Left Ventricular Outflow Tract Dimensions Research Articles

Assess the Outcomes of Transcatheter Aortic Valve Replacement in Bicuspid Valve with Mixed Disease versus Predominant Aortic Stenosis.

In mixed aortic valve disease (MAVD), the results of transcatheter aortic valve replacement (TAVR) are conflicting. There is limited data on the outcomes of TAVR in patients with bicuspid aortic valve (BAV) and MAVD. The objective of this study is to compare outcomes after TAVR in BAV patients with MAVD and predominant aortic stenosis (PAS). Patients with BAV who underwent TAVR between January 2016 and April 2023 were included. The primary outcome was device success. The secondary endpoints were periprocedural mortality and other complications as defined by the Valve Academic Research Consortium-3 (VARC-3). Propensity score matching was used to minimize potential confounding. A total of 262 patients were included in this study, 83 of whom had MAVD. The median age was 72 years, and 55.7% were male. The baseline comorbidity risk files were comparable between the two groups. Patients with MAVD had more mitral regurgitation, tricuspid regurgitation and pulmonary hypertension, larger annular and left ventricular outflow tract dimensions, and more severe calcification than PAS. In the unmatched population, MAVD patients had similar device success rate (69.9% vs 79.9%, P=0.075) and 30-day mortality (3.6% vs 3.4%, P=1) compared to PAS. Propensity score matching resulted in 66 patient pairs. Device success rate were still comparable in the matched population. Other clinical outcomes, including stroke, bleeding (type 2-4), major vascular complications, acute kidney injury (stage 2-4) and permanent pacemaker implantation, were comparable between the two groups. Multivariable logistic regression analysis did not show MAVD to be an independent negative predictor of device success. At one year, survival was similar between patients with MAVD and those with PAS. For the bicuspid valve, patients with MAVD had a more challenging anatomy. MAVD patients associated with comparable 30-day clinical outcomes after TAVR compared to PAS patients in patients with BAV.

Sex-specific echocardiographic phenotypes in left ventricular outflow tract obstruction

Abstract Funding Acknowledgements Type of funding sources: None. Background Previous studies have reported major sex differences in prevalence, demographics, and timing of intervention in left ventricular outflow tract (LVOT) obstruction. Whether the observed differences are related to LVOT anatomy is less explored. Purpose The aim of this study was to assess the anatomic substrate for LVOT obstruction by echocardiography to identify sex-specific phenotypes. Methods We included 76 patients (37% women) with symptomatic LVOT obstruction referred to a tertiary care centre between 2005-2020 to be considered for septal ablation or myectomy. A standardized echocardiography was extended with systematic measurements of parasternal LVOT dimensions at 5, 10 and 15 mm below the aortic valve, proximal septal thickness at 10, 20 and 30 mm, subaortic septal bulge radius and aortoseptal angle in all patients prior to intervention (Image). Measurements were also adjusted for body surface area (BSA). A total of 3 patients had to be excluded from analysis due to poor image quality. Results Women were older (p < 0.001, Table), while there were no differences in body mass index (27.6 v.s. 27.5, p = ns), systolic and diastolic blood pressure (133 v.s 133 mmHg, p = ns and 75 v.s 80 mmHg, p = ns, respectively), or prevalence of hypertension (24% v.s. 29%, p = n.s). Left ventricular end-diastolic diameter, LVOT diameters and septum thickness measured 30 mm from the aortic valve were lower in women (Table). However, in all these measurements the differences disappeared after adjusting for BSA. There were no sex differences in posterior wall thickness. Furthermore, the aortoseptal angle was steeper among women, and the septum bulge radius smaller, remaining so even after adjustment for BSA(Table). Conclusion In women with LVOT obstruction, the septum bulge radius adjusted for BSA was smaller, and the aortoseptal angle steeper. Our findings suggest that there may be important sex differences in the echocardiographic phenotype in LVOT obstruction. Abstract Table Abstract Figure. Image

