Transapical beating-heart septal myectomy for hypertrophic cardiomyopathy patients with midventricular obstruction.

Background: We developed a novel minimally invasive transapical beating-heart septal myectomy (TA-BSM) procedure for patients with midventricular obstruction (MVO), without the aid of cardiopulmonary bypass. This study aims to describe the TA-BSM procedure for the relief of MVO and to detail the clinical outcomes in these patients. Methods: Sixty-one patients receiving TA-BSM for MVO were included: isolated MVO (n = 12) and combined MVO and subaortic obstruction (n = 49). We reviewed the electronic medical record to collect information on preoperative, intraoperative, and postoperative parameters. Results: The intraventricular pressure gradient after the resection was largely attenuated. On the catheter measurement, the median resting and provoked gradient decreased by 29.0 and 71.0 mm Hg, respectively. Likewise, the resting intraventricular gradient was successfully reduced from 58.0 to 11.0 mm Hg, and the maximal intraventricular gradient was reduced from 88.0 to 20.0 mm Hg at 6 months follow-up. In addition, all patients showed significantly improved MR and 37 of 42 patients with preoperative MR grade ≥2+ showed MR grade ≤1+ after TA-BSM. During the follow-up, no death was observed and no one had HCM-related rehospitalization. All patients reported improvement in symptoms and the mean New York Heart Association class improved from 3.0 (IQR, 3.0-3.0) preoperatively to 1.0 (IQR, 1.0-1.0) at 6 months follow-up. Conclusions: The TA-BSM procedure is a valuable therapy to relieve MVO, improving hemodynamics and providing satisfactory clinical outcomes. The procedure can also preserve favorable outcomes for patients with MVO and concomitant subaortic obstruction.

Efficacy and safety of a transaortic approach to midventricular and apical septal myectomy.

OBJECTIVE: The study objective was to evaluate the safety and efficacy of a transaortic approach to midventricular and apical septal myectomy in patients with hypertrophic cardiomyopathy with left ventricular outflow tract or midventricular obstruction. METHODS: From January 2018 to August 2023, 940 patients underwent transaortic septal myectomy at the Cleveland Clinic, of whom 682 (73%) had midventricular or apical resection. Patients who underwent isolated basal myectomies were excluded. Templated operative reports designated septal regions resected as basal (opposition to mitral valve up to the leaflet tips), midventricular (leaflet tips to just beyond the papillary muscle heads), and apical (apical third of the ventricle). Myocardial resection specimen weights, intraventricular gradients, and clinical outcomes were assessed. RESULTS: Of the 682 patients, 582 (85%) had basal plus midventricular resection and 78 (11%) had basal, midventricular, and apical resection. Mean preoperative intraventricular gradient was 102 ± 41 mm Hg. Median resection weight was 10 g (15th, 85th percentiles: 7, 15), and mean postoperative intraventricular gradient was 16 ± 10 mm Hg, with 625 (96%) patients achieving gradients 36 mm Hg or less. There were no iatrogenic mitral or aortic valve injuries. Permanent pacemaker placement was required in 38 patients (5.6%), of whom 8 (1.2%) had normal preoperative conduction. Operative mortality occurred in 1 patient (0.1%) after an intraoperative ventricular septal defect. CONCLUSIONS: Most patients undergoing septal myectomy for relief of obstruction required resection beyond the basal septum. With specialized instrumentation, detailed imaging and knowledge of variable septal anatomy, resecting midventricular and apical septal muscle can be safely and effectively achieved through a transaortic approach.

Apical hypertrophic cardiomyopathy: pathophysiology, diagnosis and management.

Since the first description of apical hypertrophic cardiomyopathy (ApHCM) in 1976, contrasting information from all over the world has emerged regarding the natural history of the disease. However, the recommended guidelines on hypertrophic cardiomyopathy (HCM) pay a cursory reference to ApHCM, without ApHCM-specific recommendations to guide the diagnosis and management. In addition, cardiologists may not be aware of certain aspects that are specific to this disease subtype, and a robust understanding of specific disease features can facilitate recognition and timely diagnosis. Therefore, the review covers the incidence, pathogenesis, and characteristics of ApHCM and imaging methods. Echocardiography and cardiovascular magnetic resonance imaging (CMR) are the most commonly used imaging methods. Moreover, this review presents the management strategies of this heterogeneous clinical entity. In this review, we introduce a novel transapical beating-heart septal myectomy procedure for ApHCM patients with a promising short-time result.

