Narrowing Of Left Ventricular Outflow Tract Research Articles

The impact of surgical repair on left ventricular outflow tract in atrioventricular septal defect with common atrioventricular valve orifice

ObjectiveAlthough a narrow left ventricular outflow tract in atrioventricular septal defect is related to its intrinsic morphology, the contribution from the repair technique remains to be quantified. MethodsA total of 108 patients with an atrioventricular septal defect with a common atrioventricular valve orifice were divided into 2 groups: 2-patch (N = 67) and modified 1-patch (N = 41) repair. The left ventricular outflow tract morphometric was analyzed by quantifying the degree of disproportion between subaortic and aortic annular dimensions (disproportionate morphometrics ratio was defined as ≤ 0.9). Z-scores (median, interquartile range) were further analyzed in a subset of 80 patients with immediate preoperative and postoperative echocardiography. A total of 44 subjects with ventricular septal defects served as controls. ResultsBefore repair, 13 patients (12%) with an atrioventricular septal defect had disproportionate morphometrics (vs 6 [14%] ventricular septal defect P = .79), but the subaortic Z-score (−0.53, −1.07 to 0.06) was lower than the ventricular septal defect (0.07, −0.57 to 1.17; P < .001). After repair, both 2-patch (8 [12%] preoperatively vs 25 [37%] postoperatively; P = .001) and modified 1-patch (5 [12%] vs 21 [51%], P < .001) procedures showed a greater degree of disproportionate morphometrics. Both 2-patch (postoperatively −0.73, −1.56 to 0.08 vs preoperatively −0.43, −0.98 to 0.28; P = .011) and modified 1-patch (−1.42, −2.63 to –0.78 vs −0.70, −1.18 to −0.25; P = .001) procedures also demonstrated lower subaortic Z-scores postrepair. The postrepair subaortic Z-scores were lower in the modified 1-patch group (–1.42 [−2.63 to −0.78]) compared with the 2-patch group (–0.73 [−1.56 to 0.08]; P = .004). Low postrepair subaortic Z-scores (<−2) were observed in 12 patients (41%) in the modified 1-patch group and 6 patients (12%) in the 2-patch group (P = .004). ConclusionsSurgical correction resulted in greater disproportionate morphometrics seen immediately postrepair. The impact on the left ventricular outflow tract was observed in all repair techniques, with a greater burden seen after modified 1-patch repair. Video AbstractThis morphometric study in AVSD with common atrio-ventricular valve orifice confirmed further derangements of LV outflow tract morphometrics immediately after surgical repair.

Diversity and determinants of the sigmoid septum and its impact on morphology of the outflow tract as revealed using cardiac computed tomography.

The sigmoid septum has been generally evaluated subjectively and qualitatively, without detailed examination of its diversity, impact on the morphology of the left ventricular outflow tract (LVOT), and anatomical background. We enrolled 100 patients without any background cardiac diseases (67.5 ± 12.8 years old; 43% women) who underwent cardiac computed tomography. Basal septal morphology was evaluated using antero-superior and medial bulging angles (bidirectional angulation of the basal septum relative to the LVOT). The eccentricity index of the LVOT, area narrowing ratio (LVOT/virtual basal ring area), aortic-to-left ventricular axial angle (angulation of the aortic root relative to the left ventricle), and wedged height (non-coronary aortic sinus to inferior epicardium distance) were also quantified. The antero-superior bulging, medial bulging, aortic-to-left ventricular axial angles, LVOT eccentricity index, area narrowing ratio, and wedged height were 76° ± 17°, 166° ± 27°, 127° ± 9°, 1.8 ± 0.5, 1.0 ± 0.2, and 41.2 ± 9.1mm, respectively. Both bulging angles were correlated with each other and contributed to the narrowing and deformation of the LVOT. Angulated aortic root was not correlated with either bidirectional septal bulge or LVOT narrowing. Clockwise rotation of the aortic root rotation was an independent predictor of prominent antero-superior septal bulge. Deeper aortic wedging was a common independent predictor of bidirectional septal bulge. The extent of septal bulge varies in normal hearts. Along with deep aortic wedging, the bidirectional bulge of the basal septum deforms and narrows the LVOT without affecting the virtual basal ring morphology.