Acute Cardiac Alterations Among Young Adults With Sars-CoV-2

BACKGROUND The novel SARS-CoV-2 virus inflicts far-reaching health decrements, both directly and through secondary inflammatory stimulation. To date, there is little information regarding the effects of COVID-19 on the heart after infection, especially among young healthy adults. PURPOSE: We sought to determine whether contracting SARS-CoV-2 affects cardiac function in young, otherwise healthy adults, weeks after testing positive for SARS-CoV-2. METHODS: Transthoracic echocardiography was performed on 14 subjects with SARS-CoV-2 (8F/6M, 21 ± 1y, 24 ± 3 kg·m-1) who tested positive 3-4 weeks prior to study test date. A parasternal long-axis view was utilized to measure septal and left ventricular posterior wall thickness, left ventricular volume, and left ventricular outflow tract dimensions. A four-chamber view was utilized to measure mitral valve function, diastolic function, end diastolic and systolic volume, and ejection fraction. Z-tests were performed to determine if these values were significantly different from sex- and age-matched normative values with significance set at p < 0.01 (mean ± SD). RESULTS: The left ventricular diastolic mass and index were found to be higher in both female (Mass: 173 ± 52 g, Index: 95 ± 18 g/m^2) and male (Mass: 214 ± 34 g, Index: 110 ± 15 g/m^2) subjects with SARS-CoV-2 compared to reference values (Female Mass: 104 ± 28 g, Female Index: 62 ± 15 g/m^2, Male Mass: 143 ± 39 g, Male Index: 72 ± 18 g/m^2) (p < 0.01). Septal wall e’ was elevated in both female (0.16 ± 0.05 m/s) and male (0.15 ± 0.01 m/s) subjects compared to reference values (Female: 0.12 ± 0.2 m/s, Male: 0.12 ± 0.03 m/s) (p < 0.01). CONCLUSIONS: The current findings suggest subclinical alterations to the myocardium of young adults who have recently contracted SARS-CoV-2. These results warrant further review to examine whether low-level myocardial inflammation or interstitial edema may be present and whether persistent systemic vascular resistance may be causing left ventricular dysfunction and wall thickening.

Longitudinal Tracking of Cardiac Alterations Among Young Adults with SARS‐CoV‐2

BackgroundThe novel SARS‐CoV‐2 virus inflicts far‐reaching health decrements, both directly and through secondary inflammatory stimulation. To date, there is little information regarding the effects of COVID‐19 on the heart after infection, especially among young healthy adults.PurposeWe sought to determine whether contracting SARS‐CoV‐2 affects cardiac function in young, otherwise healthy adults and whether these alterations recede after testing positive for SARS‐CoV‐2.MethodsTransthoracic echocardiography was performed on 7 subjects with SARS‐CoV‐2 (3F/4M, 21±1y, 24±2 kgᐧm‐1) who tested positive 3‐4 weeks prior to baseline testing followed by 1‐month and 2‐month follow‐up testing. A parasternal long‐axis view was utilized to measure septal and left ventricular posterior wall thickness, left ventricular volume, and left ventricular outflow tract dimensions. A four‐chamber view was utilized to measure mitral and tricuspid valve, left ventricular, and pulmonary vein function. Data are mean±SD.ResultsStroke volume (Baseline: 44±11ml, 1‐month: 42±13ml, 2‐month: 54±12ml) and stroke index (Baseline: 24±6ml/m^2, 1‐month: 22±7ml/m^2, 2‐month: 29±6ml/m^2) were elevated at 2‐month follow‐up (p<0.05). Left ventricular posterior wall thickness was lower at 1‐month follow‐up (Baseline: 1.56±0.10cm, 1‐month: 1.44±0.08cm, 2‐month: 1.47±0.13cm) (p<0.05). Pulmonary vein systolic flow decreased at 2‐month follow‐up (Baseline: 0.64±0.04m/s, 1‐month: 0.58±0.07m/s, 2‐month: 0.49±0.08m/s) (p<0.05).ConclusionsThe current findings suggest subclinical alterations to the myocardium of young adults who have recently contracted SARS‐CoV‐2. Further, these results may be reflective of a myocardium which is recovering months following initial infection.

One Hundred Percent Reparability of Mitral Prolapse: Results of a Dynamic Nonresectional Technique

