Annulus Distance Research Articles

Ultra-high-resolution CT of the temporal bone before cochlear implantation for pre-operative prediction of chorda tympani nerve management and round window access.

To evaluate various anatomical parameters and their relationship to chorda tympani nerve (CTN) injury and round window (RW) access during cochlear implantation. Ultra-high-resolution CT images of 66 patients were retrospectively reviewed and compared with operative reports. The facial recess and the round window were analyzed, mainly using the chorda-facial angle (CFA), the width of the facial recess, the CTN-tympanic annulus distance, the RW-mastoid portion of the facial nerve angle, and the type of RW. Surgical management of the CTN was uneventful in 59 patients, whereas surgical difficulty occurred in 7, with significant differences only between the CTN-tympanic annulus distance and the RW-mastoid portion of the facial nerve angle (P ≤ 0.04). The optimal cut-off values for predicting surgical difficulty were 0.95mm and 19°, respectively, with sensitivity, specificity, positive, and negative predictive values of 0.71, 0.67, 0.2 and 0.95 for the distance, and 0.57, 0.95, 0.57 and 0.94 for the angle, respectively. The RW was accessible in 51 patients and cochleostomy was performed in 15 patients, without significant difference between radiological parameters, especially concerning the CFA. A CTN-tympanic annulus distance greater than 0.95mm may help to predict a non-negligible risk of CTN surgical damage, and a RW thinner than 1.85mm may require exploring the possibility of a cochleostomy approach.

Comparative study on melting and solidification processes of vertical shell-and-tube phase change heat exchanger with an improved conical inner tube

Comparative study on melting and solidification processes of vertical shell-and-tube phase change heat exchanger with an improved conical inner tube

Modeling of the Tricuspid Valve and Right Ventricle in Hypoplastic Left Heart Syndrome With a Fontan Circulation.

In hypoplastic left heart syndrome, tricuspid regurgitation (TR) is associated with circulatory failure and death. We hypothesized that the tricuspid valve (TV) structure of patients with hypoplastic left heart syndrome with a Fontan circulation and moderate or greater TR differs from those with mild or less TR, and that right ventricle volume is associated with TV structure and dysfunction. TV of 100 patients with hypoplastic left heart syndrome and a Fontan circulation were modeled using transthoracic 3-dimensional echocardiograms and custom software in SlicerHeart. Associations of TV structure to TR grade and right ventricle function and volume were investigated. Shape parameterization and analysis was used to calculate the mean shape of the TV leaflets, their principal modes of variation, and to characterize associations of TV leaflet shape to TR. In univariate modeling, patients with moderate or greater TR had larger TV annular diameters and area, greater annular distance between the anteroseptal commissure and anteroposterior commissure, greater leaflet billow volume, and more laterally directed anterior papillary muscle angles compared to valves with mild or less TR (all P<0.001). In multivariate modeling greater total billow volume, lower anterior papillary muscle angle, and greater distance between the anteroposterior commissure and anteroseptal commissure were associated with moderate or greater TR (P<0.001, C statistic=0.85). Larger right ventricle volumes were associated with moderate or greater TR (P<0.001). TV shape analysis revealed structural features associated with TR, but also highly heterogeneous TV leaflet structure. Moderate or greater TR in patients with hypoplastic left heart syndrome with a Fontan circulation is associated with greater leaflet billow volume, a more laterally directed anterior papillary muscle angle, and greater annular distance between the anteroseptal commissure and anteroposterior commissure. However, there is significant heterogeneity of structure in the TV leaflets in regurgitant valves. Given this variability, an image-informed patient-specific approach to surgical planning may be needed to achieve optimal outcomes in this vulnerable and challenging population.

Percutaneous reduction of septal-to-lateral mitral annular distance to increase mitral leaflet coaptation length: Preclinical study results.