Hemolysis after transcatheter mitral valve replacement in degenerated bioprostheses, annuloplasty rings, and mitral annular calcification: Incidence, patient characteristics, and clinical outcomes.

To determine the incidence, characteristics, and outcomes of patients with hemolysis after transcatheter mitral valve replacement (TMVR). Hemolysis is an increasingly recognized complication of TMVR. Clinical outcomes and optimal management for patients with hemolysis after TMVR are unclear. Patients that underwent mitral valve-in-valve (MViV), valve-in-ring (MViR), and valve-in-mitral annular calcification (ViMAC) at a single center were retrospectively assessed. A total of 101 patients had TMVR, including 69 with MViV, 14 with MViR, and 18 with ViMAC. ViMAC patients had an increased frequency of mild or greater paravalvular leak (PVL) (ViMAC, 72.2%; MViR, 14.3%; MViV, 13.0%; p < .001). Hemolysis occurred in eight patients and was more common after ViMAC (ViMAC, 33.3%; MViR, 7.1%; MViV, 1.5%; p < .001). This required transfusion in five (ViMAC, 4; MViV, 1) and was associated with acute kidney injury in five with ViMAC. Among the ViMAC patients, four had transcatheter re-intervention to treat hemolysis with resolution of anemia in three and mild residual anemia in one with persistent mild PVL. The two ViMAC patients without re-intervention had persistent anemia and died within 6months. Both MViV and MViR patients with hemolysis did not have PVL but had turbulent flow from left ventricular outflow tract narrowing and their hemolysis was self-limited. Hemolysis occurs with greater frequency and increased clinical severity after ViMAC as compared to MViV or MViR and is likely related to increased incidence of PVL. These findings demonstrate the need to investigate novel strategies that can reduce the burden of hemolysis with ViMAC.

Left ventricular outflow tract area after percutaneous transseptal transcatheter mitral valve implantation: A three‐dimensional transesophageal echocardiography study

Left ventricular (LV) outflow tract (LVOT) obstruction increases mortality in patients undergoing transcatheter mitral valve implantation (TMVI) in degenerated bioprostheses, annuloplasty rings, and native mitral valves. We aimed to evaluate the LVOT area after TMVI using 3-dimensional (3D) transesophageal echocardiography (TEE) and to investigate the preprocedural cardiac geometry that affects the LVOT area after TMVI. We retrospectively reviewed echocardiography data in 43 patients who had TMVI. A change in pressure gradient across LVOT from before to after TMVI (∆PG) and postprocedure 3D LVOT cross-sectional area at the level of the most distal portion of the mitral valve stent that was closest to the LV apex were assessed as evidence of LVOT narrowing. Transcatheter mitral valve implantation with the use of balloon-expandable valve system was performed for 24 bioprostheses, 7 annuloplasty rings, and 12 native valves. Compared to patients without increase in LVOT gradient (∆PG <10mm Hg; n=33), patients with increase in LVOT gradient (∆PG ≥10mm Hg; n=10) had smaller LV end-systolic volume (LVESV), greater LV ejection fraction (LVEF), and smaller aorto-mitral (AM) angle. The LVOT area at the valve stent distal edge showed strong association with ∆PG (r=-.68, P<.0001). Only a small AM angle was associated with a small LVOT area at the valve stent distal edge on multivariable analysis, independent of LVESV and LVEF. Small LV size, preserved LVEF, and small AM angle were associated with LVOT narrowing. 3D-derived AM angle might be independently associated with LVOT narrowing in patients undergoing transcatheter mitral valve-in-valve, valve-in-ring, and valve-in-native valve implantation, independent of LVESV and LVEF.