Transapical approach under 3D printing guidance for myectomy in apical hypertrophic cardiomyopathy: A case report / 中国胸心血管外科临床杂志

@#We reported a 26-year-old male who was diagnosed with apical hypertrophic cardiomyopathy with left ventricular aneurysm. The location of the hypertrophic myocardium and the extent of resection were accurately assessed preoperatively using 3D modeling and printing technology. Myectomy was performed via transapical approach, and the intraoperative exploration was consistent with the description of the preoperative 3D modeling. The patient underwent the surgery successfully without any complications during the hospitalization, and the cardiopulmonary bypass time was 117 min, the aortic cross-clamping time was 57 min, and the hospital stay time was 7 d. The postoperative echocardiography demonstrated left ventricular cavity flow patency. This case provides a reference for the management of patients with apical hypertrophic cardiomyopathy.

A case of hypertrophic cardiomyopathy with right ventricular outflow tract and left midventricular obstruction.

We describe a case of a 59-year-old woman with hypertrophic cardiomyopathy who remained with right ventricular outflow tract obstruction after the pressure gradient in the left midventricle was resolved by a drug with a negative inotropic effect. The patient was diagnosed with hypertrophic cardiomyopathy 30 years previously and was only on low-dose beta-blocker therapy. She presented at our hospital with suspected exacerbation of heart failure because of the development and exacerbation of dyspnea and chest tightness. Transthoracic echocardiography showed an accelerated blood flow of 3 m/s in the middle of the left ventricle; thus, she was started on cibenzoline, a drug with a negative inotropic effect. After admission, intracardiac pressure measurement showed no pressure gradient in the left chamber. However, there was a pressure gradient of 18 mmHg between the apex of the right ventricle and the right ventricular outflow tract, and right ventricular outflow tract obstruction was confirmed on cardiac magnetic resonance imaging. We decided to reinforce the negative inotropic effect by adding bisoprolol, and the subjective symptoms and auscultatory systolic murmur were eliminated 2 months later. Learning objective: Hypertrophy of the right ventricular myocardium can occur in patients with hypertrophic cardiomyopathy (HCM). However, right ventricular outflow tract obstruction remains a rare finding in patients with HCM, despite the presence of morphological abnormalities such as right ventricular hypertrophy. In patients with HCM, obstruction of the right ventricle should be considered if the symptoms and auscultatory findings do not match the left ventricular imaging findings.

Numerical Simulation Study on the Mechanism of Formation of Apical Aneurysm in Hypertrophic Cardiomyopathy With Midventricular Obstruction.

Apical aneurysm was observed to be associated with midventricular obstruction (MVO) in hypertrophic cardiomyopathy (HCM). To investigate the genesis of the apical aneurysm, the idealized numerical left ventricular models (finite-element left ventricle models) of the healthy left ventricle, subaortic obstruction, and midventricular obstruction in HCM of left ventricle were created. The mechanical effects in the formation of apical aneurysm were determined by comparing the myofiber stress on the apical wall between these three models (healthy, subaortic obstruction, and midventricular obstruction models). In comparing the subaortic obstruction model and MVO model with HCM, it was found that, at the time of maximum pressure, the maximum value of myofiber stress in MVO model was 75.0% higher than that in the subaortic obstruction model (654.5 kPa vs. 373.9 kPa). The maximum stress on the apex of LV increased 79.9, 69.3, 117.8% than that on the myocardium around the apex in healthy model, subaortic obstruction model, and MVO model, respectively. Our results indicated that high myofiber stress on the apical wall might initiate the formation process of the apical aneurysm.

A Case Report on Diagnostic Approach of a Complex Clinical Scenario: Differentiation Between Coronary Artery Disease and Apical Hypertrophic Cardiomyopathy as a Cause of Recurrent Debilitating Angina.