BackgroundWe studied the results of a dynamic mitral repair technique that preserves normal mitral valve function by avoiding leaflet resection and rigid and semirigid annuloplasty rings. MethodsIn previous reports we demonstrated that intraoperative simulation of mitral valve locking and isovolumic systole by rapid left ventricular inflation with pressurized saline accurately simulates mitral annular and leaflet shape and position, and left ventricular outflow tract dimensions. Length of polytetrafluoroethylene neochordae and size of fully flexible adjustable annuloplasty ring can be adjusted in three dimensions for accurate apposition of zones of leaflet coaptation, premarked with dots. We followed 1068 consecutive patients after repairs performed between 2001 and 2018. ResultsOf the 1068 patients, 674 were men (63.1%). Mean age was 62.25 ± 13 years. Leaflet repaired was anterior in 118 patients (11.05%), posterior in 564 (52.81%), both in 55 (5.15%), and neither in 123 (11.5%). Barlow's disease was present in 208 patients (19.48%). Repair was isolated in 82.5% (881 of 1068). Reparability was 100%. Perioperative mortality overall was 1.59% (17 of 1068): isolated repair, 1.14% (10 of 881); and isolated posterior leaflet, 0.85% (4 of 472). Leaflet systolic anterior motion occurred in 1.7% (18 of 1068), and was significant in 0.4% (4 of 1068). Survival at 10 years by Kaplan-Meier analysis was 74.65%, freedom from reoperation was 96.01%, and freedom from severe mitral regurgitation was 94%. The only predictor of reoperation (Cox analysis) was being male (P = .001). ConclusionsUse of intraoperative simulation of mitral dynamics led to 100% reparability for degenerative valves with minimal systolic anterior motion, despite no leaflet resection. Long-term durability has been good and similar for all leaflets.

Outcomes After Left Ventricular Outflow Tract Reconstruction With a Tube Graft for Annular Erosion

Aortic annular erosion is a serious complication of aortic valve endocarditis or previous aortic valve replacement. This study examined the outcomes of a technique for left ventricular outflow tract reconstruction using a polyester tube graft, followed by translocation of the aortic valve and coronary arteries. A total of 23 patients with extensive annular erosion resulting from endocarditis or previous aortic valve replacement with or without pseudoaneurysm formation, or occurring after excision of the native valve, underwent suture of a polyester tube graft in the left ventricular outflow tract below the annulus, replacement of the aortic valve and proximal ascending aorta with a composite graft, and reimplantation of the coronary arteries with the use of interposition polyester grafts. The mean age of the patients was 50 years, and 57% were men. There were no hospital deaths. The mean duration of follow-up was 6.5 years and extended to 16 years. Actuarial survival at 1, 5, and 10 years was 86.7%, 82.2%, and 62.6%, respectively. Two patients required reoperation for a graft-graft pseudoaneurysm and for degeneration of a porcine bioprosthesis. Echocardiograms obtained at a mean of 75 months postoperatively in 15 of the 23 patients demonstrated normal left ventricular outflow tract dimensions and velocities and a mean effective valve orifice area of 1.07 cm2/m2. All coronary artery grafts were patent on angiography a mean of 40 months postoperatively in 13 patients. Extended experience with this technique confirms its safety and effectiveness for patients withextensive destruction of the aortic annulus. It represents a suitable alternative to other currently used techniques.

The relation of left ventricular geometry to left ventricular outflow tract shape and stroke volume index calculations.

Stroke volume (SV) and aortic valve area calculations require the left ventricular (LV) outflow tract (LVOT) or aortic annular area calculations that involve squaring the respective diameters. Area calculation errors became evident with transcatheter aortic valve replacement where areas were underestimated due to an elliptical annulus. We hypothesized that LVOT and annular shape are more elliptical in patients with greater relative LV wall thickness (RWT) leading to underestimation of SV index using 2D Doppler echocardiography. We studied 203 consecutive patients referred to an outpatient noninvasive laboratory for Doppler echocardiograms which included acceptable 3-dimensional images. 3-dimensional assessment of the LVOT at 3-5mm from the valve insertion, at the site of valve insertion, and at the sinus of Valsalva (SOV) was performed with assessment of the minor axis (MN), major axis (MJ), and areas at mid-systole. SV index was calculated from LVOT and annular diameters obtained from 2-dimensional echo and from 3-dimensional LVOT areas. An inverse relation of RWT with MN/MJ at mid-systole for the LVOT (r=0.5812, P<0.0001) and annulus (r=0.6865, P<0.0001) was noted. LVOT and annulus areas were similar among groups at mid-systole. SV index calculated from 2D LVOT dimensions was significantly smaller than using 3D LVOT areas (35.6±8.9 vs 53.6±16.1mL, P<0.0001). There is an inverse relation between MN/MJ and RWT at the LVOT and aortic annulus despite the LVOT and annular areas being similar across most geometries resulting in SV index underestimation calculated using LVOT diameters vs 3D LVOT areas.

