Three-dimensional anatomic features of the mitral valve that predict systolic anterior motion occurring during dobutamine stress echocardiography.

BACKGROUND/AIM: Left ventricular outflow tract obstruction related to systolic anterior motion (SAM) of the mitral valve is a common complication of dobutamine stress echocardiography (DSE). However, the mechanisms underlying SAM have not been fully characterized. The objective of the present study was to use three-dimensional echocardiography to identify anatomic features of the mitral valve that predispose to SAM during DSE. METHODS: We retrospectively evaluated consecutive patients included prospectively in our database and who had undergone 3D echocardiography (including an assessment of the mitral valve) before DSE. Patients who had developed SAM during DSE (the SAM+ group) were matched 2:3 with patients who did not (the SAM- group). RESULTS: One hundred patients were included (mean age: 67 ± 10). Compared with SAM- patients (n = 60), SAM+ patients (n = 40) had a lower mitral annular area, a smaller perimeter, and a smaller diameter (p < .01 for all, except the anteroposterior diameter). The SAM+ group had also a narrower mitral-aortic angle (126 ± 12° vs. 139 ± 11° in the SAM- group; p < .01) and a higher posterior mitral leaflet length (1.4 ± .27 cm vs. 1.25 ± .29, respectively; p < .01). Furthermore, the mitral annulus was more spherical, more flexible, and more dynamic in SAM+ patients than in SAM- patients (p < .05 for all). In a multivariate analysis of anatomic variables, the mitral-aortic angle, the mitral annular area, and posterior leaflet length were independent predictors of SAM (p ≤ .01 for all). In a multivariate analysis of standard echo and hemodynamic variables, the presence of wall motion abnormalities at rest (p < .01) was an independent predictor of SAM. CONCLUSION: SAM during DSE is multifactorial. In addition to the pharmacologic effects of dobutamine on the myocardium, 3D echocardiographic features of the mitral valve (a smaller mitral annulus, a narrower mitral-aortic angle, and a longer posterior leaflet) appear to predispose to SAM.

Perioperative echocardiography in minimally invasive surgery for hypertrophic obstructive cardiomyopathy.

BACKGROUND: Hypertrophic obstructive cardiomyopathy (HOCM) is clinically symptomatic and prone to malignant arrhythmias and sudden cardiac death (SCD). Currently, an effective treatment is surgical resection of the hypertrophic ventricular septum to relieve the left ventricular outflow tract (LVOT) obstruction and mitral insufficiency. Our center performs an innovative, minimally invasive right infra-axillary thoracotomy for transaortic septal myectomy. Minimally invasive procedures rely more on perioperative transesophageal echocardiography (TEE). This study aimed to explore the use of echocardiography during the perioperative period of surgical intervention for HOCM. METHODS: Between August 2021 and April 2022, 27 patients with HOCM underwent cardiac surgery at our hospital. Minimally invasive transaortic septal resection (Morrow myectomy) was performed from the right axilla. The extent of myectomy and need for mitral valve repair were based on perioperative TEE assessment and surgical findings. The demographic parameters and clinical data of patients were recorded. The cardiopulmonary bypass time, aortic cross-clamp, and mechanical ventilation times were calculated. TEE was used to assess ventricular wall thickening and anatomical abnormalities of mitral regurgitation, assist in intravenous catheterization, and assess the postoperative gradients of the LVOT. RESULTS: Among the 27 patients with HOCM who underwent transaortic septal myectomy by minimally invasive right infra-axillary thoracotomy, 16 had LVOT obstruction, 2 had mid-LV obstruction, and 9 had both LVOT and mid-LV involvement. TEE provides information about the fine structure of the LV cavity and the etiology of the obstruction. In all cases, LVOT obstruction and mitral valve systolic anterior motion were resolved postoperatively, and the degree of mitral regurgitation was significantly reduced. CONCLUSION: Perioperative echocardiography provides valuable information regarding the complex etiology of LVOT obstruction during minimally invasive right infra-axillary thoracotomy for transaortic septal myectomy. It helps determine the extent of septal resection and assess the need for concomitant mitral valve repair.

