RV contractile reserve evaluation methods in a cohort of PAH patients and controls. METHODS We prospectively included 12 patients with PAH and 12 healthy volunteers. An ESE (using tilt-table ergometer) was performed in all patients to assess RV function at rest and under peak exercise. Changes in these parameters during exercise were calculated to quantify the RV contractile reserve. 3D RV function as well as peak systolic strain, pulmonary pressures, TAPSE, pulmonary TVI and pulmonary output (using the right ventricular outflow tract diameter) were assessed in all patients. RESULTS Our patient group was composed by PAH patients, 61.5 ± 14.8 years; mean age of our control group was 29.33 ± 5.5 years. PAH patients achieved an exercise with a mean workload of 69.17 ± 26.4 Watts. There was no complication after the exercise test in all patients. Change in TAPSE was not significantly different between patients and controls (p = 0.17), whereas change in pulmonary TVI, pulmonary output and RV peak systolic strain was highly discriminant (respectively p = 0.03, p = 0.009 and p = 0.0009). Regarding RV contractile reserve parameters, RV end-systolic pressure area ratio (peak/rest) was not statistically different between controls and patients (p = 0.14) whereas change in TAPSE/sPAP, RV peak strain/sPAP, 3D RV EF/sPAP were significantly different (p = 0.005, p= 0.0008, p = 0004). CONCLUSION Changes in pulmonary output, RV peak systolic strain as well as changes in TAPSE/sPAP but mainly RV peak strain/sPAP, 3D RV EF/sPAP represent consistent and feasible tools to assess RV contractile reserve. echocardiographic parameters PAH (n = 12) Healthy Controls (n = 12) p value sPAP at rest (mmHg) 40.91 ± 10.7 15.42 ± 4.1 &amp;lt;0.001 sPAP at peak (mmHg) 82.50 ± 21.7 42.50 ± 17.8 &amp;lt;0.001 TAPSE at rest/sPAP at rest (mm/mmHg) 0.62 ± 0.2 1.72 ± 0.6 &amp;lt;0.001 TAPSE at peak /sPAP at peak 0.36 ± 0.1 0.80 ± 0.2 &amp;lt;0.001 ΔStrain (%) 3.43 ± 3.1 8.08 ± 2.8 &amp;lt;0.001 Δ(peak Strain/sPAP) -0.17 ± 0.2 -0.77 ± 0.4 &amp;lt;0.001 Δpulmonary TVI (cm) 3.88 ± 4.0 7.46 ± 3.5 0.03 Δ(RVEF/sPAP) -0.34 ± 0.4 -2.06 ± 1.7 &amp;lt;0.001 Abstract P941 Figure. echography (rest/peak) PAH patient

Evaluation of right ventricular contractile reserve with exercise stress echocardiography

Right ventricular (RV) contractile reserve reflects the ability of RV to adapt to elevated afterload. RV functional response to exercise is challenging but could represent an important prognostic factor, especially in pulmonary arterial hypertension (PAH) patients. To assess different RV contractile reserve evaluation methods in a cohort of PAH patients and controls, using exercise stress echocardiography (ESE). We prospectively included 12 patients with PAH and 12 healthy volunteers. An ESE (using tilt-table ergometer) was performed in all patients to assess RV function at rest and under peak exercise. Changes in these parameters during exercise were calculated to quantify the RV contractile reserve. 3D RV function as well as peak systolic strain, pulmonary pressures, TAPSE, pulmonary VTI and pulmonary output (using the right ventricular outflow tract diameter) were assessed in all patients. Our patient group was composed by PAH patients, 52 ± 11 years; mean age of our control group was 31 ± 6 years. PAH patients achieved an exercise with a mean workload of 70 ± 26.4 Watts. There was no complication after the exercise test in all patients. Change in TAPSE was not significantly different between patients and controls ( P = 0.17), whereas change in pulmonary VTI, pulmonary output and RV peak systolic strain was highly discriminant (respectively P = 0.03, P = 0.009 and P = 0.0009). Regarding RV contractile reserve parameters, RV end-systolic pressure area ratio (peak/rest) was not statistically different between controls and patients ( P = 0.14) whereas change in TAPSE/sPAP, RV peak strain/sPAP, 3D RV EF/sPAP were significantly different ( P = 0.005, P = 0.0008, P = 0004). Changes in pulmonary output, RV peak systolic strain as well as changes in TAPSE/sPAP but mainly RV peak strain/sPAP, 3D RV EF/sPAP represent consistent and feasible tools to assess RV contractile reserve.