Percutaneous indirect annuloplasty has emerged as a treatment strategy for functional/ischemic mitral regurgitation. This study sought to evaluate the feasibility of percutaneous indirect annuloplasty technique using a new device. The device has 3 components: the "saddle" inserted into the great cardiac vein, the "plug" positioned in the left ventricular outflow tract, and the "bridge," a transatrial suture connecting the 2 holding elements. The aim was to shorten the septal-to-lateral distance of the mitral annulus by pulling on the saddle element. The procedure was performed through venous access in healthy adult sheep. A dedicated catheter holding a needle was used to deploy the saddle into the great cardiac vein and pierce its wall toward the left atrium to deploy the expanded polytetrafluoroethylene suture that is part of the bridge. A catheter for transseptal puncture was inserted for crossing the interatrial septum and piercing the aortic-mitral curtain, thereby allowing the plug to be deployed. The plug was held in place by the second part of the expanded polytetrafluoroethylene bridge. The 2 parts of the bridge were then joined to reduce the septal-to-lateral mitral annular distance. The septal-to-lateral distance and the coaptation length at P2 level were measured before and after the procedure using echocardiography. Overall, 10 animals were treated, 7 successfully. The mean procedure duration was 110±81minutes. Septal-to-lateral distance decreased from 3.8mm to 2.6mm (30%), and maximum increase of mitral leaflet coaptation was 4mm. This new approach seems promising for percutaneous treatment of functional mitral regurgitation.

Simulation study on charging performance of the latent energy storage heat exchanger with a novel conical inner tube

The application of a latent heat thermal energy storage (LHTES) system can effectively solve the problem of the mismatch between the energy supply and demand. However, most studies focus on the traditional cylindrical configuration with a low heat storage rate, which limits the wide application of LHTES systems. The configuration optimization of a vertical shell-and-tube LHTES unit is carried out in this paper to enhance heat storage rate, and the effects of cone angle values (0–10°) in the conical shell and conical tube configurations on the heat storage performance are explored by numerical simulations. The results show that these two kinds of conical configurations both significantly improve the melting rate of the phase change material (PCM) compared with the cylindrical unit. However, when the cone angle is the same, the heat transfer enhancement effect of the latter is found to be superior to that of the former. Moreover, the complete melting time is shortened by 46 % as the cone angle of the inner tube increases from 0° to 10°. More importantly, a novel conical tube configuration design is proposed to eliminate the hard-to-melt zone at the bottom of the LHTES unit with the conical tube, then the effects of different tilting heights (60–170 mm) and bottom annulus distances (0–10 mm) are investigated. The results demonstrate that the melting rate increases with the increase in the tilting height, but the increased amplitude of that gradually reduces. Besides, the average heat storage rate shows a trend of first increasing and then decreasing with the increase in the distance of the bottom annulus. When the bottom annulus distance is 2 mm, the average heat storage rate reaches the maximum value, which is 94.84 W. The research results can provide a reference for the engineering design and configuration optimization of the vertical shell-and-tube phase change heat exchanger.

Changes in left ventricular geometry after subannular repair in type IIIb functional mitral regurgitation.

Papillary muscle repositioning in functional mitral regurgitation (FMR) alleviates mitral valve (MV) tenting by reducing the distance between papillary muscle tips and MV annular plane, i.e. apical left ventricular (LV) displacement. We aimed to quantify the effect of papillary muscle repositioning on papillary muscle geometry and to evaluate whether improved papillary muscle geometry after papillary muscle repositioning translates into the global LV reverse remodelling in FMR type IIIb. Patients with severe FMR type IIIb were prospectively enrolled and underwent pre- and postoperative 1.5-T cardiac magnetic resonance imaging. A new variable was defined, the papillary muscle to mitral annulus distance, which quantifies the distance between papillary muscle tips and MV annular plane. All parameters were measured by 2 independent investigators. A total of 63 patients were enrolled. In all patients, papillary muscle to mitral annulus distance correlated significantly with established markers of LV remodelling and MV tenting severity. In patients who underwent subannular papillary muscle repositioning procedure (surgical cohort, n = 23), preoperative median papillary muscle to mitral annulus distance was 30 mm [interquartile range (IQR): 27-34 mm] and was significantly reduced postoperatively to 25 mm (IQR: 21-27 mm) (P = 0.001). LV end-diastolic diameter was reduced from 66 mm (IQR: 60-71) preoperatively to 58 mm (IQR: 53-67) after the surgery (P = 0.001). MV repair with papillary muscle repositioning results in a papillary muscle to mitral annulus distance reduction and significantly improved MV tenting parameters. Improved papillary muscle geometry after papillary muscle repositioning is associated with a global LV reverse remodelling and may, thereby, improve the prognosis of FMR patients.