Systolic anterior motion of a transatrial transcatheter mitral valve replacement causing left ventricular outflow tract obstruction.

Transatrial transcatheter mitral valve replacement is a hybrid strategy involving placing the patient on cardiopulmonary bypass and direct implantation of a transcatheter valve in a calcified annulus for mitral annular calcification. We report a rare phenomenon of systolic anterior motion of the leaflets of a transcatheter heart valve prosthesis used for mitral valve replacement causing left ventricular outflow tract obstruction. Although reported in transcatheter mitral valve replacement, we believe this is the first report of left ventricular outflow tract obstruction after transatrial mitral valve replacement and discuss the pre-disposing risk factors.

Unexpected systolic anterior motion of the mitral valve-related hypoxemia during transurethral resection of the prostate under spinal anesthesia: a case report.

BACKGROUND: Dynamic obstruction of the left ventricular outflow tract resulting from systolic anterior motion of the mitral valve can be an unexpected cause of acute and severe perioperative hypotension in noncardiac surgery. We report a patient undergoing spinal anesthesia for transurethral resection of the prostate who experienced sudden hypoxemia caused by systolic anterior motion-induced mitral regurgitation but with a clinically picture simulating fluid overload. CASE PRESENTATION: An 83-year-old man with a history of hypertension was scheduled for transurethral resection of the prostate. One hour after spinal anesthesia, he developed acute restlessness and dyspnea, with pink frothy sputum and progressive hypoxemia. Slight hypertension was noted, and an electrocardiogram showed atrial fibrillation with a rapid ventricular response. Furosemide and nitroglycerin were thus administered for suspected fluid overload or transurethral resection of the prostate syndrome; however, he then became severely hypotensive. After tracheal intubation, intraoperative transesophageal echocardiography was promptly performed, which revealed an empty hypercontractile left ventricle, significant mitral regurgitation and mosaic flow signal in the left ventricular outflow tract. Following aggressive fluid therapy, his hemodynamic changes stabilized. Repeat echocardiography in intensive care unit confirmed the presence of systolic anterior motion of the anterior mitral leaflet obstructing the left ventricular outflow tract. We speculate that pulmonary edema was induced by systolic anterior motion-associated mitral regurgitation and rapid atrial fibrillation, and the initial management had worsened his hypovolemia and provoked left ventricular outflow tract obstruction and hemodynamic instability. CONCLUSIONS: Pulmonary edema caused by systolic anterior motion of the mitral valve can be difficult to clinically differentiate from that induced by fluid overload. Therefore, bedside echocardiography is paramount for timely diagnosis and prompt initiation of appropriate therapy in the perioperative care setting.

Incidental TEE finding of aberrant chordae tendineae insertion into the basal septum.

A 65-year-old female with severe mitral regurgitation presenting for mitral valve replacement was found to have a previously undiagnosed aberrant papillary muscle with thickened chordae tendineae inserting into the basal septum during intra-operative TEE. Despite its anatomic location, there was no evidence that the aberrant papillary muscle was contributing to the mitral regurgitation or causing left ventricular outflow tract (LVOT) obstruction. The aberrant papillary muscle was resected during the operation and the patient was separated from cardiopulmonary bypass without complications.

Primeval outcomes of thoracoscopic transmitral myectomy with anterior mitral leaflet extension for hypertrophic obstructive cardiomyopathy.