Measurement errors in serial echocardiographic assessments of aortic valve stenosis severity.

Transthoracic echocardiography (TTE) evaluation of aortic stenosis (AS) is routinely performed using the continuity equation. Inaccurate measurements of the left ventricular (LV) outflow tract (LVOT) diameter are considered the most common source of error in AS grading. We hypothesized that inconsistency in LVOT velocity time integral (VTI) is an under-recognized cause of AS assessment error. We sought to determine which parameters contribute most towards inconsistencies in AS grading by studying the prevalence of different errors in a historic cohort. We identified patients with mild to severe AS with multiple studies from our database from 1994 to 2018 (n = 988 patients, 2859 studies). Errors were defined when: (1) LVOT diameter changed by > 2mm, (2) LVOT VTI changed by > 15% without change in LV function from the initial TTE, (3) aortic valve (AV) maximum velocity (Vmax), mean pressure gradient (ΔP) or AV VTI decreased by > 15% without change in LV function from prior study. The most common error was the LVOT VTI measurement with 22% prevalence. LVOT diameter, AV VTI, AV Vmax and AV ΔP measurement caused errors in < 7% studies. Patients with normal LV function and more severe AS were more likely to have LVOT VTI errors (P < 0.05). LVOT VTI is a frequent, under-recognized source of error in assessing AS. Greater attention should be directed toward the proper positioning of the pulsed Doppler sample volume, particularly in patients with higher grades of AS and normal systolic function, to ensure accurate and reproducible assessment of AS.

The possibilities of echocardiography of the right heart chambers

The possibilities of modern echocardiography in the right heart chambers assessment are disclosed. The most novel methods of measurement and standards of sizes of the right heart chambers, parameters of systolic and diastolic function using quantitative three-dimensional echocardiography and myocardial strain are discribed. It was mentioned that echocardiographic estimation of the right heart chambers is of the same great significance as the assesment of the left ones, but is complicated due to anatomic and functional features. It demanded some steps for create and validate the right atrium and ventricle linear and volume parameters, right ventricle systolic and diastolic function and its normal values. So, contemporary echo-protocol would contain right ventricle basal and median sizes, proximal and distal right ventricle outflow tract diameters, right atrium volume index. For assessment of the right ventricle systolic function the combined using of following markers is recommended: fractional area change, tricuspid annulus systolic excursion, systolic myocardial velocity, myocardial performance index. Special technologies of modern ultrasound equipment allows to determine the most effective parameters, such as 3D volumes, 3D ejection fraction and right ventricle global longitudinal strain.

Performance of the right ventricular outflow tract/aortic diameter as a novel predictor of risk in patients with acute pulmonary embolism.