Three-Dimensional Morphology of the Left Ventricular Outflow Tract: Impact on Grading Aortic Stenosis Severity

Left ventricular outflow tract (LVOT) measurement is a critical step in the quantification of aortic valve area. The assumption of a circular morphology of the LVOT may induce some errors. The aim of this study was to assess the three-dimensional (3D) morphology of the LVOT and its impact on grading aortic stenosis severity. Fifty-eight patients with aortic stenosis were studied retrospectively. LVOT dimensions were measured using 3D transesophageal echocardiography at three levels: at the hinge points (HP) of the aortic valve and at 4 and 8mm proximal to the annular plane. Results were compared with standard two-dimensional echocardiographic measurements. Three-dimensional transesophageal echocardiography showed a funnel shape that was more circular at the HP and more elliptical at 4 and 8mm proximal to the annular plane (circularity index=0.92 vs 0.83 vs 0.76, P<.001). Cross-sectional area was smaller at the HP and larger at 4 and 8mm from the annular plane (3.6 vs 3.9 vs 4.1cm2, P=.001). The best correlation between two-dimensional and 3D transesophageal echocardiographic dimensions was at the HP (intraclass correlation coefficient=0.75; 95% CI, 0.59-0.86). When the HP approach was selected, there was a reduction in the percentage of patients with low flow (from 41% to 29%). A large portion of patients with aortic stenosis have funnel-shaped and elliptical LVOTs, a morphology that is more pronounced in the region farther from the annular plane. Two-dimensional LVOT measurement closer to the annular plane has the best correlation with 3D measurements. Measurement of the LVOT closer to the annular plane should be encouraged to reduce measurement errors.

Importance of the left ventricular outflow tract in the need for pacemaker implantation after transcatheter aortic valve replacement

BackgroundThe interaction of left ventricular outflow tract (LVOT) and transcatheter heart valve (THV) is complex and may be device design specific. We sought to study LVOT characteristics and its relation with permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR). MethodsWe studied 302 patients with a median age of 81years [75–84]. Computed tomography was used to assess LVOT in terms of amount of calcium, perimeter and device size relative to LVOT. ResultsWe implanted a Medtronic CoreValve (MCS) in 203 patients, Edwards-Sapien XT (ESV-XT) in 38, Edwards-Sapien S3 (ESV-S3) in 26 and Lotus in 35 patients. Sixty-eight patients (22.5%) received a new PPI within 30days after the index procedure. The incidence of PPI was 22.7% with MCS, 10.5% with ESV-XT, 26.9% with ESV-S3 and 31.4% with Lotus. By multivariate analysis RBBB at baseline (OR 2.9 [1.2–6.9, p=0.014), second generation valves (OR 2.1 [1.0–4.5], p=0.048), DOI (OR 1.20 per 1mm increment, [1.09–1.31], p<0.001) and LVOT sizing (OR per 1% increment 1.03 [1.01–1.07], p=0.022) were associated with need for PPI. Sensitivity analyses suggest that a lesser degree of LVOT oversizing triggers PPI with second generation THVs vs. first generation THVs. ConclusionsMore LVOT oversizing is associated with a higher need for permanent pacemaker implantation after TAVR, even more so with deeper THV implants and next generation devices (ESV-S3 and Lotus). Sizing algorithms should focus more on LVOT dimensions to reduce PPI.

Abstract 17783: Improved Aortic Valve Area Calculation Using a Novel Biplane Echo Continuity Equation

The aim of this study was to improve the accuracy of transthoracic echo- cardiographic (TTE) assessment of the aortic valve area (AVA) in patients with aortic stenosis (AS). The traditional continuity equation (CE) for determining AVA requires a measurement of left ventricular outflow tract (LVOT) area, which is calculated from a linear LVOT dimension using the parasternal long axis view, assuming circular geometry. However, routine use of multidetector computed tomography (MDCT) in patients undergoing evaluation for transcatheter aortic valve replacement (TAVR) has shown that the LVOT is elliptical rather than round. Assumption of circular geometry may introduce inaccuracies into AVA assessment. A total of 61 patients (76 ± 11 years of age, 61% men) with isolated calcific AS (mean gradient 42 ± 9 mm Hg; ejection fraction 56 ± 11%) underwent Doppler TTE as part of pre TAVR or aortic valvuloplasty evaluation. AVA was calculated by TTE using two near- perpendicular planes (parasternal long axis and apical five chamber view) to evaluate the LVOT. A modified CE was used to calculate AVA (cm2) = (π((D1 x D2)/4)x LVOT VTI)/(AV VTI) in order to account for the elliptical rather than round shape of the LVOT. AVA measurements from the traditional and modified CE were compared to invasive AVA assessment. Biplane (Figure, Panel B+D) vs. traditional single plane (Panel A+C) TTE measurement of the LVOT yielded a significantly improved positive correlation between TTE and invasive AVA assessment (r2=0.861 vs. 0.296) and a markedly reduced mean error (0.07 cm2 vs. 0.18 cm2), p&lt;0.001. Utilizing the proposed modified continuity equation greatly improves the accuracy of TTE guided AVA measurements. This simple calculation can be performed using standard TTE without additional costly equipment (ie, biplane transducers), without additional echo views (ie, more sonographer time), and without the need to subject patients to further invasive or non- invasive testing (ie, TEE or MDCT).