Use of the Konno Procedure in an 80-year-old Woman with Aortic Stenosis, a Narrow Left Ventricular Outflow Tract, and a Small Aortic Annulus

This report describes a technique for repairing an aortic stenosis in an elderly patient with a small aortic annulus and a narrow left ventricular outflow tract. Preoperative echocardiography in an 80-year-old woman showed severe aortic stenosis with a narrow outflow tract: the aortic valve area was 0.48 cm(2), the aortic annular diameter was 14 mm, and the left ventricular outflow tract diameter was 14 mm. The Konno procedure was used to enlarge both the small aortic annulus and the left ventricular outflow tract, and a 19-mm Carpentier-Edwards bioprosthetic valve was implanted. The patient's postoperative course was uneventful. The left ventricular mass decreased from a preoperative value of 236 g to 96 g, 3 years after surgery. Only a few reports have described the use of the Konno operation in adult patients. In the present case, the Konno operation was demonstrated to be a good option for aortic stenosis accompanied by a small aortic annulus and a narrow left ventricular outflow tract, even in an elderly patient.

Factors associated with cardiac conduction disorders and permanent pacemaker implantation after percutaneous aortic valve implantation with the CoreValve prosthesis

Cardiac conduction disorders and requirement for permanent pacemaker implantation (PPI) are not uncommon after surgical aortic valve replacement and have important clinical implications. We aimed to investigate the incidence of cardiac conduction disorders after percutaneous aortic valve implantation (PAVI) and to identify possible clinical factors associated with their development. We studied 34 patients (mean age 80 +/- 8 years, 18 male) who underwent PAVI with the CoreValve bioprosthesis (Corevalve Inc, Irvine, CA). Electrocardiographic evaluation was performed pre- and postprocedurally, and at 1-week and 1-month follow-up. Other clinical variables were obtained from the medical history, echocardiography, and angiography. After PAVI, 7 patients required PPI, all of whom developed total atrioventricular block within 3 days postprocedurally. A smaller left ventricular outflow tract diameter (20.3 +/- 0.5 vs 21.6 +/- 1.8 cm, P = .01), more left-sided heart axis (-20 degrees +/- 29 degrees vs 19 degrees +/- 36 degrees , P = .02), more mitral annular calcification (10 +/- 1 vs 5 +/- 4 mm, P = .008), and a smaller postimplantation indexed effective orifice area (0.86 +/- 0.20 vs 1.10 +/- 0.26 cm(2)/m(2), P = .04) were associated with PPI. The incidence of new left bundle-branch block (LBBB) was 65% and was associated with a deeper implantation of the prosthesis: 10.2 +/- 2.3 mm in the new-LBBB group versus 7.7 +/- 3.1 mm in the non-LBBB group (P = .02). Percutaneous aortic valve implantation with the CoreValve prosthesis results in a high incidence of total atrioventricular block requiring PPI and new-onset LBBB. Preexisting disturbance of cardiac conduction, a narrow left ventricular outflow tract, and the severity of mitral annular calcification predict the need for permanent pacing, whereas the only factor shown to be predictive for new-onset LBBB is the depth of prosthesis implantation.

Systolic Anterior Motion of the Mitral Valve After Aortic Valve Replacement for Aortic Insufficiency

INTRAOPERATIVE SYSTOLIC ANTERIOR motion of the mitral valve (SAM) after aortic valve replacement (AVR) for aortic stenosis has been previously described.1,2 The presence of concentric left ventricular hypertrophy (LVH), a relatively narrow left ventricular outflow tract (LVOT), and increased blood flow velocity in the LVOT when coupled with perioperative hypovolemia and/or vasodilatation place patients with aortic stenosis at risk for SAM. Alternatively, patients with aortic insufficiency (AI) are much less likely to develop SAM because this regurgitant lesion is most often associated with a dilated left ventricle (LV) and the LVOT widens during systole preventing apposition of the anterior leaflet.

Asymmetry of Systolic Anterior Motion of the Mitral Valve in Patients with Hypertrophic Obstructive Cardiomyopathy: A Real-time Three-dimensional Echocardiographic Study

By geometric analysis of real-time 3-dimensional echocardiography performed in 39 patients with hypertrophic obstructive cardiomyopathy and definite systolic anterior motion of the mitral valve, we found that the angle between the mitral annular plane and basal portion of the anterior mitral valve leaflet, and the angle between the basal portion of the anterior leaflet and its tip portion measured in the medial and central anteroposterior planes, were significantly smaller than those in the lateral plane. The distance between the interventricular septum and the anterior mitral valve tip in the medial and central plane was also significantly smaller than that in the lateral plane. The lateral distance between the interventricular septum and the anterior mitral valve tip was the only independent determinant of left ventricular outflow tract pressure gradient by multiple stepwise regression analysis. In conclusion, systolic anterior motion of the mitral valve develops predominantly in the medial side, resulting in laterally located narrow left ventricular outflow tract opening in patients with hypertrophic obstructive cardiomyopathy.