Right ventricular (RV) enlargement, determined via the ratio of the right to left ventricular diameters (RV/LV) by CT imaging is used to classify the severity of acute pulmonary embolism (PE) and impacts treatment decisions. The RV/LV ratio may be an unreliable marker of RV dysfunction, due in part to the complex RV geometry. This study compared the RV/LV ratio to a novel metric, the ratio of the right ventricular to aortic outflow tract diameters (RVOT/Ao) in patients with acute PE treated with catheter-directed therapies (CDT). RVOT/Ao and RV/LV ratios were measured on CT images from 103 patients who received CDT for acute submassive or massive PE and were compared to RV dysfunction severity determined by transthoracic echocardiography. Ratios and biomarkers on admission were assessed for correlation with invasively-measured hemodynamics [right atrial (RA) pressure, mean pulmonary artery (PA) pressure, cardiac output (CO)]. RVOT/Ao but not RV/LV ratios were increased in patients with moderate or severe RV dysfunction compared to those without RV dysfunction (p < 0.05). Neither ratio showed significant correlation with RA (r = 0.09 vs 0.055, p > 0.05), mean PA pressure (r = 0.167 vs 0.146, p > 0.05), or CO (r = 0.021 vs - 0.183, p > 0.05). proBNP correlated with mean PA pressure (r = 0.377, p < 0.05). The RVOT/Ao ratio may be better at assessing RV dysfunction than the RV/LV ratio in patients presenting with acute PE. Although currently accepted protocols rely on the RV/LV ratio in determining when CDT are of benefit, the RVOT/Ao ratio may be a more useful tool in identifying high risk patients.

Validation of Epworth Richmond's Echocardiography Education Focused Year.

OBJECTIVES: College of Intensive Care Medicine mandatory training in echocardiography requires a minimum 30 echocardiograms. Trainee echocardiography accuracy following mandatory training is unknown. Our objective was to determine the reliability of ICU trainee echocardiography after our yearlong College of Intensive Care Medicine accredited course. DESIGN: Single-center, prospective observational study. Trainee echocardiograms were compared to independent, blindedexpert echocardiograms, with a target of 37 matched scans per trainee. SUBJECTS: Trainees were eligible to participate on completion of our in-house, mandatory echocardiography training. SETTING: Epworth Richmond is in an Australian, private academic hospital with a critical care echocardiography teaching program. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Reliability was assessed on nine measurements. The primary outcome was agreement on left ventricular function; secondary outcomes included qualitative and quantitative assessments. Agreement was assessed using Cohen's kappa, Fleiss-Cohen weighted kappa, Lin's concordance correlation coefficient, or calculation of sensitivity and specificity as appropriate. Seven trainees performed a total of 270 matched scans. There was excellent agreement between experts and trainees for left ventricular function (Kappa, 0.86; 95% CI, 0.81-0.91). Secondary outcome measures (95% CI) were ventricular size ratio Kappa 0.76 (0.58-0.94), sensitivity 92.3% (64.0-99.8%), specificity 97.2% (94.9-99.1%), pericardial effusion Kappa 0.37 (0.13-0.60), sensitivity 33.3% (13.3-59.0%), specificity 97.6% (94.8-99.1%). Concordance coefficients (95% CI) for the remaining outcomes were left ventricular outflow tract velocity time integral 0.79 (0.74-0.84), left ventricular internal diameter in diastole 0.82 (0.78-0.86), left ventricular outflow tract diameter 0.61 (0.53-0.69), tricuspid annular plane systolic excursion 0.71 (0.64-0.78), tricuspid regurgitation maximum velocity 0.55 (0.44-0.65), and inferior vena cava diameter 0.60 (0.49-0.72). CONCLUSIONS: ICU trainees showed very high overall agreement with experts on left ventricular function and substantial agreement for most secondary outcomes. This is the first study to assess echocardiography accuracy in Australian ICU trainees.

P4371Right ventricular remodeling during the first weeks of life in healthy neonates