The impact of cardiac loading on a novel metric ofleft ventricular diastolic function in healthy middle-aged adults: Systolic-diastolic coupling.

AimsLeft ventricular (LV) restoring forces are primed by ventricular deformation during systole and contribute to cardiac relaxation and early diastolic suction. Systolic–diastolic coupling, the relationship between systolic contraction and diastolic recoil, is a novel marker of restoring forces, but the effect of left atrial pressure (LAP) is unknown. We tested preliminary methods of systolic–diastolic coupling comparing mitral annular velocities versus excursion distances and hypothesized a recoil/contraction distance ratio would remain unaffected across varying LAP, providing a surrogate for quantifying LV restoring forces.Methods and ResultsHealthy subjects (n = 61, age 52 ± 5 years) underwent manipulation of LAP with lower body negative pressure (LBNP) and rapid normal saline (NS) infusion. Pulmonary capillary wedge pressure (PCWP; pulmonary artery catheter) and tissue Doppler imaging of the mitral annulus were measured. Two models of systolic–diastolic coupling––early diastolic excursion (EDexc)/systolic contraction (Sexc) distances and e’/systolic (s’) velocities were compared. Velocity (e’/s’) coupling ratios varied significantly (mean e’/s’, slope = 0.022, p < 0.001) in relationship with PCWP (5–20 mmHg). Excursion (EDexc/Sexc) coupling ratio did not vary in relationship with PCWP (EDexc/Sexc: slope = −0.001, p = 0.19).Conclusions Systolic–diastolic coupling using mitral annular distance ratios to standardize early diastolic recoil to systolic contraction was not significantly impacted by LAP, in contrast to coupling ratios using velocities. The pressure invariance of annular distance coupling ratios suggests this metric quantifies the efficiency of LV restoring forces by isolating systolic contributions to early diastolic restoring forces independent from changes in LAP.

Role of Computed Tomography in Pre- and Postoperative Evaluation of a Double-Outlet Right Ventricle.

Double-outlet right ventricle (DORV) is a type of ventriculoarterial connection in which both great arteries arise entirely or predominantly from the right ventricle. The morphology of DORV is characterized by a ventricular septal defect (location and relationship with the semilunar valve); bilateral coni and aortomitral continuity; the presence or absence of outflow tract obstruction; tricuspid-pulmonary annular distance; and associated cardiac anomalies. The surgical approach varies with the type of DORV and is based on multiple variables. Computed tomography (CT) is a robust diagnostic tool for the preoperative and postoperative assessment of DORV. Unlike echocardiography and magnetic resonance imaging (MRI), CT imaging is not limited by small acoustic window, need for anaesthesia and can be used in patients with metallic implants. Current generations CT scanners with high spatial and temporal resolution, wide detectors, high-pitch scanning mode, dose-reduction algorithms, and advanced three-dimensional post-processing tools provide a low-risk, high-quality alternative to diagnostic cardiac catheterization or MRI, and have been increasingly utilized in nearly every type of congenital heart defect, including DORV.

Effect of conventional and rapid-deployment aortic valve replacement on the distance from the aortic annulus to coronary arteries.

