Unmasking obstruction in hypertrophic cardiomyopathy with postprandial resting and treadmill stress echocardiography.

BACKGROUND: Latent left ventricular outflow tract obstruction (LVOTO) is an important cause of symptoms in patients with hypertrophic cardiomyopathy (HCM) but can be challenging to provoke. OBJECTIVES AND METHODS: To examine the value of postprandial resting and stress echocardiography and utilization of invasive or enhanced drug therapies (surgical myectomy, alcohol septal ablation, disopyramide and mavacamten) in patients with postprandial LVOTO. Consecutive HCM patients without LVOTO underwent routine and postprandial echocardiography at rest, with provocation (Valsalva and standing) and after symptom-limited treadmill stress. RESULTS: Among 252 patients (mean age 58 years, 39% women), postprandial LVOT gradients were higher compared with routine echocardiography at rest (median 9.0 [0-38.0] vs 0 [0-14.0] mmHg, p<0.0001) and with provocation (18.5 [0-70.3] vs 1.5 [0-41.0] mmHg, p<0.0001). Postprandial exercise (PPXSE) gradients were higher in a subset of 44 patients who underwent both postprandial and fasting stress echocardiography, (47.0 [5.3-81.0] vs 17.5 [0-46.0] mmHg, p<0.0001). In total, 49 (19.5%) patients achieved the ≥50 mmHg threshold under routine conditions (rest/provocation); 90 (35.7%) additional patients achieved postprandial gradients ≥50 mmHg (rest/provocation/exercise), 38 (15.1%) with PPXSE alone. A total of 71 patients were treated with 91 invasive or enhanced drug therapies, 32 (45.1%) of whom had gradients ≥50 mmHg only after eating (rest/provocation) and 8 (11.3%) only with PPXSE, with symptom relief in the majority. CONCLUSIONS: Postprandial echocardiography was useful at unmasking LVOTO in more than one third of patients who did not have high gradients otherwise. Eating before echocardiography is a powerful provocative tool in the evaluation of patients with HCM.

Computer-Assisted Transcatheter Mitral Valve Implantation for Valve-in-Valve Procedures.

Transcatheter mitral valve-in-valve is an alternative to high-risk reoperation on a failing bioprosthesis. It entails specific challenges such as left ventricular outflow tract obstruction. We propose a patient-specific augmented imaging based on preoperative planning to assist the procedure. Valve-in-valve simulation was performed to represent the optimal level of implantation and the neo-left ventricular outflow tract. These data were combined with intraoperative images through a real-time 3D/2D registration tool. All data were collected retrospectively on one case (pre and per-procedure imaging). We present for the first time an intraoperative guidance tool in transcatheter mitral valve-in-valve procedure.

Transapical Approach to Septal Myectomy for Hypertrophic Cardiomyopathy.

A 63-year-old symptomatic female with apical hypertrophic cardiomyopathy and diastolic disfunction was admitted to the hospital. What is the best way to manage this patient? This study is a literature review that was performed to answer this question. The following PubMed search strategy was used: 'Hypertrophic obstructive cardiomyopathy' [All Fields] OR 'apical myectomy' [All Fields], NOT 'animal [mh]' NOT 'human [mh]' NOT 'comment [All Fields]' OR 'editorial [All Fields]' OR 'meta-analysis [All Fields]' OR 'practice-guideline [All Fields]' OR 'review [All Fields]' OR 'pediatrics [mh]'. The natural history of the disease has a benign prognosis; however, a watchful strategy was associated with the risk of adverse cardiovacular events. Contrastingly, transapical myectomy was associated with low surgical risk and acceptable outcomes. In our case, the patient underwent transapical myectomy with an unconventional post-operative period. Control echocardiography showed marked left ventricular (LV) cavity enlargement: LV end-diastolic volume, 74 mL; LV ejection fraction, 65%; and LV stroke volume index increased to 27 mL/m2. The patient was discharged 7 days after myectomy. At 6 months post-operation, the patient was NYHA Class I, with a 6 min walk test score of 420 m. Therefore, transapical myectomy may be considered as a feasible procedure in patients with apical hypertrophic cardiomyopathy and progressive heart failure.