BACKGROUND: The transaortic Morrow procedure is the current gold standard for hypertrophic obstructive cardiomyopathy (HOCM) patients who are resistant to maximum drug therapy. It is controversial whether concomitant mitral valve intervention is necessary. Only a few centers apply for concomitant anterior mitral leaflet extension with a bovine or autologous pericardial patch to further decrease systolic anterior motion. Our aim is to assess the primeval outcomes of thoracoscopic transmitral myectomy with anterior mitral leaflet extension (TTM-AMLE) in symptomatic HOCM patients. METHODS: Between April 2019 and November 2020, 18 consecutive HOCM patients who underwent TTM-AMLE were enrolled in this study. Preoperative, postoperative, and follow-up outcomes were compared and statistically analyzed. RESULTS: The mean age was (50.17 ± 6.18) years and 10 (55.56%) were males. 18 (100%) patients had mitral regurgitation preoperatively, and they all successfully underwent TTM-AMLE with a median cardiopulmonary bypass and aortic cross-clamp time of 200.0 (150.8, 232.0), and 127.5 (116.0, 149.0) min, respectively. The median length of ICU stay was 2.7 (1.4, 5.2) days. The interventricular septum thickness was significantly reduced (from 18.03 ± 3.02 mm to 11.91 ± 1.66 mm, p < .001). There was no perioperative mortality, perforation of ventricular septum, or conversion to sternotomy observed. During a median follow-up of 18 months (IQR, 5-24 months), 1 (5.56%) patient had severe mitral regurgitation due to patch detachment and received reoperation. Moderate degree of mitral regurgitation and more than 50 mmHg in left ventricular outflow tract gradient were found in 2 (11.11%), and 1 (5.56%) patients, respectively. 1 (5.56%) patient who had second-degree atrioventricular block received permanent pacemaker implantation postoperatively. Overall, the maximum left ventricular outflow tract gradient (88.50 [59.50, 112.75] mmHg vs. 10.50 [7.00, 15.50] mmHg, p = .002), left ventricular outflow tract velocity (4.70 [3.86, 5.33] m/s vs. 1.60 [1.33, 1.95] m/s, p < .001) and the degree of mitral regurgitation (6.99 ± 4.47 cm2 vs. 2.22 ± 1.51 cm2 , p = .001) were significantly decreased, with a significant reduction in the proportion of systolic anterior motion (94.44% vs. 16.67%, p < .001). CONCLUSIONS: The TTM-AMLE is a safe and effective surgical approach for selected patients with HOCM. In our series, it provides excellent relief of left ventricular outflow tract obstruction, while significantly eliminating mitral regurgitation. The early outcomes of TTM-AMLE are satisfactory, but further studies and longer follow-ups are awaited.

Gender Related Differences in the Clinical Presentation of Hypertrophic Cardiomyopathy-An Analysis from the SILICOFCM Database.

Background and Objectives: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease that affects approximately 1 in 500 people. Due to an incomplete disease penetrance associated with numerous factors, HCM is not manifested in all carriers of genetic mutation. Although about two-thirds of patients are male, it seems that female gender is associated with more severe disease phenotype and worse prognosis. The objective of this study was to evaluate the gender related differences in HCM presentation. Materials and Methods: This study was conducted as a part of the international multidisciplinary SILICOFCM project. Clinical information, laboratory analyses, electrocardiography, echocardiography, and genetic testing data were collected for 362 HCM patients from four clinical centers (Florence, Newcastle, Novi Sad, and Regensburg). There were 33% female patients, and 67% male patients. Results: Female patients were older than males (64.5 vs. 53.5 years, p < 0.0005). The male predominance was present across all age groups until the age of 70, when gender distribution became comparable. Females had higher number of symptomatic individuals then males (69% vs. 52%, p = 0.003), most frequently complaining of dyspnea (50% vs. 30%), followed by chest pain (30% vs. 17%), fatigue (26% vs. 13%), palpitations (22% vs. 13%), and syncope (13% vs. 8%). The most common rhythm disorder was atrial fibrillation which was present in a similar number of females and males (19% vs. 13%, p = 0.218). Levels of N-terminal pro-brain natriuretic peptide were comparable between the genders (571 vs. 794 ng/L, p = 0.244). Echocardiography showed similar thickness of interventricular septum (18 vs. 16 mm, p = 0.121) and posterolateral wall (13 vs. 12 mm, p = 0.656), however, females had a lower number of systolic anterior motion (8% vs. 16%, p = 0.020) and other mitral valve abnormalities. Conclusions: Female patients are underrepresented but seem to have a more pronounced clinical presentation of HCM. Therefore, establishing gender specific diagnostic criteria for HCM should be considered.