This study aimed to compare the effect of surgical aortic valve replacement (SAVR) on coronary height in patients undergoing SAVR with rapid-deployment or SAVR with several standard sutured bioprostheses. This study may identify patients at higher risk of coronary obstruction during valve-in-valve procedures. We analysed 112 patients [mean age 71 (9 SD) years] who underwent SAVR with either a rapid-deployment aortic bioprosthesis (EDWARDS INTUITY Elite Valve) or other standard sutured biological valves. The coronary heights were assessed by computed tomography scan with the Philips 3D HeartNavigator system. Two groups of patients were analysed: 51 (45.5%) patients implanted with an RD-AVR, which is a supra-annular valve that requires 3 anchoring sutures without the use of pledgets, and 61 (54.5%) patients implanted with a conventional supra-annular sutured bioprosthesis. The mean right and left coronary artery-to-annulus (RCAA and LCAA) heights at baseline were 16.9 (4.6 SD) and 14.2 (4.0 SD) mm in the standard sutured group and 16.3 (3.5 SD) and 12.8 (2.9 SD) mm in the RD-AVR group, respectively; a significantly shorter distance was observed for the left coronary artery in the rapid-deployment group (P = 0.420 for RCAA height and P = 0.044 for LCAA). Postoperatively, the mean RCAA and LCAA heights were significantly decreased in both groups compared to baseline. A mean of 11.5 (4.8 SD) mm for the RCAA and 7.9 (4.3 SD) mm for the LCAA in the standard sutured group as well as 14.4 (3.9 SD) mm for the RCAA and 9.0 (3.1 SD) mm for the LCAA in the RD-AVR group were observed (P < 0.001 for RCAA and LCAA in both the sutured and rapid-deployment groups). Despite the significant difference in the mean distance from the left coronary artery to annulus between the groups at baseline, the postoperative mean distance of the LCAA to the sewing ring was still higher in the RD-AVR group. A significantly shorter coronary artery-to-aortic annulus distance for both the right and left main coronary arteries was observed after AVR with different conventional sutured supra-annular bioprostheses compared to AVR with rapid-deployment valves. These findings might be relevant for bioprosthesis selection, especially for young patients.

Mitral valve annulus and circumflex artery: Invivo study of anatomical zones.

ObjectiveTo provide, with the use of preoperative coronary computed tomography angiography, an in vivo anatomical characterization of the relationship between the circumflex artery and mitral valve annulus to identify different risk classes and to increase the surgical awareness of those anatomical relations.MethodsNinety-five (mean age: 64.2 ± 11.7) consecutive patients, initially referred for elective minimally invasive mitral valve surgery, underwent preoperative coronary computed tomography angiography. The distance between the circumflex artery and mitral annulus was assessed using 6 points designed on the posterior mitral annulus, starting from the anterolateral to the posteromedial commissure; this design created an ideal 5-zone system. High-risk anatomy was defined as a distance less than 3 mm between the circumflex artery and the mitral valve annulus.ResultsThe shortest distance between the circumflex artery and mitral valve annulus was observed at the area between the anterolateral commissure and the midpoint of P1 scallop, so-called zone 1 (5.49 ± 3.13 mm), whereas the longest distance occurred at zone 5 (12.03 ± 4.93). Twenty-four patients (25%) were identified with high-risk anatomy (mean distance 1.94 ± 0.8 mm). Left dominant and co-dominant hearts demonstrated a shorter circumflex artery–mitral valve annulus distance at all the zones. At multinomial logistic regression, the pattern of coronary dominance and the size of the circumflex artery were independent factors for high-risk anatomy.ConclusionsCoronary computed tomography angiography is a useful investigation to identify patients at risk of circumflex artery flow disturbance; for high-risk anatomy, this knowledge may enhance a safer operative technique.

CT‐Angiography to predict outcome after indirect mitral annuloplasty in patients with functional mitral regurgitation

Coronary sinus (CS) based mitral annuloplasty using the Carillon device is effective in reducing functional mitral valve regurgitation (FMR). However, this positive effect might be dependent on the relation between CS and the mitral annulus. Computed tomography (CT) assessment prior to mitral valve interventions is an emerging technique to optimize patient selection. In a retrospective analysis 30 patients underwent Carillon device implantation and received CT-angiography prior to CS based percutaneous mitral valve repair. Patients were assigned to responders or non-responders according to the 3-month transthoracic echocardiographic follow-up including quantitative mitral valve regurgitation assessment. A prototype software for CS reconstruction was used to assess distance and angle of both CS and mitral annulus planes. Comparison of the distance and angle of the CS plane and the mitral valve annulus plane showed a significant shorter distance and lower angle in the responder group implicating an impact on procedure success. Our results suggest a CS plane and MV annulus plane with a favorably distance of <7.8 mm and an optimal angle of <14.2° could be considered favorably for mitral annuloplasty using a Carillon device. Distance and angle of mitral annulus and CS planes determined by three-dimensional reconstructions of CT-angiography might predict a reduction in echocardiographic FMR using Carillon Mitral Contour System.