Abstract Background The right ventricle (RV) serves as the dominant ventricle in utero. The transition from fetal to post-natal circulation at birth involves marked structural and functional cardiac changes including a large increase in pulmonary blood flow and closure of fetal shunts. Little is known about how the transitional circulation influences RV structure and function in healthy neonates during the first weeks of life. The purpose of this study was to systematically assess RV remodeling in a large, unselected cohort of healthy neonates. Methods Transthoracic echocardiograms of unselected neonates &lt;26 days old without any signs of structural cardiac abnormalities performed between April 1st, 2016 and August 12th, 2017, were consecutively included from the Copenhagen Baby Heart study until at least 90 neonates per day were included. Left parasternal long-axis RV anterior end-diastolic wall thickness and short-axis RV outflow tract end-diastolic diameter were measured offline by one sonographer according to recommendations by the American Society of Echocardiography. RV parameters were corrected for body surface area (BSA). Comparisons were made by T-tests and correlations were computed using univariate linear regression. Results A total of 3,412 echocardiograms were assessed, of which 414 were excluded due to age ≥26 days (n=159), presence of cardiac abnormality (n=179), or suboptimal parasternal views (n=76). Thus, a total of 2,998 (48% male) were included for analysis. Age, weight, and length at examination were (mean±SD) 11.1±7.5 days, 3.6±0.6 kg, and 52±2.6 cm, respectively. BSA-corrected mean (95% CI) end-diastolic outflow tract diameter and end-diastolic anterior wall thickness according to age are presented (Figure). There was a small age-related reduction in end-diastolic RV outflow tract diameter (r2=0.018, p&lt;0.001), whereas the BSA-corrected end-diastolic anterior wall thickness decreased by 35% (from 14.2 to 9.2 mm/m2, p&lt;0.001) from birth to day 25. Figure 1. Mean (95% CI) BSA-corrected end-diastolic RV anterior wall thickness and end-diastolic RV outflow tract diameter. P-value for correlation. Conclusion RV remodeling during the first 25 days of life in unselected neonates included a small decrease in RV outflow tract diameter and a 35% decrease in anterior wall thickness.

P910An Asian perspective on left ventricular outflow tract cut-offs and the resulting discrepancy in severity grading of aortic stenosis

Abstract Objectives Inconsistencies in grading of aortic stenosis (AS) severity have been reported based on measurement of left ventricular outflow tract diameter (LVOTd), but this remains to be studied in an Asian population. We investigated consistency of grading AS severity at various LVOTd, and subsequently postulated alternative cut-offs for more consistent grading of AS severity. Methods 350 consecutive patients with index echocardiographic diagnosis of severe AS were divided them into three groups based on LVOTd: “small” (&lt;20mm), “average” (20–22mm), “large” (&gt;22mm). In each group, the consistency of flow-dependent (transaortic mean pressure gradient (MG)) and flow-independent parameters (AVA) were used for classification of AS severity. Results Of 350 patients, 51.7% had small LVOTd, while 30.8% and 17.5% had average and large LVOTd respectively. Consistent grading by LVOTd based on AVA and MG, was seen in 33.7% of patients with small, 47.6% with average, 57.7% with large LVOTd. When the hypothetical AVA cut-off of 0.9cm2 was used, consistent grading improved to 38.0% in small, 56.5% in average and 70% in large LVOTd. At an AVA cut-off of 0.8cm2, there was further incremental improvement in the small LVOTd group to 54.1% (p&lt;0.05). Table 1. Consistent grading by LVOTd based on current guidelines Small LVOTd (&lt;20mm, n=181) Average LVOTd (20–22mm, n=108) Large LVOTd (&gt;22mm, n=61) Consistent grading AVA &lt; cut-off MG &gt;40 Consistency (%) Consistent grading AVA &lt; cut-off MG &gt;40 Consistency (%) Consistent grading AVA &lt; cut-off MG &gt;40 Consistency (%) n=61 33.7 n=51 47.6 n=35 57.7 n=69 38 n=61 56.5 n=43 70* n=98 54.1*+ n=70 65.1* n=43 70.8* *p-value &lt;0.05 when compared with AVA cut-off 0.8cm2 for each LVOTd category; +p-value &lt;0.05 when compared with AVA cut-off 0.9cm2 for each LVOTd category. Figure 1 Conclusion Current severe AS guidelines are most consistent with those in the large LVOTd group. However, the majority of the study's Asian population is in the small LVOTd group, which is the group most susceptible to discrepancy in AS grading. Improved consistency in echocardiographic grading may be attained with a lower AVA cut-off in this Asian cohort.