Echocardiographic and clinical outcomes of patients undergoing septal myectomy plus anterior mitral leaflet extension for hypertrophic cardiomyopathy.

Septal myectomy is indicated in patients with obstructive hypertrophic cardiomyopathy (HCM) and intractable symptoms. Concomitant mitral valve (MV) surgery is performed for abnormalities contributing to systolic anterior motion (SAM), or for SAM-mediated mitral regurgitation (MR) with or without left ventricular outflow tract (LVOT) obstruction. One MV repair technique is anterior mitral leaflet extension (AMLE) utilizing bovine pericardium, stiffening the leaflet and enhancing coaptation posteriorly. Fifteen HCM patients who underwent combined myectomy-AMLE for LVOT obstruction or moderate-to-severe MR between 2009 and 2020 were analyzed using detailed echocardiography. The mean age was 56.6 years and 67% were female. The average peak systolic LVOT gradient and MR grade measured 73.4 mmHg and 2.3, respectively. Indications for myectomy-AMLE were LVOT obstruction and moderate-to-severe MR in 67%, MR only in 20%, and LVOT obstruction only in 13%. There was no mortality observed, and median follow-up was 1.2 years. Two patients had follow-up grade 1 mitral SAM, one of whom also had mild LVOT obstruction. No recurrent MR was observed in 93%, and mild MR in 7%. Compared with preoperative measures, there was a decrease in follow-up LV ejection fraction (68.2 vs 56.3%, p = 0.02) and maximal septal wall thickness (25.5 vs 21.3 mm, p < 0.001), and an increase in the end-diastolic diameter (21.9 vs 24.8 mm/m2, p = 0.04). There was no change in global longitudinal strain (-12.1 vs -11.6%, p = 0.73) and peak LV twist (7.4 vs 7.3°, p = 0.97). In conclusion, myectomy-AMLE is a viable treatment option for carefully selected symptomatic HCM patients with LVOT obstruction or moderate-to-severe MR.

A systematic review and pooled analysis of septal myectomy and edge-to-edge mitral valve repair in obstructive hypertrophic cardiomyopathy.

Left ventricular outflow tract (LVOT) obstruction and systolic anterior motion (SAM) of the mitral valve (MV) occurs in 70% of hypertrophic cardiomyopathy (HCM) patients. In individuals undergoing septal myectomy, concomitant MV surgery is considered for SAM with residual LVOT obstruction or mitral regurgitation (MR); however, the optimal approach remains debated. A literature search was performed in Pubmed, EMBASE, Ovid, and the Cochrane library of published articles through June 2021 reporting on combined septal myectomy and edge-to-edge MV repair for obstructive HCM. Continuous variables were weighted and compared using a student's t-test, and categorical variables using a chi-square test with Yates correction. Six studies with 158 total patients were included. The mean follow-up was 2.8 ± 2.7 years. Compared with pre-operative values, there were significant reductions in the LV ejection fraction (69 ± 10 vs 59 ± 8%), peak LVOT gradient (82 ± 34 vs 16 ± 13 mmHg), prevalence of moderate or greater MR (84 vs 5 %), and presence of SAM (96% vs 0) (p < 0.001 for all). There was no change in LV internal diastolic diameter (4.2 ± 1.3 vs 4.4 ± 1.5 cm, p = 0.32). There were 2 (1%) operative mortalities. At follow-up, the survival rate was 97%, there were 3 (2%) re-operative MV replacements, 4 (3%) patients remained in New York Heart Association functional class III/IV, and 8 (6%) required permanent pacemaker implantation. In conclusion, combined septal myectomy and edge-to-edge MV repair is a safe and effective treatment strategy in carefully selected patients requiring surgical HCM management.