Impact of VA-ECMO on Dynamic LV Outflow Obstruction After Transcatheter Aortic Valve Replacement.

Dynamic left ventricular outflow obstruction is a rare but severe complication of transcatheter aortic valve replacement. It presents as a paradoxical hemodynamic collapse after relieving the left ventricular afterload. Considering its unique pathophysiology, this entity dictates counterintuitive treatments. We describe a case of left ventricular outflow obstruction treated with venoarterial extracorporeal membrane oxygenation and discuss its management principles.

Cardiac Myosin Inhibitors: Expanding the Horizon for Hypertrophic Cardiomyopathy Management.

OBJECTIVE: To review the current literature on the efficacy and safety of cardiac myosin inhibitors (CMIs) for the treatment of hypertrophic cardiomyopathy (HCM). DATA SOURCES: A literature search was conducted on PubMed from origin to April 2023, using the search terms "MYK-461," "mavacamten," "CK-3773274," and "aficamten." Studies were limited to English-based literature, human subjects, and clinical trials resulting in the inclusion of 13 articles. ClinicalTrials.gov was also used with the same search terms for ongoing and completed trials. STUDY SELECTION AND DATA EXTRACTION: Only phase II and III studies were included in this review except for pharmacokinetic studies that were used to describe drug properties. DATA SYNTHESIS: CMIs enable cardiac muscle relaxation by decreasing the number of myosin heads that can bind to actin and form cross-bridges. Mavacamten, the first Food and Drug Administration (FDA)-approved drug in this class, has been shown to improve hemodynamic, functional, and quality of life measures in HCM with obstruction. In addition, aficamten is likely to become the next FDA-approved CMI with promising phase II data and an ongoing phase III trial expected to release results in the next year. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON WITH EXISTING DRUGS: CMIs provide a novel option for obstructive hypertrophic cardiomyopathy, particularly in those not suitable for septal reduction therapy. Utilization of these agents requires knowledge of drug interactions, dose titration schemes, and monitoring parameters for safety and efficacy. CONCLUSIONS: CMIs represent a new class of disease-specific drugs for treatment of HCM. Cost-effectiveness studies are needed to delineate the role of these agents in patient therapy.

Is There a Role for Alcohol Septal Ablation in Young Patients with Medically Refractory Hypertrophic Obstructive Cardiomyopathy?

Surgical myectomy is recommended for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) after optimal pharmacological therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) is reserved for high-risk adults. Symptomatic patients below 25 years underwent either surgery or PTSMA after heart-team discussion and informed consent. Echocardiography assessed gradients in surgical group. PTSMA group underwent invasive transseptal hemodynamic assessment, selective coronary angiography and super-selective cannulation of septal perforators using microcatheters. Contrast echocardiography through the microcatheter identified the myocardial target for PTSMA. Hemodynamic and electrocardiographic monitoring guided alcohol injection. Both groups were continued on beta-blockers. Symptoms, echocardiographic gradients and Brain natriuretic peptide (NTproBNP) measurements were assessed on follow-up. Twelve patients aged 5-23 years (11-98 kg) formed the study group. Indications for PTSMA in 8 patients included abnormal mitral valve anatomy warranting replacement (n = 3), Jehovah's witness (n = 2), severe neurodevelopmental and growth retardation (n = 1) and refusal of surgery (n = 2). PTSMA targeted first perforator (n = 5), second perforator (n = 2) and anomalous septal artery from left main trunk (n = 1). Outflow gradient reduced from 92.5 ± 19.7 to 33.1 ± 13.5 mmHg. At a median follow-up of 38 months (range 3-120 weeks), the peak instantaneous echocardiographic gradient was 32 ± 16.5 mmHg. Gradient reduced in four surgical patients from 86.5 ± 16.3 mmHg to 42 ± 14.7 mm Hg. All patients were in NYHA class I/II on follow-up. The mean NTproBNP in PTSMA group reduced from 6084 ± 3628 pg/ml to 3081 ± 2019 pg/ml; it was 1396 and 1795 pg/ml in surgery. PTSMA may be considered in medically refractory high-risk young patients. It relieves symptoms and reduces gradient. Though surgery is preferred in young patients, PTSMA may have a role in selected patients.