Apical hypertrophic cardiomyopathy (ApHCM) is a clinical challenge when presenting with symptoms of angina plus shortness of breath. An appropriate diagnosis of concurrent coronary artery disease (CAD) is needed for proper diagnosis, risk stratification, and management. We present a case of a 64-year-old gentleman with a history of ApHCM and CAD with previous percutaneous intervention presenting with recurrent angina. A repeat coronary angiography showed no new obstructive lesions. A stress cardiac magnetic resonance imaging was performed, which showed perfusion defect in the apex with apical scarring likely secondary to microvascular disease. The patient was managed medically with the improvement of symptoms. Diagnosis and management of CAD in patients with ApHCM are challenging. Multiple diagnostic modalities may be required for delineating the underlying pathology. Patients should be managed initially with medications. If symptoms are not controlled with medical management, a heart team approach with referral to an advanced center experienced in apical myectomy should be considered.

Left ventricular aneurysms in hypertrophic cardiomyopathy with midventricular obstruction: A systematic review of literature.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) with or without left ventricular apical aneurysm (LVA) had been studied in the past. Midventricular obstruction associated with HCM and LVA is a unique entity that has not been distinguished previously as a separate phenotypic disease in HCM patients. METHODS: A systematic review of Pubmed and Google Scholar was conducted from inception until September 2017 for all observational studies conducted on HCM with midventricular obstruction and LVA. RESULTS: A total of 94 patients from 39 studies were included in our analysis. The mean age of the patients was 58.05 ± 11.76 years with 59.6% being males. The most common electrocardiographic finding was T wave inversion occurring in 13.8% of the cases followed by ST elevation (9.5%). Maximal left ventricle (LV) wall thickness was reported 18.89 ± 5.19 mm on transthoracic echocardiography and paradoxical jet flow was detected in 29.8% of patients. Beta-blockers (58.5%) were the most common drug therapy at baseline and amiodarone (10.6%) was the most common antiarrhythmic used for ventricular tachycardia (VT). The most common complication, VT, occurred in 39.3% of cases and the incidence of all-cause mortality was 13.8 % over 16 ± 20.1 months follow-up. Implantable cardioverter defibrillator (ICD) was used in 37.2% of patients; 25.7% of patients with ICD received appropriate shock therapy. CONCLUSION: HCM with LVA and midventricular obstruction is a unique entity that appears to be associated with high incidence of morbidity and mortality. Thus, early diagnosis and therapeutic intervention is recommended for management of this condition.

[Effectiveness of Extended Myectomy in Patients With Hypertrophic Cardiomyopathy With Midventricular Obstruction].

PURPOSE: to assess effectiveness and safety of extended myectomy performed in patients with hypertrophic obstructive cardiomyopathy (HOCM) with midventricular obstruction. MATERIAL AND METHODS: Between 2010 and 2013 185 HOCM patients were operated for left ventricular outflow tract (LVOT) obstruction. Among these patients 32 had midventricular obstruction. Their age was 22-74 (mean 51.9+/-14.2) years. Mean peak gradient across LVOT was 89.1+/-20.4 mm Hg, thickness of interventricular septum was 26.9+/-4.3 mm. Operations were guided by intraoperative transesophageal echocardiography (TEE). RESULTS: There were no early deaths. Gradient at LVOT according to TEE decreased to 15.4+/-5.7 mm Hg. There were no complications specific for extended myectomy (such as ventricular septal defect, left ventricular wall rupture, or aortic regurgitation). In 2 (6.9%) patients permanent pacemaker was implanted because of complete atrio-ventricular block. Mean follow-up was 18.7 (95% confidence interval [CI] 17.2 to 20.3) months. Kaplan-Meier estimate of survival was 100% at 12 and 94.2% (95% CI 65.8-99.1%) at 22 months. CONCLUSION: Extended myectomy can be safely and effectively performed in HOCM patients with midventricular obstruction and should be considered individually in each patient.

Abnormalities of the Mitral Apparatus in Hypertrophic Cardiomyopathy: Echocardiographic, Pathophysiologic, and Surgical Insights.

Hypertrophic cardiomyopathy is a genetic disorder characterized by increased cardiac muscle mass. This disorder has broad phenotypic expression, including, among others, asymmetric septal hypertrophy, midcavity hypertrophy, and apical hypertrophy. In recent years, it has been recognized that hypertrophic cardiomyopathy is not characterized solely by ventricular hypertrophy but that a number of abnormalities of the mitral apparatus (papillary muscles, leaflets, chords, and annulus) may also occur. These figure prominently in the echocardiographic evaluation and surgical planning of patients with hypertrophic cardiomyopathy and serve as the focus of this review.