Usefulness of Stress Echocardiography in Assessment of Dynamic Left Ventricular Obstructions: Case Series and Review of the Literature.

Dynamic left ventricular outflow tract obstruction (DLVOTO) or midcavity obstruction in patients with structurally normal hearts is not uncommon in routine clinical practice and can cause significant symptoms mimicking coronary artery disease or heart failure. Although exercise echocardiography is the gold standard for assessing DLVOTO, dobutamine stress echocardiography (DSE) may be valuable diagnostic modality in patients who are unable to exercise or have an uninterpretable 12-lead electrocardiogram. We provide an updated overview of the relevant literature regarding prevalence, pathophysiology, clinical significance, and prognostic impact of DLVOTO and midcavity obstruction in structurally normal hearts. We also present a clinical series of 4 cases of DLVOTO and midcavity obstruction documented by DSE and discuss the value of different kinds of modern stress imaging modalities involving: (1) contrast-enhanced DSE to assess myocardial perfusion and inducible ischemia; (2) adenosine stress echocardiography to assess coronary flow reserve/microvascular dysfunction; and (3) functional imaging with deformation echocardiography to assess subclinical myocardial dysfunction in patients with structurally normal heart and without significant coronary disease. Based upon our own experiences and a critical review of the current literature, we will then present a practical guidance for management of DLVOTO and midcavity obstruction.

Comparisons of simulation results between passive and active fluid structure interaction models for left ventricle in hypertrophic obstructive cardiomyopathy.

BACKGROUND: Patient-specific active fluid-structure interactions (FSI) model is a useful approach to non-invasively investigate the hemodynamics in the heart. However, it takes a lot of effort to obtain the proper external force boundary conditions for active models, which heavily restrained the time-sensitive clinical applications of active computational models. METHODS: The simulation results of 12 passive FSI models based on 6 patients' pre-operative and post-operative CT images were compared with corresponding active models to investigate the differences in hemodynamics and cardiac mechanics between these models. RESULTS: In comparing the passive and active models, it was found that there was no significant difference in pressure difference and shear stress on mitral valve leaflet (MVL) at the pre-SAM time point, but a significant difference was found in wall stress on the inner boundary of left ventricle (endocardium). It was also found that pressure difference on the coapted MVL and the shear stress on MVL were significantly decreased after successful surgery in both active and passive models. CONCLUSION: Our results suggested that the passive models may provide good approximated hemodynamic results at 5% RR interval, which is crucial for analyzing the initiation of systolic anterior motion (SAM). Comparing to active models, the passive models decrease the complexity of the modeling construction and the difficulty of convergence significantly. These findings suggest that, with proper boundary conditions and sufficient clinical data, the passive computational model may be a good substitution model for the active model to perform hemodynamic analysis of the initiation of SAM.

Mitral Valve Disease in Hypertrophic Cardiomyopathy:Evaluation and Management.

PURPOSE OF REVIEW: To discuss the critical role of the mitral valve (MV) in the pathophysiology of obstruction in hypertrophic cardiomyopathy (HCM), evaluation of the MV in HCM, the impact of MV characteristics on treatment in HCM, and management of the MV at the time of septal myectomy. RECENT FINDINGS: Multimodality imaging helps describe mitral abnormalities in HCM, though significant controversy persists on what to do with these abnormalities. In certain cases, intervention on the MV may be necessary, although outcomes may be worse in those who undergo mitral interventions. Thorough assessment of MV anatomy and function is paramount in evaluating a patient with HCM. Emphasis should be placed on thorough evaluation and description of mitral abnormalities in HCM. Given significant practice variation, future studies could compare MV practice differences across institutions and how these impact long-term outcomes.

