UNASSIGNED: Although Takotsubo syndrome (TTS) is generally considered a benign disease, recent reports showed the incidence of cardiogenic shock due to left ventricular outflow tract obstruction (LVOTO), mitral regurgitation (MR), and primary pump failure was estimated to be 6-20%.
UNASSIGNED: A 78-year-old woman presented with chest pain and cold sweats 2 days after surgery for lung cancer. Acute coronary syndrome was suspected based on her symptoms, electrocardiography, transthoracic echocardiography (TTE), and laboratory data; thus, emergency catheterization was performed. Normal coronaries were observed, with hyperkinesis at the base of the left ventricle and akinesis at its apex, leading to the diagnosis of the apical ballooning type of TTS. Pressure differences between the apex of the left ventricle (168/8/28 mmHg) and aorta (94/50/64 mmHg) indicated the presence of LVOTO. Two days after TTS onset, she developed cardiogenic shock (blood pressure was 54/38 mmHg). Transthoracic echocardiography showed acute MR due to systolic anterior motion of the mitral valve caused by LVOTO, which was further exacerbated by paroxysmal atrial fibrillation. Fluid resuscitation, intravenous β-blockers, and amiodarone were administered for reduction of the pressure gradient in the left ventricular outflow, rate control, and sinus rhythm maintenance. Her condition improved along with the MR, thereby improving LVOTO and maintaining sinus rhythm.
UNASSIGNED: Takotsubo syndrome should be kept in mind as a potential cause of acute MR due to LVOTO. Catheterization and multiple follow-up TTE play a major role in early detection for this condition.

OBJECTIVE: In clinical trials, mavacamten reduced left ventricular outflow tract obstruction (LVOTO) and improved symptoms in patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). We aimed to share our real-world experience with the efficacy and safety of mavacamten in this patient population.
RESULTS: This retrospective, single-centre study included patients with symptomatic oHCM from March 2023 to November 2023. Inclusion criteria were oHCM, age >18 years, significant LVOTO (gradient >50 mmHg at rest or with Valsalva), New York Heart Association (NYHA) class ≥II despite maximally tolerated medical therapy, and left ventricular ejection fraction (LVEF) >55%. Patients were evaluated by echocardiography, NYHA class, electrocardiography and Holter monitor on each monthly visit for 3 months. A total of 31 patients were included in this study. The mean (SD) age was 58 (16.5) years, and 14 (45%) were female. Mean provoked left ventricular outflow tract gradient (LVOTG) reduced by -49.4 mmHg (P < 0.001) at 4 weeks, -59.2 mmHg (P < 0.001) at 8 weeks, and -60.8 mmHg (P < 0.001) at 12 weeks. Twenty-six of the 31 patients (83.8%) achieved an LVOTG ≤30 mmHg at Week 12. No major side effects were reported. Sixty-seven percent experienced ≥2 NYHA class improvements, LVEF remained above 55% and no dose titration was made.
CONCLUSIONS: Our real-world experience aligns with established mavacamten trial outcomes. Continuous vigilance and longitudinal investigations are needed to further assess potential long-term impacts.

暂无摘要。

UNASSIGNED: We report endocardial radiofrequency (RF) ablation as an alternative treatment approach for a symptomatic patient with obstructive hypertrophic cardiomyopathy (oHCM), who is not suitable for surgical septal myectomy or alcohol septal ablation. Endocardial RF ablation, with detailed 3D mapping of the intrinsic conducting system, offers the possibility of reducing the risk of complete heart block rates and of effectively relieving symptoms.
UNASSIGNED: We present a symptomatic 51-year-old female patient with oHCM and a maximum left ventricular outflow tract (LVOT) gradient of 148 mmHg. Because of alcohol septal ablation failure, endocardial RF ablation in combination with detailed mapping of the intrinsic conduction system and intraprocedural imaging was performed. The 6-month follow-up showed a significant improvement in exercise tolerance, no relevant dynamic LVOT obstruction with a gradient of 22 mmHg under Valsalva.
UNASSIGNED: In the current case report, endocardial RF ablation persistently reduced LVOT gradients in a patient with oHCM. Pre-interventional imaging, detailed 3D mapping of the conduction system, and correlation to intracardiac and transthoracic echocardiography were key for an effective and safe ablation of a small target zone.

In this issue of Structural Heart, high-impact presentations from Transcatheter Valve Therapies 2023 are reviewed. Dr Jaffar Khan provided updates on the current understanding of left ventricular outflow tract obstruction in the field of transcatheter mitral valve replacement, highlighting known predictors of obstruction, a generally agreed-upon strategy for preprocedure assessment, and a host of management strategies in various stages of development and study.