Echocardiographic Study on the Origin of the Innocent Flow Murmurs

To investigate the origin of the pulmonary systolic ejection innocent flow murmur (IFM), echocardiographic examinations were undertaken in 30 children with IFM and in a control group consisting of 28 healthy children without murmur. Compared to the controls, the diameters of the left ventricular outflow tract (LVOT) and aortic valve annulus and aortic valve area tended to be smaller, whereas stroke volume (SV) and cardiac output were slightly greater in children with IFM, but they were not statistically significant. Mean fractional shortening was significantly higher in children with IFM. Peak flow velocity of LVOT, right ventricular outflow tract, aorta, and pulmonary artery, mean velocity and velocity time integral of the aortic and pulmonary flow, and maximal acceleration of the aortic flow were all significantly higher in the IFM group compared to the controls. The variables of left-sided flow velocities in the same individuals with IFM were significantly higher compared to those derived from the right heart. The ratios of the SV to the LVOT diameter and to the aortic valve area were found to be significantly greater. It was concluded that IFM originates from higher blood flow velocities in the region of LVOT and aortic valve annulus, and that the increased flow velocity results from the larger SV passing through the relatively narrow LVOT and aortic valve in children with IFM.

Is Prosthesis–Patient Mismatch a Clinically Relevant Entity?

In this issue of Circulation , Koch and associates1 from the Cleveland Clinic published a study on the relationship between prosthetic valve size and the Duke Activity Status Index (DASI) after aortic valve replacement (AVR). The study was conducted with 1014 patients operated on from 1995 through 1998, completed 1 year later, and published now. DASI scores increased from a mean of 29 preoperatively to 46 postoperatively after a mean follow-up of 8.3 months. The investigators could find no obvious relationship between prosthetic valve size and postoperative DASI score. One of the limitations of the study was that prosthetic valve gradients and effective orifice areas were not measured by echocardiography to quantify prosthesis–patient mismatch. It is also interesting to note that more than two thirds of the patients were in New York Heart Association functional classes I and II preoperatively, and yet the DASI mean score before surgery was only 29 out of a maximum of 58.2. For this reason alone, it must be assumed that factors other than the aortic valve disease played a role in the DASI score. Nevertheless, this is not the first study to suggest that valve size plays no role in the clinical outcomes of AVR. See p 3221 Valve prosthesis–patient mismatch (PPM) is a term introduced by Rahimtoola in 1978 to describe a condition in which the in vivo prosthetic valve effective orifice area is smaller than that of the native valve.2 According to this broad definition, every patient with a prosthetic heart valve has PPM because the leaflets of both mechanical and bioprosthetic valves are mounted into frames that occupy …

Gender differences in patients with severe aortic stenosis: impact on preoperative left ventricular geometry and function, as well as early postoperative morbidity and mortality

In patients with severe aortic stenosis, we studied the impact of gender on preoperative left ventricular geometry and function, as well as on early postoperative mortality and morbidity. Prospective Doppler echocardiographic evaluation was performed in 99 female patients and 96 males. The patients had severe aortic stenosis and the mean pressure gradients were similar in females and males. Left ventricular diastolic volume adjusted for body surface area (BSA) was larger in males, 55+/-17.4 ml/m2 versus 43+/-13.1 mL/m2 (mean+/-standard deviation; P = 0.0001). The ejection fraction was similar in females (55+/-14%) and males (55+/-13%), and patients of both sexes had significantly lower stroke volume and cardiac index than healthy controls. The relative wall thickness (wall thickness/diastolic diameter ratio) was higher (P = 0.03) in females (0.47+/-0.10) than in males (0.43+/-0.10) Consequently, the diastolic diameter/wall thickness ratio (a substitute for wall tension) was higher (P = 0.02) in males (4.2+/-0.99) than in females (3.9+/-0.80). Compared with survivors, patients who died within 30 days of the operation (n = 17, 11 females) had a smaller body surface area (1.70+/-0.19 vs. 1.82+/-0.19 m2, P = 0.012), smaller left ventricular outflow tract (20.8+/-0.21 vs. 22.0+/-0.22 mm, P = 0.023), higher incidence of abnormal intraventricular flow velocity (33 vs. 8%, P = 0.018) and increased relative wall thickness (0.52+/-0.17 vs. 0.45+/-0.09 P = 0.039). Gender was of no independent importance for early mortality when age and left ventricular outflow tract diameter were accounted for. Cardiac adaptation to aortic stenosis seems to be influenced by gender, males presenting larger left ventricular volumes and higher wall tension. The echocardiographic findings of a narrow left ventricular outflow tract, abnormally increased intraventricular velocity and increased relative wall thickness identified patients with increased risk of early postoperative mortality. However gender had no independent impact on early postoperative outcome.