P4507Left atrial conduit function modulates functional capacity in heart failure patients acting through the pulsatile component of right ventricular afterload

Abstract Background It has been suggested that left atrial (LA) characteristics modulate the functional capacity in heart failure (HF) patients through the impact that LA cavity exerts on the pulmonary circulation and the pulsatile component of right ventricular (RV) afterload, as represented by pulmonary arterial compliance (PAC). Purpose Thus, we hypothesized that, in a HF patients' population, a larger relative contribution of LA phasic conduit function (PCF) to the left ventricular (LV) stroke volume would be associated with a heavier right ventricular hemodynamic burden and a reduced functional capacity. Methods 60 sinus rhythm HF subjects (42 males, 67±11 years, ejection fraction [EF] 39±11%, range 20% - 62%) underwent 6 minute walking test (6MWT) and routine transthoracic echocardiography, plus real time 3D acquisitions analyzed with a dedicated echo software package. LV ejection fraction (EF) was obtained from 3D echo acquisitions. LV diastolic dysfunction (DD) was assessed according to current guidelines. Computation of PCF was made by simultaneous gathering real time 3D multibeats (6 cycles) LA and LV volumes, using the formula: PCF(time) = [LV(time) − LV minimum] − [LA maximum − LA(time)] as proposed by Bowman &amp; Kovacs (2004), with PCF expressed as % of LV stroke volume. Atrioventricular compliance (Cn) was also assessed, as proposed by Flachskampf et al. (1992): 1270*(mitral valve area/E wave downslope) and expressed in ml/mmHg. Finally, PAC was obtained as the ratio between RV stroke volume (pulmonary velocity time integral*pulmonary valve annulus area measured from the RV outflow tract diameter) and pulse pressure (obtained from pulmonary and tricuspid regurgitant envelopes) and expressed in ml/mmHg. Results Maximal LA and LV volumes averaged 69±21 ml and 147±47 ml, respectively. The mean value of PCF was 33±12% (range 7% - 58%). Mean 6MWT was 397±162 m. Mean PAC was (3.1±1.1 ml/mmHg). DD grade I, II and III were detected in 38 (63%), 18 (30%) and 4 (7%) of the patients' population, respectively. PCF was independent of LA or LV volumes and EF, but showed a strong direct relation with DD (r=0.62; p&lt;0.0001) and a relevant inverse dependence on Cn (r=−0.48; p=0.0001). For a comparable Cn, dividing patients into tertiles according to 6MWT, it was clear that highest PCF was significantly associated with lowest functional capacity (ANCOVA, figure left). Similarly, dividing patients into tertiles according to PAC, it emerges that highest PCF is significantly associated with most deranged PAC (ANCOVA, figure right), suggesting outmost RV hemodynamic burden. Conclusion PCF is an important parameter to be quantified in HF patients that is dependent on global left heart compliance, being affected by DD, but not LV EF. Furthermore, at a given Cn, PCF is increased in HF patients with lowest functional capacity, likely because RV pulsatile afterload is highest in these subjects.

P4359Re-characterising the left ventricular outflow tract and annulus in bi- and tricuspid aortic valves by 3D echocardiography - Comparative insights and implications for aortic valve area calculations