Despite considerable interest in the syndrome of acute left ventricular (LV) ballooning, its pathophysiology has remained ill-defined. In this review, we explore observational data describing two etiologies of acute LV ballooning: neurohumoral classic Takotsubo Syndrome (TTS), and acute severe unrelenting left ventricular outflow tract (LVOT) obstruction in patients with obstructive hypertrophic cardiomyopathy (HCM). We describe the clinical presentation and varying pathophysiology of these presentations, explore how echocardiography and cardiac catheterization may help differentiate between the two etiologies, and detail differences in management. We highlight the significant overlap as well as key differentiating features of these conditions, with the aim to improve diagnostic awareness and accuracy and appropriately tailor therapy.

The intricate interplay between mitral regurgitation (MR) and left ventricular outflow tract (LVOT) obstruction may result in two clinical scenarios: prosthesis-related LVOT obstruction after mitral valve replacement (TMVR) and systolic anterior motion (SAM)-associated MR. This review provides a comprehensive overview of the pathophysiology, risk assessment, and transcatheter interventions for mitigating the likelihood of LVOT obstruction in patients undergoing TMVR. In addition, it extends its focus to SAM-associated MR, elucidating the different aetiological mechanisms contributing to this phenomenon, beyond hypertrophic cardiomyopathy. Transcatheter treatment options, are explored as potential therapeutic strategies, offering insights into their hemodynamic effectiveness and limitations.

Obstructive hypertrophic cardiomyopathy (obstructive HCM) is a hereditary disease characterized by septal hypertrophy and dynamic left ventricular outflow tract (LVOT) obstruction. Other than septal hypertrophy, mitral valve abnormalities are also quite common in patients with obstructive HCM, which may contribute to systolic anterior motion (SAM) of the mitral valve and LVOT obstruction. Surgical myectomy is the standard treatment to achieve anatomic correction of obstructive HCM, but controversies remain on whether and how the mitral valve procedures should be performed at the same time. In this review, we first described the mitral valve abnormalities in patients with obstructive HCM and their surgical corrections, we then explained the controversies based on current clinical studies, and we finally made a brief introduction on our surgical strategy and results.

BACKGROUND: New postprocessing software facilitates 3-dimensional (3D) echocardiographic determination of mitral annular (MA) and neo-left ventricular outflow tract (neo-LVOT) dimensions in patients undergoing transcatheter mitral valve replacement (TMVR).
OBJECTIVE: This study aims to test the accuracy of 3D echocardiographic analysis as compared to baseline computed tomography (CT).
METHODS: A total of 105 consecutive patients who underwent TMVR at 2 tertiary care centers between October 2017 and May 2023 were retrospectively included. A virtual valve was projected in both baseline CT and 3D transesophageal echocardiography (TEE) using dedicated software. MA dimensions were measured in baseline images and neo-LVOT dimensions were measured in baseline and postprocedural images. All measurements were compared to baseline CT as a reference. The predicted neo-LVOT area was correlated with postprocedural peak LVOT gradients.
RESULTS: There was no significant bias in baseline neo-LVOT prediction between both imaging modalities. TEE significantly underestimated MA area, perimeter, and medial-lateral dimension compared to CT. Both modalities significantly underestimated the actual neo-LVOT area (mean bias pre/post TEE: 25.6 mm2, limit of agreement: -92.2 mm2 to 143.3 mm2; P < 0.001; mean bias pre/post CT: 28.3 mm2, limit of agreement: -65.8 mm2 to 122.4 mm2; P = 0.046), driven by neo-LVOT underestimation in the group treated with dedicated mitral valve bioprosthesis. Both CT- and TEE-predicted-neo-LVOT areas exhibited an inverse correlation with postprocedural LVOT gradients (r2 = 0.481; P < 0.001 for TEE and r2 = 0.401; P < 0.001 for CT).
CONCLUSIONS: TEE-derived analysis provides comparable results with CT-derived metrics in predicting the neo-LVOT area and peak gradient after TMVR.

UNASSIGNED: Aortic stenosis (AS) in combination with left ventricular outflow tract obstruction (LVOTO) has occasionally been reported. However, making a precise diagnosis and successfully treating this combination is challenging due to the hemodynamic interaction between the two conditions.
UNASSIGNED: A 56-year-old male patient who had been diagnosed with severe AS and asymmetric left ventricular hypertrophy underwent aortic valve replacement (AVR) and a conventional septal myectomy. Immediately after the procedure, significant systolic anterior motion and mitral regurgitation developed, necessitating a surgical mitral edge-to-edge repair. Ten days after the procedure, the patient developed hematuria and LVOTO, which was confirmed by echocardiography. Because the LVOTO might have been the cause of the hematuria, the patient underwent alcohol septal ablation, but this had little effect. Three months later, a transapical beating-heart septal myectomy (TA-BSM) was performed in our hospital. Postoperatively, the LVOTO had been significantly ameliorated and the hematuria had resolved.
UNASSIGNED: For patients with AS and LVOTO due to a hypertrophic interventricular septum, inadequate amelioration of the LVOTO after AVR may lead to severe hemolytic hematuria. TA-BSM is a minimally invasive, safe, and effective surgical procedure for ameliorating LVOTO in patients with aortic valve prostheses.