Dietary ω-3 fatty acids protect against vasculopathy in a transgenic mouse model of sickle cell disease.

The anemia of sickle cell disease is associated with a severe inflammatory vasculopathy and endothelial dysfunction, which leads to painful and life-threatening clinical complications. Growing evidence supports the anti-inflammatory properties of ω-3 fatty acids in clinical models of endothelial dysfunction. Promising but limited studies show potential therapeutic effects of ω-3 fatty acid supplementation in sickle cell disease. Here, we treated humanized healthy and sickle cell mice for 6 weeks with ω-3 fatty acid diet (fish-oil diet). We found that a ω-3 fatty acid diet: (i) normalizes red cell membrane ω-6/ω-3 ratio; (ii) reduces neutrophil count; (iii) decreases endothelial activation by targeting endothelin-1 and (iv) improves left ventricular outflow tract dimensions. In a hypoxia-reoxygenation model of acute vaso-occlusive crisis, a ω-3 fatty acid diet reduced systemic and local inflammation and protected against sickle cell-related end-organ injury. Using isolated aortas from sickle cell mice exposed to hypoxia-reoxygenation, we demonstrated a direct impact of a ω-3 fatty acid diet on vascular activation, inflammation, and anti-oxidant systems. Our data provide the rationale for ω-3 dietary supplementation as a therapeutic intervention to reduce vascular dysfunction in sickle cell disease.