Sitting maneuver to uncover latent left ventricular outflow tract obstruction in patients without hypertrophic cardiomyopathy.

BACKGROUND: Left ventricular outflow tract obstruction [LVOTO; pressure gradient (PG) ≥30 mmHg] is observed in some patients without hypertrophic cardiomyopathy (HCM), and it may develop especially in older patients without HCM (non-HCM). The aim of this study is to investigate if the Valsalva or an upright sitting maneuver can unveil latent LVOTO in patients with non-HCM. METHODS: A total of 33 non-HCM patients with a late peaking or dagger-shaped pulsed Doppler waveform of the LVOT and PG <30 mmHg were included. The Doppler flow velocity of the LVOT was measured at rest, after the Valsalva and a sitting maneuver. Peak PG of ≥30 mmHg after either maneuver was defined as latent LVOTO. The angle between the left ventricular septum and the aorta in the parasternal long-axis view and the apical three-chamber view was measured. RESULTS: Twenty (61 %) of the 33 patients (mean age 74 ±â€¯9 years) were diagnosed with latent LVOTO. Of these, five (25 %) patients were diagnosed after both the Valsalva and sitting maneuver, and 15 (75 %) were diagnosed only after the sitting maneuver. The latent LVOTO group had a significantly smaller angle than the no-LVOTO group between the ventricular septum and the aorta in the parasternal long axis views (107 ±â€¯8° vs. 117 ±â€¯8°, p < 0.01). CONCLUSION: The sitting maneuver is better than the Valsalva maneuver in unveiling latent LVOTO in older, non-HCM patients.

Perioperative and Anesthetic Considerations in Shone's Complex.

Shone's complex is a congenital cardiac disease consisting of the following four lesions: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and aortic coarctation. Though not all components are required for a diagnosis, the end result is both left ventricular inflow and outflow obstruction, which typically present in patients as congestive heart failure. The complex pathology requires careful management and surgical decision-making to ensure an optimal outcome. This review will focus on the anatomy, physiology, and perioperative anesthetic management of patients with Shone's complex.

Computer-Assisted Transcatheter Mitral Valve Implantation for Valve-in-Valve Procedures

ABSTRACT Transcatheter mitral valve-in-valve is an alternative to high-risk reoperation on a failing bioprosthesis. It entails specific challenges such as left ventricular outflow tract obstruction. We propose a patient-specific augmented imaging based on preoperative planning to assist the procedure. Valve-in-valve simulation was performed to represent the optimal level of implantation and the neo-left ventricular outflow tract. These data were combined with intraoperative images through a real-time 3D/2D registration tool. All data were collected retrospectively on one case (pre and per-procedure imaging). We present for the first time an intraoperative guidance tool in transcatheter mitral valve-in-valve procedure.

Challenges of Management of Subaortic Membrane in a Young Adult Patient: A Case Report.

This article presents a case review and literature review focused on the challenges of managing subaortic membranes (SAMs) in young adult patients with mild aortic regurgitation (AR) or aortic stenosis (AS). The study aims to discuss the diagnosis of SAM, the imaging studies used for assessment, the management strategies in young patients, the risk of valvular damage, and the controversy surrounding prophylactic resection in mild AR. The management of SAM in adults poses challenges due to limited treatment options and potential complications, necessitating further investigation into the progression of AS and AR in asymptomatic SAM patients. The case presentation describes a 40-year-old male with muscular dystrophy who presented with symptoms and was diagnosed with SAM. Various imaging techniques, including CT chest, transthoracic echocardiogram (TTE), and transesophageal echocardiogram (TEE), were used to confirm the presence and severity of SAM. Based on the patient's clinical profile and the absence of surgical indications, medical therapy was initiated, and regular outpatient follow-up was recommended to monitor disease progression. The discussion highlights the challenges in diagnosing SAM, the importance of imaging studies, and the potential complications associated with SAM in young patients. The article also explores the management options for SAM, emphasizing surgical resection as the definitive treatment, while acknowledging the limited success rates of alternative approaches. Close monitoring and prompt intervention for complications are crucial in the management of SAM. The concluding statement emphasizes the need for further research to explore alternative treatments for SAM in young patients.