The Surgical Anatomy of the Left Ventricular Outflow Tract in Hearts With Ventricular Septal Defect and Aortic Arch Obstruction

Background. Profound understanding of the left ventricular outflow tract (LVOT) anatomy is crucial to improve surgical results in patients with aortic arch obstruction, ventricular septal defect, and subaortic stenosis. Methods. We studied the morphology of the LVOT in 32 postmortem hearts with aortic arch obstruction and a ventricular septal defect. In case of subaortic obstruction, the length of the subaortic muscular component was measured anteriorly and posteriorly within the left ventricle. Results. Seven of the 32 hearts had no subaortic stenosis. Nine had aortic override, which caused LVOT narrowing. Sixteen hearts contained a subaortic shelf, downstream to the ventricular septal defect, which deviated into the left ventricle in 15. In 10 of these the shelf was muscular; in 6 it was a fibrous ridge. In cases with a muscular shelf, the posterior part was significantly shorter than the anterior part ( p < 0.004). In 9 hearts the LVOT was further narrowed because of the abnormal relationship between the mitral valve and the subaortic shelf. Conclusions. The present study confirms the complexity of LVOT stenosis in aortic arch obstruction and ventricular septal defect and provides a better understanding of the options to achieve surgical relief.

Severe left ventricular outflow tract obstruction despite sliding leaflet technique for repair of the mitral valve

Reconstructive surgery of the mitral valve has become the procedure of choice for mitral valve disease. In our center, the prevalence of reconstructive mitral valve surgery increased to 30% (42/139) in 1994. Systolic anterior motion of the mitra] valve causing left ventricular outflow tract obstruction (LVOTO) after repair of the valve occurs in 1% to 6% of cases. 1-5 Risk factors for the occurrence of LVOTO include degenerative mitral insufficiency with excess leaflet tissue, nondilatated left ventricular cavity, narrow mitral valve-aorta angle, use of a rigid mitroplasty ring, and nonuse of the sliding leaflet technique) -5 We report a case in which LVOTO occurred in a high-risk patient despite our use of the sliding leaflet technique, with severe consequences. A 59-year-old woman was referred to our surgical unit with a long-standing history of mitral insufficiency. Echocardiography had revealed prolapse of both anterior and posterior mitral leaflets, with myxomatous degenerative changes resulting in severe mitral regurgitation. Angiography confirmed these findings and also showed smooth coronary arteries and preserved left ventricular function. A narrow left ventricular outflow tract was noted, but no gradient was measured. On May i8, 1995, a reconstructive mitral valve operation was performed. The mitral valve was exposed through a superior septal approach, and retrograde bloodcardioplegia was used for myocardial protection. Because of prolapse of the posterior leaflet and rupture of one chorda, two quadrangular resections of the posterior leaflet were necessary. The defect was closed with the sliding leaflet technique. In addition, a prolonged chorda of the anterior leaflet was shortened by invagination of its excess length in the papillary muscle. The repair was concluded with a size 32 Carpentier annuloplasty ring (Baxter, Healthcare Corp., Deerfield, Ill.). Perioperative surgical and echocardiographic control showed no remaining insufficiency. The patient was easily weaned from the extracorporeal circulation but while she was still in the operating room, low cardiac output developed (cardiac index 2.38 L. min~ • m -2) and was initially treated with positive inotropic support. Echocardiography revealed septal anterior motion with narrowing of the left ventricular outflow

Morphological characterisation of ventricular septal defects associated with coarctation of aorta by cross-sectional echocardiography.