Invited Commentary

The report of David and colleagues [1David T.E. David C.M. Manlhiot C. Simplici-T Annuloplasty Band for mitral valve repair for degenerative disease.Ann Thorac Surg. 2014; 98: 1551-1556Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar] using an unmeasured, experience-based approach for mitral annuloplasty is similar to that of Brown and colleagues [2Brown M.L. Schaff H.V. Li Z. Suri R.M. Daly R.C. Orsulak T.A. Results of mitral valve annuloplasty with a standard-sized posterior band: is measuring important?.J Thorac Cardiovasc Surg. 2009; 138: 886-891Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar]. Bothe and colleagues [3Bothe W. Miller C. Doenst T. Sizing for mitral annuloplasty: where does science stop and voodoo begin?.Ann Thorac Surg. 2013; 95: 1475-1483Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar] recently provided an insightful summary of the need for detailed studies of the effects of the various mitral annuloplasty techniques. We also believe that the issues involved are complex and require rigorous investigation using clinical, echo, 2D, 3D, cMRI, cardiac CTA, finite stress analysis, and other engineering data to appreciate fully the effects of different repairs. Our own focus during repair is restoration of the relationships of all the elements whose interrelated structures and dynamic behavior are necessary for normal mitral valve function, starting with normal mitral diastolic locking [4Lawrie G.M. Structure, function, and dynamics of the mitral annulus: importance in mitral valve repair for myxomatous mitral valve disease.Methodist Debakey Cardiovasc J. 2010; 6: 8-14PubMed Google Scholar, 5David D. Michelson E.L. Naito M. Chen C.C. Schaffenburg M. Dreifus L.S. Diastolic locking of the mitral valve: importance of atrial systole and intraventricular volume.Circulation. 1983; 67: 640-645Crossref PubMed Scopus (36) Google Scholar, 6Decloedt A. Verheyen T. Sys S. De Clercq D. Bijnens B. Loon G.V. Influence of atrioventricular interaction on mitral valve closure and left ventricular isovolumic contraction measured by tissue Doppler imaging.Circ Cardiovasc Imaging. 2013; 6: 109-116Crossref PubMed Scopus (12) Google Scholar]. We have reported 100% reparability [7Lawrie G.M. Earle E.A. Earle N.R. Intermediate-term results of a nonresectional dynamic repair technique in 662 patients with mitral valve prolapse and mitral regurgitation.J Thorac Cardiovasc Surg. 2011; 141: 368-376Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar], superior durability of the annulus attachment [7Lawrie G.M. Earle E.A. Earle N.R. Intermediate-term results of a nonresectional dynamic repair technique in 662 patients with mitral valve prolapse and mitral regurgitation.J Thorac Cardiovasc Surg. 2011; 141: 368-376Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar, 8Spratt J.R. Spratt J.A. Beachley V. Kang Q. Strength comparison of mitral annuloplasty ring and suturing combinations: an in-vitro study.J Heart Valve Disease. 2012; 21: 286-292PubMed Google Scholar], and restoration of near normal annular dynamics [9Little S.H. Ben Zekry S. Lawrie G.M. Zoghbi W.A. Dynamic annular geometry and function in patients with mitral regurgitation: insights from three dimensional annular tracking.J Am Soc Echocardiogr. 2010; 23: 872-879Abstract Full Text Full Text PDF PubMed Scopus (42) Google Scholar, 10Ben Zekry S. Lang R. Sugeng L. et al.Mitral annulus dynamics early after valve repair: Preliminary observations of the effect of resectional versus non-resectional approaches.J Am Soc Echocardiogr. 2011; 24: 1233-1242Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar]. Left ventricular outflow tract dimensions and aortic-mitral angle by cMRI are unchanged postoperatively. Strain analysis showed normal strain distribution in all cases [11Ben Zekry S. Lawrie G. Little S. et al.Comparative evaluation of mitral valve strain by deformation tracking in 3-D echocardiography.Cardiovasc Eng Tech. 2012; 3: 402-412Crossref Scopus (13) Google Scholar]. No patient has undergone reoperation for SAM [7Lawrie G.M. Earle E.A. Earle N.R. Intermediate-term results of a nonresectional dynamic repair technique in 662 patients with mitral valve prolapse and mitral regurgitation.J Thorac Cardiovasc Surg. 2011; 141: 368-376Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar]. Preservation of normal annular dynamics eliminates the need for leaflet resection and enables the repair rate to rise to 100%, with 90% durability at 10 years by echo. We believe that optimal annular function is the essential foundation for reproducibly excellent results. Simplici-T Annuloplasty Band for Mitral Valve Repair for Degenerative DiseaseThe Annals of Thoracic SurgeryVol. 98Issue 5PreviewSizing of annuloplasty rings and bands is variably based on intertrigonal or intercommissural distances or estimation of the anterior leaflet area. This study examines the results of mitral valve repair with Simplici-T annuloplasty band without predetermining its length in patients with mitral regurgitation (MR) as a result of degenerative disease. Full-Text PDF

Aortic Root Dimensions Among Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

The aim of this study was to characterize aortic root dimensions of patients with aortic valve stenosis undergoing transcatheter aortic valve replacement (TAVR) and to evaluate sex differences. The advent of TAVR makes a precise delineation of the aortic root anatomy mandatory and requires a profound anatomic understanding. Patients planned to undergo TAVR underwent screening imaging with use of a 64-slice or dual-source electrocardiogram-gated contrast-enhanced computed tomography. Anatomic dimensions were assessed at the level of the left ventricular outflow tract (LVOT), annulus, sinus of Valsalva, and ascending aorta. The study population comprised 80 men and 97 women (age: 82 ± 6 years) with symptomatic severe aortic valve stenosis. Multislice computed tomography aortic root assessment revealed larger annular and LVOT dimensions in men than women (area annulus: 483.1 ± 75.6 mm(2) vs. 386.9 ± 58.5 mm(2), p = 0.0002; area LVOT: 478.2 ± 131.0 mm(2) vs. 374.0 ± 94.2 mm(2), p = 0.0024), whereas dimensions of the ascending aorta were comparable. Both LVOT and annulus were predominantly oval without sex differences, with a higher mean ellipticity index for the LVOT compared with the annulus (1.49 ± 0.2 vs. 1.29 ± 0.1); the ascending aorta was primarily circular (1.07 ± 0.1). Although similar in mean surface area, an area mismatch of annulus and LVOT of more than 10%, 20%, and 40% was detected in 42, 9, and 2 patients, respectively. The mean distance from annulus to the left coronary ostium was smaller than the mean distance of the right coronary ostium (14.4 ± 3.6 mm vs. 16.7 ± 3.6 mm), and distances were lower among women than men. The aortic root has specific anatomic characteristics, which affect device design, selection, and clinical outcome in patients undergoing TAVR. Female sex is associated with smaller annular and LVOT but not aortic dimensions. The degree of ellipticity as well as a significant mismatch between annular and LVOT dimensions in selected patients deserve careful evaluation.