Accessory mitral valve tissue: a differential diagnosis of an obstructive mass on the left ventricular outflow tract.

Accessory mitral valve tissue is a rare congenital cardiac anomaly that is typically discovered incidentally during echocardiographic evaluation prompted by an asymptomatic murmur. This pathology has characteristic echocardiographic elements and is usually associated with other CHD. The decision to perform surgical resection depends on factors such as the degree of obstruction, presence of symptoms, presence of other CHDs, and risk of thrombosis. The researchers hereby present a case of an asymptomatic paediatric patient with accessory mitral valve tissue that produced left ventricular outflow tract obstruction.

Now You See Me Now You Don't: Subaortic Membrane Causing a Diagnostic Dilemma.

Subaortic stenosis secondary to subaortic membrane is the second most common form of left ventricular outflow tract obstruction. We present the case of a 70-year-old male patient who presented with a 6-week history of progressive signs of heart failure. Multimodality imaging was required to confirm the presence of a subaortic membrane. (Level of Difficulty: Beginner.).

Metoprolol or Verapamil in the Management of Patients With Hypertrophic Cardiomyopathy: A Systematic Review.

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease and is a prevalent cause of sudden cardiac death (SCD). This study aims to establish the benefits and therapeutic value metoprolol or verapamil offer to patients who suffer from symptoms caused by HCM, with regard to resolving left ventricular outflow tract obstruction (LVOTO), as well as improving a patient's quality of life and reducing symptoms. We conducted a systematic review to find clinical studies that described the use of metoprolol or verapamil in the management of HCM. Three databases were analyzed for studies, PubMed, Google Scholar, and ScienceDirect. We discovered 6,260 potentially eligible records across all the databases. According to our eligibility criteria, we included four studies in this review. Metoprolol showed median left ventricular outflow tract (LVOT) gradients of 25 mm Hg versus 72 mm Hg (P = 0.007) at rest, 28 mm Hg versus 62 mm Hg (P < 0.001) at peak exercise, and 45 mm Hg versus 115 mm Hg (P < 0.001) post-exercise. Verapamil also showed a statistically significant increase in exercise capacity. Both drugs have been shown to be safe to use with a good side effect profile; however, metoprolol was better tolerated in the patient population that was tested in the studies collected. In this study, metoprolol was effective in reducing LVOT and improving the quality of life in patients, while verapamil showed variable effects on both exercise capacity and baseline hemodynamics.

Unusual Fungal Endocarditis Causing Disseminated Infection After Renal Transplant.

Fungal endocarditis is a relatively uncommon disease; it mostly affects those with intracardiac devices and those with compromised immune systems. Scedosporium apiospermum (S. apiospermum), the asexual state of Pseudoallescheria boydii, has become increasingly reported as an opportunistic pathogen. These filamentous fungi present in soil, sewage, and polluted waters, and was previously recognized to cause human infection after their inhalation or traumatic subcutaneous implantation. In immunocompetent individuals, it usually causes localized diseases depending on the site of entry such as skin mycetoma. However, in immunocompromised hosts, the fungus species appear to disseminate and cause invasive infections, frequently reported to be life-threatening with poor response to antifungal medications. S. apiospermum invasive endocarditis remains a rare complication, mostly cited in immunocompetent hosts with prosthetic cardiac valves or other intracardiac devices and severely immunocompromised patients with hematologic neoplasia. Herein, we describe the case of a renal transplant patient on immunosuppressive medications who presented with S. apiospermum fungal septic infection that invaded the left ventricular outflow tract (LVOT) causing endocarditis with disseminated infection and resulted in poor clinical outcome.