Abstract Background Aortic stenosis severity is defined by the calculated aortic valve area (AVA) using the Doppler-derived continuity equation (CE; AVACE = 0.785 x (LVOTd)2 x LVOT VTI/AV VTI (LVOTd = left ventricular outflow tract diameter; AV = aortic valve; VTI = velocity-time integral)). The LVOTd is the “Achilles heel” due to limitations of conventional 2D imaging and unstandardized measurement sites (0.5–1cm “apical” in the LVOT (LVOTdApi) vs “annulus” level (LVOTdAnn)) with no consensus even in recent guidelines. Geometrical differences in the LVOT and annulus of bicuspid (BAV) and tricuspid (TAV) aortic valves are further confounders. There remains a paucity of evidence to guide best practice. Erroneous LVOTd values will result in inaccurate AVACE estimations, triggering inappropriate intervention, or inaction. Purpose To define the optimal LVOTd by transthoracic echocardiography (TTE; LVOTdApi vs LVOTdAnn by 2D vs 3D) for AVACE calculation, and to identify factors accounting for any observed differences between BAVs and TAVs. AVA measured by 3D TTE planimetry (AVA3D) was the reference standard. Methods TTEs with 3D datasets of the AV complex in patients with BAVs and TAVs were included. 2D-LVOTdApi and 2D-LVOTdAnn were measured from 2D parasternal long-axis images. 3D-LVOTd values were calculated from the measured circumference, area, and average of minor/major dimensions at the “apical” (3D-LVOTdApi-Circ; 3D-LVOTdApi-Area; 3D-LVOTdApi-Ave) and “annulus” (3D-LVOTdAnn-Circ; 3D-LVOTdAnn-Area; 3D-LVOTdAnn-Ave) levels using multiplanar reconstruction. LVOTVTI and AVVTI were traced from standard spectral Doppler waveforms. The ratio of minor:major dimensions was used as an eccentricity index (EI) of the “apical” (EIApi) and “annulus” (EIAnn) sites. Results 53 BAVs and 52 TAVs were included. Mean BAV-AVA3D and TAV-AVA3D were 3.48±0.93cm2 and 3.41±0.69cm2 respectively. In BAVs, estimated AVACE using 3D-LVOTdApi-Circ (3.43±1.05cm2; Intraclass correlation (ICC) 0.971) and 3D-LVOTdAnn-Circ (3.40±1.01cm2; ICC 0.968) correlated best with AVA3D. Conversely in TAVs, 3D-LVOTdApi-Area (3.29±0.69cm2; ICC 0.983) and 3D-LVOTdAnn-Area (3.24±0.70cm2; ICC 0.975) performed optimally. 3D-LVOTdApi-Circ and 3D-LVOTdAnn-Circ overestimated TAV-AVA3D due to the greater ellipticity of the “apical” and “annulus” sites in TAVs (TAV vs BAV: EIApi 0.78 vs 0.83, P=0.04; EIAnn 0.84 vs 0.90, P&lt;0.005). 2D-LVOTd-derived AVACE were predictable underestimations of the AVA3D but the “annulus” level outperformed “apical” in both BAVs and TAVs (BAV-ICC 0.857 vs 0.771; TAV-ICC 0.917 vs 0.889). Conclusions The “apical” LVOT and “annulus” are more circular in BAVs where 3D circumference (3D-LVOTdApi-Circ or 3D-LVOTdAnn-Circ) yielded the best AVACE. The more elliptical geometry in TAVs resulted in 3D area (3D-LVOTdApi-Area or 3D-LVOTdAnn-Area) the preferred technique. Resolving the quandary of measurement site, 2D-LVOTdAnn is favored over 2D-LVOTdApi for both BAVs and TAVs.

Evaluation of the Effect of Sigmoid-Shaped Interventricular Septum on Left Ventricular Systolic Function in Patients with Essential Hypertension by Two-Dimensional Speckle Tracking Echocardiography

Objective: To evaluate left ventricular regional and global systolic function by measuring left ventricular longitudinal strain (LS) in hypertensive patients with sigmoid-shaped interventricular septum (SIS) by two-dimensional speckle tracking (2D-STE); in order to explore whether the sigmoid-shaped interventricular septum affects the left ventricular systolic function in patients with hypertension. Methods: Routine echocardiographic parameters were measured in 30 hypertensive patients with SIS (SIS group) and 30 hypertensive patients without SIS (non-SIS group). The left ventricular segments and global LS were measured by 2D-STE, and the two sets of parameters were compared. Results: The value of the thickness of the basal segment of the interventricular septum (IVSBT), the thickness of the middle segment of the interventricular septum (IVSMT) and the ratio of the basal segment of the ventricular septum to the middle segment of the interventricular septum (IVSBT/IVSMT) in SIS group was higher than that in non-SIS group. However, the value of left ventricular outflow tract diameter (LVOTD) in SIS group was lower than that in non-SIS group. There was a significant difference between the two groups (all P < 0 05). The LS values of the basal segment of the left ventricular anterior wall and the posterior wall of the left ventricle in the SIS group were lower than those in the non-SIS group. The difference was statistically significant (all P < 0.05). Conclusion: SIS affects left ventricular regional systolic function of patients with hypertension. 2D-STE can early evaluate left ventricular longitudinal systolic function in hypertensive patients with SIS.