Long‐Term Follow‐up Impact of Dual‐Chamber Pacing on Patients with Hypertrophic Obstructive Cardiomyopathy

Pacing has been proposed as a treatment for patients with hypertrophic obstructive cardiomyopathy (HOCM), but there are few studies with long-term follow-up. We evaluated the long-term effects of dual-chamber pacing therapy for patients with HOCM, and to identify the most prognosis-specific factors for predicting outcome in such treating methods. A total of 37 HOCM patients implanted with dual-chamber pacemakers were enrolled consecutively and followed-up. Thirty-seven cases were followed for 1 year, 26 cases for 2 years, 10 cases for 3 years, and eight cases for 4 years. At each annual point of follow-up after pacemaker implantation, the pacing frequency, pacing threshold, impedance, atrioventricular delay, and cumulative percentage of atrial and ventricular pacing were tested, respectively. In addition, left atrial dimension (LAD), left ventricular end diastolic dimension (LVEDd), left ventricular posterior wall thickness (LVPW), interventricular septum thickness (IVS), left ventricular outflow tract dimension (LVOTd), peak velocity of left ventricular outflow tract (VLVOT), left ventricular outflow tract pressure gradient (LVOTPG), left ventricular ejection fraction (LVEF), and pulmonary artery systolic pressure (PASP) were measured. Mitral valve systolic anterior motion (SAM) was also observed. Pacing parameters and echocardiography indexes before and after pacemaker implantation were dynamically compared. Pacing frequency and atrioventricular delay were adjusted to 60-70 beats per minute and 90-180 ms, respectively, in order to ensure the ratio of ventricular pacing was more than 98%. Pacing threshold and pacing impedance were kept in normal ranges. The differences of various pacing parameters were of no statistical significance within the 4 years of follow-up (P > 0.05). Compared with prior to pacing, it was observed that the IVS, VLVOT, and LVOTPG declined significantly (P < 0.01), the LVOTd widened significantly (P < 0.01), and the SAM phenomenon improved obviously (P < 0.01) at 1, 2, 3, and 4 years after pacemaker implantation. Additionally, the changes in LAD, LVEDd, LVPW, LVEF, and PASP were statistically insignificant (P > 0.05). The cardiac structural reconstruction in patients with HOCM can be chronically improved by dual-chamber pacing therapy. The IVS, LVOTd, VLVOT, and LVOTPG can be used as sensitive and specific factors in evaluating the long-term effects of dual-chamber pacing therapy for HOCM.

Left Ventricular Outflow Tract after Kawashima Intraventricular Rerouting

Left ventricular outflow tract obstruction is a concern in the long term after Kawashima intraventricular rerouting for Taussig-Bing anomaly. This study assessed the late results and left ventricular outflow tract dimensions after intraventricular rerouting for Taussig-Bing anomaly in 6 children. Age at operation ranged from 8 months to 7 years. The shortest distance from the tricuspid valve to the pulmonary valve ranged from 8 to 18 mm, which was 79%-139% of the normal aortic annulus diameter. All patients survived the operation, but one died of chronic heart failure 4 months after repair. Three patients had no left ventricular outflow tract obstruction 15 to 31 years after repair, and 2 had significant obstruction at 9 and 14 years. One patient underwent successful revision of the intraventricular baffle; the distance between the tricuspid and pulmonary valves was 16 mm (108% of the normal aortic annulus) although it had been 8 mm (79%) at the initial repair. Late results of intraventricular rerouting were considered favorable.