Computed Tomographic Evaluation of Congenital Left Ventricular Outflow Obstruction.

Congenital left ventricular outflow obstruction represents a multilevel obstruction with several morphological forms. It can involve the subvalvular, valvar, or supravalvular portion of the aortic valve complex, and may coexist. Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital LVOT obstruction. Unlike transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging, it is not bounded by a small acoustic window, needs for anaesthesia or sedation, and metallic devices. Current generations of CT scanners with excellent spatial and temporal resolution, high pitch scanning, wide detector system, dose reduction algorithms, and advanced 3-dimensional postprocessing techniques provide a high-quality alternative to CMR or diagnostic cardiac catheterization. Radiologists performing CT in young children should be familiar with the advantages and disadvantages of CT and with the typical morphological imaging features of congenital left ventricular outflow obstruction.

TGA + IVS + LVOTO: patterns of practice and outcomes.

PURPOSE: Transposition of great arteries with intact ventricular septum and left ventricular outflow tract obstruction (TGA + IVS + LVOTO) is uncommon. We reviewed operations performed in patients with TGA + IVS + LVOTO in the European Congenital Heart Surgeons Association Congenital Database (ECHSA-CD). METHODS: All 109 patients with a diagnosis of TGA + IVS + LVOTO in ECHSA-CD who underwent cardiac surgery during a 21-year period (01/2000-02/2021, inclusive) were included. Preoperative variables, operative data, and postoperative outcomes were collected. RESULTS: These 109 patients underwent 176 operations, including 37 (21.0%) arterial switch operations (ASO), 26 (14.2%) modified Blalock-Taussig-Thomas shunts (MBTTS), 11 (6.2%) Rastelli operations, and 13 (7.3%) other palliative operations (8 superior cavopulmonary anastomosis[es], 4 Fontan, and 1 other palliative procedure). Of 37 patients undergoing ASO, 22 had a concomitant procedure.There were 68 (38.6%) reoperations, including 11 pacemaker procedures and 8 conduit operations. After a systemic-to-pulmonary artery shunt, reoperations included shunt reoperation (n = 4), Rastelli (n = 4), and superior cavopulmonary anastomosis (n = 3).Overall Operative Mortality was 8.2% (9 deaths), including three following ASO, two following "Nikaidoh, Kawashima, or LV-PA conduit" procedures, and two following Rastelli. Postoperative complications occurred after 36 operations (20.4%). The most common complications were delayed sternal closure (n = 11), postoperative respiratory insufficiency requiring mechanical ventilation >7 days (n = 9), and renal failure requiring temporary dialysis (n = 8). CONCLUSION: TGA + IVS + LVOTO is rare (109 patients in ECHSA-CD over 21 years). ASO, MBTTS, and Rastelli are the most common operations performed for TGA + IVS + LVOTO. Larger international studies with long-term follow-up are needed to better define the anatomy of the LVOTO and to determine the optimal surgical strategy.

Annular Rupture Due to Calcified Nodule Located in Left Ventricular Outflow Tract (LVOT) During Transcatheter Aortic Valve Replacement (TAVR) Managed by Protamine Sulfate.

Annular rupture is a rare yet fatal complication of transcatheter aortic valve replacement (TAVR). The likelihood of annular rupture is increased by the presence of extensive subannular calcification, excessive balloon dilatation for valve expansion or aggressive valve oversizing to prevent paravalvular leakage during TAVR. Although extensive annular or aortic root calcification increases the likelihood of annular rupture, rupture due to the presence of a calcified nodule in the left ventricular outflow tract (LVOT) is not commonly reported. We present the case of an 84-year-old man who developed an annular rupture during TAVR, likely due to the presence of a calcified nodule located in LVOT, which was noted on a pre-procedural computed tomography (CT) scan. The rupture was identified early and was successfully reversed with the administration of protamine sulfate during the procedure.