Pure Aortic Regurgitation in Pediatric Patients

Aortic regurgitation (AR) continues to be an important cause of morbidity and mortality in pediatric patients. Although echocardiographic parameters are well established for the adults, there are no clear cut-off values for AR severity in children. Cardiac magnetic resonance (CMR) imaging is considered a "gold standard" for a quantitative evaluation of the AR, but it is not widely available. This study assesses which echo parameter can accurately define AR severity as assessed by CMR in pediatric patients. A total of 27 pediatric patients (12 ± 3 years, range 6 to 18 years) with different degree of AR underwent echo assessment within an average of 35 days from CMR. CMR included phase-contrast velocity-encoded imaging for the measurement of regurgitant fraction (RF). Severe AR was defined as RF >33%. Echo evaluation included vena contracta, pressure half time, the ratio between the AR jet and the left ventricular outflow tract diameter (jet/left ventricular outflow tract), presence of holodiastolic reversal flow in abdominal aorta, the ratio between the velocity-time integral of the reversal flow over the forward flow in descending aorta (echoRF). Among the studied parameters, the strongest predictor of severe AR, as assessed by CMR, was echoRF. Receiver-operating characteristic curve showed, for a cutoff >0.38, an area under the curve of 0.886 (p <0.0001), a sensitivity of 71%, and a specificity of 100%. Correlation coefficient between echoRF and RF was R = 0.929 (p <0.0001). In conclusion, echoRF is a strong echo-Doppler marker of severe AR in the pediatric population. This parameter should be routinely added in the standard echo evaluation of pediatric patients with AR.

Factors predicting persistence of AV nodal block in post‐TAVR patients following permanent pacemaker implantation

A common complication of transcatheter aortic valve repair (TAVR) is development of conduction defects requiring pacemaker (PPM) implantation. These defects are not universally permanent. To determine the incidence and predictors of persistent device dependency in patients with PPM implantation following TAVR with a self-expanding prosthesis. Records of patients who underwent post-TAVR PPM implantation were reviewed. Patients with persistent complete AV block (AVBIII) one month post-TAVR were compared to those regaining conduction. Between September 2014 and March 2017, 485 patients underwent TAVR with a self-expanding prosthesis; 77 (15.9%) underwent PPM implantation for AVBIII. Device interrogation at one month was available for 61 patients (79%): 22 (36.1%) had resolution of AVBIII while 39 (63.9%) remained pacemaker-dependent. Pre-TAVR right bundle branch block was more frequent in device-dependent patients (19 of 38, 50% vs 4 of 22, 18%; RR 2.75; P=.01). Device-dependence was associated with AVBIII as the first postprocedural rhythm (37 of 39, 95% vs 12 of 22, 55%; RR 1.74; P<.0001), earlier implantation (median 1d, IQR: 0-1.5d vs 2d, IQR: 1.0-4.0d, P=.0004), and a shorter duration of hospitalization (median 3d, IQR: 2-3.5d vs 4d, IQR: 2-5.75d, P=.03). Pacemaker dependence was also associated with a higher prosthesis-to left ventricular outflow tract (LVOT) diameter (1.45 ± 0.11vs 1.39 ± 0.07; P=.02) and the lack of prior aortic valvuloplasty (5 of 39, 13%vs 8 of 22, 36%; RR 0.35; P=.03). In patients receiving a PPM following self-expanding TAVR, a long-term pacing requirement can be predicted from the timing of AV block, existing conduction-system disease, larger prosthesis-to-LVOT diameter, and the lack of aortic valvuloplasty.