Effect of renin-angiotensin system inhibition on cardiac structure and function and exercise capacity in heart failure with preserved ejection fraction: a meta-analysis of randomized controlled trials.

Targeting the renin-angiotensin system (RAS) pathways has been considered a logical intervention for patients with heart failure with preserved ejection fraction (HFpEF), due to its hypothesized link to left ventricular (LV) remodeling. Although the effects of RAS inhibitors including angiotensin-converting enzyme inhibitors (ACE-Is), angiotensin receptor blockers (ARBs), and direct renin inhibitors (DRIs) on LV structure and function and exercise capacity in HFpEF patients have been examined in multiple randomized controlled trials (RCTs), results are inconsistent due partly to limited power. We conducted a meta-analysis of RCTs on the effects of RAS inhibitors on LV structure and function as well as exercise capacity in HFpEF patients. The search of electronic databases identified 7 trials including 569 patients; 4 trials were on ACE-Is; 2 on ARBs; and 1 on DRIs. Follow-up duration ranged across trials from 12 to 52weeks. The pooled analysis showed that RAS inhibitors significantly increased EF compared with control (weighted mean difference [95% CI] = 2.182 [0.462, 3.901] %). In contrast, RAS inhibitors did not significantly change the ratio of peak early to late diastolic mitral inflow velocities (weighted mean difference [95% CI] = 0.046 [- 0.012, 0.105]), early diastolic mitral annular velocity (0.327 [- 0.07, 0.725] cm/s), the ratio of early diastolic mitral inflow to annular velocities (0.291 [- 0.937, 1.518]), LV mass (- 6.254 [- 15.165, 2.656] g), or 6-min walk distance (1.972 [- 14.22, 18.163] m) compared with control. The present meta-analysis suggests that RAS inhibitors may increase LVEF in HFpEF patients.

Epidemiological, clinical, and echocardiographic features, and outcome of dogs with Ebstein's anomaly: 32 cases (2002–2016)

Ebstein's anomaly (EA) is a congenital heart disease characterized by apical displacement of the tricuspid valve leaflets in the right ventricle. The objective of this retrospective study was to investigate the signalment, clinical features, echocardiographic findings, and outcome of dogs with EA. Medical records of 40 dogs with EA were reviewed. Echocardiographic variables used to assess EA severity in human pediatrics were also evaluated (e.g. displacement index, Celermajer index, Carpentier class, and apex-mitral annulus:apex-tricuspid annulus distance ratio). Labrador retriever was the most commonly recruited breed (24 of the 40 dogs, 60%). Eight of the 40 dogs with EA had hemodynamically compromising concurrent heart (n=7) or respiratory diseases (n=1). A right apical systolic heart murmur (median grade=5/6) was detected in the remaining 32 dogs, without any other clinical sign related to EA in 19 of the 32 dogs (59%). Median (interquartile range) values of the displacement index and Celermajer index were 17.4mm/m2 (12.0-21.9) and 100% (50-130), respectively. Median time to all-cause death was 74 months, and 72% dogs (95% confidence interval, 50-86%) had not succumbed to cardiac death (CD) 160 months after diagnosis. Univariate analyses showed that the time from diagnosis to CD was associated with the presence of clinical signs, ascites, severe right atrial dilation, palpable thrill, and a Celermajer index ≥100%. Right atrial enlargement is significantly associated with decreased survival time of dogs with EA although most may live for years and may not die from CD. These results support medium to long-term survival for most dogs with EA.

Epicardial Posterior Papillary Muscle Repositioning with Mitral Annular Reduction for FIMR Treatment: Initial Ex Vivo Heart Model Study.