Severe Subaortic Stenosis

Severe Subaortic Stenosis

Clinical Outcome and Echocardiographic Predictors of Aortic Valve Replacement in Patients with Bicuspid Aortic Valve

Clinical outcomes and echocardiographic parameters associated with aortic valve replacement (AVR) for bicuspid aortic valve are scarce. We conducted retrospective analysis of 208 adults with bicuspid aortic valve referred for transthoracic echocardiograms. The Kaplan-Meier survival free of death or need for cardiac surgery was 72% at 5 years. Cardiac surgery was performed in 19%, the majority (68%) for symptomatic aortic stenosis. Peak gradient 80 mm Hg or greater (hazard ratio 11.8, 95% confidence interval 3.7-37.8, P < .0001) and aortic valve area less than or equal to 0.75 cm(2) (hazard ratio 2.9, 95% confidence interval 1.0-8.5, P = .05) predicted the need for AVR. Patients with a large (54%) versus normal left ventricular outflow tract dimension underwent AVR for symptomatic aortic stenosis at a larger calculated aortic valve area (1.07 +/- 0.21 vs 0.75 +/- 0.18 cm(2), P < .0001) but at a similar peak gradient and velocity ratio (76 +/- 19 vs 76 +/- 22 mm Hg, P = not significant; 0.23 +/- 0.06 vs 0.26 +/- 0.12, P = not significant, respectively). Clinical events are common among patients with bicuspid aortic valve. Peak gradient 80 mm Hg or more and aortic valve area less than or equal to 0.75 cm(2) predicts the need for AVR. Gradients and velocity ratio better reflect the hemodynamic burden of aortic stenosis in patients with a large left ventricular outflow tract.

Planimetric Assessment of Anatomic Valve Area Overestimates Effective Orifice Area in Bicuspid Aortic Stenosis

Although the continuity equation remains the noninvasive standard, planimetry using transesophageal echocardiography is often used to assess valve area for patients with aortic stenosis (AS). Not uncommonly, however, anatomic valve area (AVAA) obtained by planimetry overestimates continuity-derived effective valve area (AVAE) in bicuspid AS. Transthoracic Doppler and transesophageal echocardiography were performed to obtain AVAE and AVAA in 31 patients with bicuspid AS (age 61 +/- 11 years) and 22 patients with degenerative tricuspid AS (age 71 +/- 13 years). Aortic root and left ventricular outflow tract dimensions and the directional angle of the stenotic jet were assessed in all patients. Using these data, a computational fluid dynamics model was constructed to test the effect of these variables in determining the relationship between AVAE and AVAA. For patients with tricuspid AS, the correlation between AVAA (1.15 +/- 0.36 cm2) and AVAE (1.13 +/- 0.46 cm2) was excellent (r = 0.91, P < .001, Delta = 0.02 +/- 0.21 cm2). However, AVAA was significantly larger (1.19 +/- 0.35 cm2) than AVAE (0.89 +/- 0.29 cm2) in the bicuspid AS group (r = 0.71, P < .001, Delta = 0.29 +/- 0.25 cm2). Computer simulation demonstrated that the observed discrepancy related to jet eccentricity. For a given anatomic orifice, functional severity tends to be greater in bicuspid AS than in tricuspid AS. This appears to be primarily related to greater jet eccentricity and less pressure recovery.

Substernal epicardial echocardiography: A recommended examination sequence and clinical evaluation in patients undergoing cardiac surgery

Background Substernal epicardial echocardiography is a novel echocardiography window, utilizing a modified mediastinal drain incorporating a sleeve for the insertion of a transesophageal echocardiography probe. Methods Forty-six patients undergoing cardiac surgery from two institutions were evaluated, and an examination sequence was developed. Results An 11-view examination is presented as a consensus between the two institutions. In clinical usage, there were no major complications attributable to use of the device. Minor air leaks occurred in 6 patients, and 2 cases of sternal wound infection occurring in a cluster of infections are reported, but causation was not attributed to use of the device. There were no significant differences in measurements of the aortic valve area, pulmonary artery diameter, left ventricular outflow tract dimension, or the sinotubular junction between substernal and transesophageal examinations. All 16 wall-motion segments were well visualized in most patients with substernal epicardial echocardiography. Conclusions Substernal epicardial echocardiography is a safe device for use in the postoperative environment.

Usefulness of stroke distance by echocardiography as a surrogate marker of cardiac output that is independent of gender and size in a normal population

Left ventricular outflow tract stroke distance (SD) can be measured using pulsed-wave Doppler echocardiography, and is independent of body size. Moreover, persons with structurally normal hearts (heart rate < 55 beats/min) had SD > 0.18 m, and those with a heart rate > 95 beats/min had SD < 0.22 m; outside of these parameters, low- and high-output states are likely to exist, and suspicion of these can be confirmed by calculation of minute distance (normal range 9.7 to 20.5 m/min).