Pathoanatomic Findings and Treatment During Hypertrophic Obstructive Cardiomyopathy Surgery: The Role of Mitral Valve.

BACKGROUND: To assess the role of the mitral valve apparatus (leaflets, chordae and papillary muscles, (PM)) in left ventricle outflow tract (LVOT) obstruction, and results of the surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM). METHODS: Twenty-eight consecutive patients (58±11years, 53% female) undergoing HOCM surgery from 2007 to 2016 at our institute were retrospectively reviewed. Endpoints included the involvement of the mitral valve in LVOT obstruction, mortality, and changes in clinical and echocardiographic characteristics after HOCM surgery. RESULTS: Secondary chordae tendineae tractioning the anterior mitral leaflet to the interventricular septum, and systolic anterior motion were detected in 78% of the patients. Anomalous, hypertrophied, and fused PM with muscularis trabeculae hypertrophy were found in 50%, 25%, and 35% of the patients, respectively. Four patients had posterior leaflet redundancy. Secondary chordae (92%), PM, and muscularis trabeculae resection (71%), and PM splitting and elongation (28%) were added variably to septal myectomy (100%). Nine procedures (32%) on mitral valve leaflets were performed, involving six posterior and three anterior mitral leaflets. Long-term follow-up was 4±2.8years. There was no hospital mortality, and NYHA was reduced from 3±0.5 to 1±0.7 (p<0.0001), the LVOT gradient from 88±35 to 20±18mmHg (p<0.0001), mitral valve regurgitation from grade 3±1 to 1±0.7 (p<0.0001), and septum thickness from 18±3 to 14±2mm (p<0.0001). CONCLUSIONS: The mitral valve apparatus contributes with all its components variably to LVOT dynamic obstruction thus surgical correction in addition to extended myectomy is recommended to achieve the best outcome.

[Isolated transaortic mitral valve repair for left ventricular outflow tract obstruction]. / Izolirovannaia transaortal'naia plastika mitral'nogo klapana kak metod lecheniia obstruktsii vykhodnogo trakta levogo zheludochka.

Hypertrophic cardiomyopathy (HCM) is congenital heart disease with prevalence 1 per 500. There are still unclear issues regarding optimal surgical strategy despite more than 50-year research of this disease. It is presented case report of surgical treatment of patient with obstructive HCM by using of non-standard volume and method of intervention.

Hypertrophic Cardiomyopathy and Left Ventricular Outflow Tract Obstruction: Expecting the Unexpected.

Hypertrophic cardiomyopathy is an increasingly recognized clinical disease that carries perioperative risk. Patients may or may not carry a preoperative diagnosis, but provocable left ventricular outflow tract gradients place them at risk for hemodynamic compromise under surgical conditions. Early recognition of obstructive patterns and rapid management alterations in the face of instability are imperative for the treatment of these patients. This review focuses on the diagnostic criteria, risk factors, and management strategies for the perioperative hypertrophic cardiomyopathy patient. Finally, novel diagnostic modalities are discussed.

Transient left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve: A stunning cause.

Left ventricular outflow tract obstruction (LVOTO) and systolic anterior motion (SAM) of the mitral valve may have various etiologies, of which hypertrophic cardiomyopathy is the most common. More rarely, an acute coronary syndrome, myocardial stunning, and takotsubo cardiomyopathy may give rise to LVOTO and SAM. Here, we present a 70-year-old female patient with a non-ST-elevation acute coronary syndrome treated with percutaneous coronary intervention. Echocardiography the day after, because of dyspnea and hypotension, revealed apical akinesia, LVOTO, and SAM, which proved completely reversible after treatment with a ß-blocker and a 2-month follow-up period. It was concluded that postischemic apical stunning had caused LVOTO and SAM.