High recurrent functional ischemic mitral regurgitation (FIMR) has been observed after annuloplasty. Since annuloplasty alone could not prevent late recurrent FIMR or improve the survival rate after CABG, adjunctive subvalvular opt for better treatment tailored for each individual patient. Ex vivo ovine heart models with annular dilatation and PPM displacement were used for analysis of mitral regurgitation (MR) flow, left ventricular and annular geometry after treatment by mitral annular reduction alone (MA, nMA = 12) or combined with epicardial PPM repositioning (MA+PPM, nMA+PPM=13). MR significantly was reduced from baseline in both the MA (P = .03) and MA+PPM (P = .02) groups, but was not significantly different between the groups. The septo-lateral mitral annular distance decreased after applying both methods (MA group P = .005; MA+PPM group P = .05). The tethering α angle of the APM in the frontal plane significantly increased from baseline in the MA+PPM group (P = .027). Furthermore, the MA+PPM group had a larger APM and PPM α angle in the frontal plane compared with the MA group after reducing the MR (P = .04). There were no statistically significant changes in tethering angles found in the MA group compared with baseline. MR reduction correlated with percentage decrease of septo-lateral mitral annular distance (rs = 0.51, P = .01), the percentage decrease of fibrosa-PPM distance (rs = 0.43, P = .03), and the percentage increase of the PPM anterior displacement (rs = -0.41, P = .04). The decreased tethered angle of the PPM referred to the annulus, and the decreased interpapillary muscles distance suggested the PPM was repositioned inward and toward the septal annulus by the epicardial pushing pad. Epicardial repositioning of the PPM adjunct with mitral annular reduction facilitated leaflet coaptation without the risk of overlying restriction of the mitral annular orifice.

41 Geometric change in valvular apparatus during tricuspid repair for severe tricuspid regurgitation

Abstract Background For repairing severe tricuspid regurgitation (TR) with leaflet tethering, our team employs spiral suspension procedure, in which papillary muscles (PMs) are approximated and suspended towards annulus by suture in addition to annuloplasty. Purpose To visualize subtricuspid apparatus and investigate its geometric change by the procedure, comparing with annuloplasty alone. Methods 11 patients who underwent spiral suspension and 10 patients who underwent annuloplasty alone were studied. Using 3D dataset derived from transesophgeal echocardiography with transgastric approach, the distances between the mid septal annulus (point C) and the anterior PM tip (point A) and posterior PM (point P) were calculated. Also, annular perimeter, leaflet surface area and tenting height were measured Results In all cases, PM tips could be visualized and identified for the measurements. By spiral suspension, the distance CA and tenting height were significantly reduced. On the other hand, by annuloplasty alone, CA and tenting height were likely to be increased but statistically not significant. Conclusions Spiral suspension ameliorated leaflet tethering with relocating PMs. Annuloplasty alone reduced leaflet surface area, which indicates increase of coaptation surface. Interestingly, PM tip- annulus distance and tenting height were possibly increased by annuloplasty. Further investigation is need in large number. Result of measurements Annuloplasty alone Spiral suspension Pre-op Post-op Pre-op Post-op Annular perimeter, mm 120.9 ± 11.2 78.8 ± 5.1* 142.4 ± 18.2* 81.1 ± 6.4** Leaflet surface area, cm2 13.1 ± 3.1 5.6 ± 0.9* 19.3 ± 4.8* 5.8 ± 0.8** Tenting height, mm 2.8 ± 2.3 3.1 ± 1.2 7.0 ± 4.8* 2.9 ± 2.6** CA, mm 27.3 ± 3.9 29.1 ± 6.2 35.7 ± 6.9* 29.6 ± 5.2** CP, mm 33.1 ± 6.0 33.8 ± 9.4 38.5 ± 8.2 33.9 ± 6.1 *p &amp;lt; 0.05, vs Annuloplasty alone pre-op **p &amp;lt; 0.05, vs Spiral suspension pre-op Abstract 41 Figure. Pre- and post-operative valve apparatus

P3695Predicting adverse outcomes after TAVI procedure - a comparison of two CoreValve generations using real-life outcomes and patient-specific computer simulations