Cross-sectional echocardiograms of 18 neonates and infants with coarctation of the aorta and ventricular septal defect were retrospectively assessed. With a combination of subcostal and precordial cuts the site and anatomical relations of the defects were determined. In one case there was a muscular trabecular ventricular septal defect. Three had a malalignment defect with associated left ventricular outflow tract obstruction. In two there was a doubly committed subarterial defect with associated malalignment of the point of continuity between the aortic and pulmonary valves and the crest of the trabecular septum. Twelve cases had a perimembranous defect, with varying degrees of extension into the inlet, trabecular, or outlet septum. In this group 10 had associated aortic override, with varying degrees of left ventricular outflow tract narrowing. Abnormal insertion of the tricuspid valve was observed in 10 cases, such that it partly obscured the ventricular septal defect. Thus in most cases of coarctation with ventricular septal defect, the morphology of the ventricular septal defect and ventricular outflow tracts is such that left ventricular ejection is directed towards the pulmonary artery rather than the aorta.

The role of echocardiography in the selection of mitral valve prosthesis

Assessment of the left ventricular outflow tract was made echographically in 70 patients who subsequently received a mitral prosthesis. Group A (44 patients) had normal left ventricular outflow tract width (> 20 mm.); 13 received the Starr-Edwards prosthesis and nine received the Braunwald-Cutter prosthesis. There were two patients with low cardiac output syndrome and no hospital deaths. Group B (26 patients) had a narrow left ventricular outflow tract (<20 mm.). Thirteen patients received the Starr-Edwards prosthesis. One patient had low cardiac output syndrome, and there were no hospital deaths. We conclude that the use of the ball-and-cage prosthesis in the mitral position in patients with a narrowed left ventricular outflow tract (<20 mm.) measured echographically is not associated with an increased surgical risk.

TWO‐DIMENSIONAL ECHOCARDIOGRAPHY IN ATRIOVENTRICULAR CANAL MALFORMATION: A DIAGNOSTIC APPROACH

Two-dimensional echocardiographic studies were performed in 20 children with various forms of atrio-ventricular canal malformation. Both sagittal and transverse cross-sections were evaluated. The most typical finding in all patients was the visualization of the cleft anterior mitral leaflet (AML) represented by a diastolic break of AML echoes in the sagittal cross-section. - In cases where the AML is attached to the interventricular septum, varying degrees of left ventricular outflow tract narrowing and elongation were observed. In the transverse cross-section mitral-tricuspid alignment could be observed at the level of the aortic root. The ventricular septal defect in complete AVC was visualized as an echo-free space between the common anterior leaflet and the interventricular septum.

Echocardiography in the diagnosis of idiopathic hypertrophic subaortic stenosis co-existing with aortic valve disease.

Echocardiographic studies demonstrated the presence of co-existing idiopathic hypertrophic subaortic stenosis (IHSS) in six patients with aortic valve disease (four calcific aortic stenosis, two pure aortic incompetence). The characteristics of IHSS were a narrow left ventricular outflow tract, a systolic anterior movement of the mitral valve (SAM), and asymmetric ventricular septal hypertrophy. Large SAMs were observed in two patients with pure aortic incompetence and one with aortic stenosis. Relatively small, inconstant, and often incomplete SAMs were noted in the remaining three patients with aortic stenosis. In contrast to isolated IHSS, the small SAMs observed in this group did not become prominent with the Valsalva maneuver or amyl nitrite inhalation. These features may be related to the afterload provided by the fixed, distal stenosis. Echocardiographic evidence of aortic valve disease was present in all patients. Clinically, co-existence of IHSS was not suspected in five patients. Associated IHSS was established using provocative measures during cardiac catheterization in three cases, while in the remainder it was substantiated at surgery. Three of four patients who underwent myotomy/myectomy concomitant with aortic valve replacement survived and postoperative echocardiographic studies revealed complete absence of SAMs in two of them. Echocardiography appears to be useful in the diagnosis of associated IHSS in the presence of aortic valve disease.