Abstract Background and aim Post-procedure conduction abnormalities (CA) and paravalvular aortic regurgitation (PAR) continue to strain TAVI outcomes. Computer simulations, based on patient-specific anatomy, valve properties, and implantation position, have been validated for prediction of these complications. The new-generation CoreValve Evolut PRO has been shown to have lower levels of PAR and CA than previous generations. The aim was to compare clinical outcomes after Evolut Pro implantation in real-life with outcomes of virtual deployment of the same size, implantation depth adjusted CoreValve Evolut R. Methods Patients undergoing Evolut Pro implantation at a single centre were included into the study. Postoperative Doppler echocardiography was assessed to define PAR, the pre- and postoperative 12-lead ECGs for CA, and the postoperative angiograms to measure implantation depth based on annular plane distance from the non-coronary and left coronary aortic valve cusps. Preoperative multislice computed tomography was used to generate patient-specific models of the native aortic root. Implantation of the Evolut R valve and corresponding aortic root deformation was simulated using computational mechanics, whereas blood flow and level of PAR were predicted using computational fluid dynamics. Prediction of CA – new onset left bundle branch block or atrioventricular block type II or III -was based on calculations of contact pressure in a patient-specific region of the aortic root containing the AV conduction system (ROI). Outcomes were predicted in three implantation depth positions - high, medium, low – where the position closest to the real-life implantation depth was chosen for outcome comparisons. Results Study diagram is shown in Figure 1. Thirty-three patients (57% female, mean age 82±6 years old) underwent a TAVI intervention with an Evolut PRO valve. Evolut PRO implantation depths were, in general, closest to the lowest modeled Evolut R depth. Comparison demonstrated similar overall incidence of moderate-to-severe PAR. The Evolut R simulation predicted 18 patients without PAR and 2 with PAR. With the Evolute PRO, 1 of the 18 not predicted developed significant PAR, and 1 of the 2 predicted did not develop PAR. CA were notably higher with the Evolut R simulation, where CA were present in 9 out of 12 patients, as compared to the observed 5 out of 12 with the Evolut PRO. Figure 1 Conclusion Single-centre outcomes after Evolut Pro implantation in real-life showed a similar overall incidence of moderate-to-severe PAR and a lower incidence of conduction abnormalities as compared to the same size, implantation depth adjusted, patient-specific Evolut R modeled outcomes. As inferred from the results, computer simulations may have high clinical utility in supporting clinical decisions regarding valve choice in TAVI procedures. Acknowledgement/Funding Horizon 2020 European Commission Project H2020-MSCA-ITN-2016 (764738)

The Impact of a New "Inverted Arch" Prosthetic Annuloplasty Ring on the Mitral Valve's 3-D Motion: An Experimental Ex-Vivo Study.

This experimental study aimed to evaluate the ex-vivo three-dimensional (3-D) motion of the Inverted Arch Ring (IAR), an innovative new design concept for a flexible incomplete annuloplasty prosthesis with an incorporated stabilizing rigid arch that can be used in correcting mitral valve regurgitation. Twenty explanted porcine hearts were placed in a circulation simulation system. Ultrasonometry transducers implanted in the mitral annulus were used to measure the 3-D valvular motion during a simulated cardiac cycle. Annular distance measurements were recorded and compared in each heart before and after the implantation of the IAR prosthesis at pressures corresponding to mid-systole and mid-diastole. Distances measured in mid-systole and mid-diastole demonstrated no significant differences in annular motion or in valve areas either prior to or after IAR implantation. Therefore, the results of this study confirm the minimal effects exerted by the IAR prosthesis on the mitral valve’s 3-D motion during a simulated cardiac cycle.

Modelling of thermal effects in a slim tin fixed-point cell

Slim fixed-point cells are an economic and suitable alternative for calibration of industrial platinum resistance thermometers, which are widely used in research and industrial applications. The most relevant disadvantage of slim cells is related with thermal effects produced by interactions between the cell and the furnace used for the realization of the fixed-points. This work presents the implementation of a two-dimensional numerical model that considers the transient heat transfer due to conduction, radiation and latent heat. The main goal was to evaluate different geometrical parameters in the design of slim fixed-point cells. Results show that thermal effects are mitigated when the annular distance between interior and exterior walls of the crucible is maximum, while the length of the cell and the thermo-well must be setup according to the temperature gradients in the furnace to avoid undesirable heat fluxes.

Modified Tricuspid Annular Plane Systolic Excursion for Assessment of Right Ventricular Systolic Function.

BACKGROUNDTricuspid annular plane systolic excursion (TAPSE) has become a popular tool for assessing right ventricular (RV) systolic function because of its ease of application. TAPSE using transesophageal echocardiography (TEE) is limited by alignment with the lateral wall of the RV. Modified TAPSE (m-TAPSE) is a novel method for measuring TAPSE. m-TAPSE is the difference in the ‘apical to lateral tricuspid annulus distance’ during diastole and systole. The aim of the present study was to compare prospectively m-TAPSE with the most commonly used parameter TAPSE and near-gold standard 2D echocardiographic parameter RV fractional area change (RV FAC).METHODSWe conducted a prospective observational study of 125 consecutive patients undergoing coronary artery bypass graft surgery in a single tertiary care center. Post-anesthetic induction TAPSE was recorded using transthoracic echocardiography (TTE). m-TAPSE was recorded using TEE in the mid-esophageal four-chamber view. RV FAC was also assessed using TEE. m-TAPSE < 16 mm, TAPSE < 16 mm and RV FAC < 35% were taken as cut-offs for RV systolic dysfunction. Correlations were assessed using the Pearson correlation coefficient. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated using 2 × 2 cross table.RESULTSm-TAPSE was significantly correlated with TAPSE (r = 0.797, p < 0.001). Similarly, a significant correlation was observed between m-TAPSE and RV FAC (r = 0.602, p < 0.001). The sensitivity, specificity, PPV, NPV, and accuracy of m-TAPSE were 100%, 98.3%, 80%, 100% and 98.4%, respectively.CONCLUSIONSm-TAPSE correlated well with both RV FAC and TAPSE. Therefore, m-TAPSE can be considered an easily measurable alternative parameter for evaluating RV systolic function in a busy intraoperative setting.

Abstract 16731: Novel CMR Anatomical Predictors of Mitral Regurgitation Presence and Severity in Mitral Valve Prolapse

Introduction: Mitral valve (MV) prolapse (MVP) is often associated with mitral regurgitation (MR). The determinants of MR in MVP are incompletely understood. Methods: We retrospectively identified 86 consecutive patients with MVP and preserved ejection fraction undergoing CMR with velocity encoding for MR quantification between 2005 and 2017. On 3-chamber cine images we measured, in end-diastole (Figure), end-systole, and their percentage change during the cardiac cycle, the following parameters: basal and mid inferolateral wall thickness, posterior papillary muscle length, annulus diameter, LV diameter and distance from the posterior papillary muscle to anterior and posterior annulus. In addition, we measured anterior and posterior leaflet thickness in diastole and maximal prolapse distance in end-systole. We explored the associations between these parameters and mitral regurgitant fraction (RF) using multivariate linear regression. Results: Median age was 52.6 years and 48% were males. There was posterior MVP in 49 (57%), bileaflet MVP in 35 (41%) patients, and isolated anterior MVP in 2 (2%) patients. MR was present in 73 (85%) and, in these, median RF was 23% (IQR 13-33%). In multivariate analyses, diastolic papillary muscle to posterior annulus distance, maximal prolapse distance, maximal posterior leaflet thickness, and LV basal inferolateral diastolic thickness were independent predictors of mitral RF (p&lt;0.05 for all). Conclusions: Beyond known determinants of MR in MVP such as maximal prolapse and leaflet thickness, we identified novel anatomical predictors of MR severity, namely increased diastolic papillary muscle to posterior annulus distance and LV basal inferolateral thickness. Whether these abnormalities represent secondary changes to MVP (i.e. basal inferolateral “stretch” and compensatory regional LV hypertrophy, respectively) or primary phenotypic features of the MVP syndrome is uncertain.