Implantable cardioverter defibrillator therapy and sudden death risk stratification in hypertrophic cardiomyopathy patients with midventricular obstruction: A single-center experience.

BACKGROUND: Previous studies reported that the presence of midventricular obstruction (MVO) was an independent determinant of sudden death and potentially lethal arrhythmic events in patients with hypertrophic cardiomyopathy (HCM). However, it remains unclear whether implantable cardioverter defibrillator (ICD) improves survival in HCM patients with MVO. In addition, the risk factors for lethal arrhythmic events in MVO-HCM patients are not fully understood. The aim of this study was to provide an overview of the ICD therapy on sudden death prevention, and to determine the risk factors for lethal arrhythmic events in MVO-HCM patients. METHODS: This study included 593 HCM patients. Left ventricular MVO was diagnosed when the peak midventricular gradient was estimated as ≥30mmHg. RESULTS: MVO was identified in 56 patients (9.4%), and 15 of the 56 MVO-HCM patients (26.8%) received an ICD. Six of 15 ICD-implanted patients (40.0%) had appropriate ICD interventions over the follow-up period of 6.5±5.1years after ICD implantation. Although two of 42 patients without an ICD died suddenly, no patients experienced sudden death after ICD implantation in patients with an ICD throughout the follow-up period of 9.0±8.0years after referral to our hospital. By multivariate analysis, maximal wall thickness was an independent determinant of lethal arrhythmic events in MVO-HCM patients. CONCLUSIONS: A quarter of MVO-HCM patients received an ICD, and the incidence of appropriate ICD intervention was about 6.2%/year. It may be necessary to give careful consideration to the prevention of lethal arrhythmic events in MVO-HCM patients, especially those with severe left ventricular hypertrophy.

"Ballooning" patterns in takotsubo cardiomyopathy reflect different clinical backgrounds and outcomes: a BOREAS-TCM study.

Whether different patterns of ventricular ballooning in takotsubo cardiomyopathy (TCM) reflect differences in trigger mechanisms or clinical outcomes is unclear. Here we examined differences in the clinical characteristics of typical and atypical forms of TCM. TCM patients (n = 251) in the BOREAS Registry were enrolled for comparison of TCM with apical ballooning (type A, n = 217) and TCM with non-apical ballooning (type non-A, n = 34). The percentage of females was significantly lower in the type non-A group (58.8 vs. 75.6 %), while other demographic parameters and triggers of TCM were similar in the two groups. Rate of mid-ventricular obstruction (MVO) was lower (2.9 vs. 14.3 %) in the type non-A group than in the type A group, though left ventricular ejection fractions in the two groups were comparable. During a follow-up period of 2.6 ± 2.8 years, TCM recurred in 2.9 % of the patients and cardiac death occurred in 4.0 %. Cox proportional hazard analysis indicated that body mass index (hazard ratio [HR]: 0.75, 95 % confidence interval [CI] 0.54-0.99) and MVO (HR: 14.71, CI 1.87-304.66) were determinants of TCM recurrence and that advanced age (HR: 1.09, CI 1.02-1.17) and cardiogenic shock (HR: 4.27, CI 1.07-18.93) were significantly associated with cardiac death. In conclusion, approximately 20 % of TCM patients show non-apical left ventricular ballooning, and female sex and MVO are less frequent in this type than in apical ballooning type TCM. Low body mass index and MVO are risk factors of recurrence, and advanced age and cardiogenic shock are risk factors of cardiac death in TCM.

Severe Midventricular Hypertrophic Obstructive Cardiomyopathy and Apical Aneurysm.

A 40-year-old man was found to have hypertrophic cardiomyopathy (HCM) with severe mid ventricular obstruction. The obstruction produced two distinct left ventricular chambers with an estimated 60 mmHg continuous wave (CW) Doppler intraventricular gradient. Pulsed wave (PW) Doppler showed high velocity systodiastolic flow from apex to base and flow from base to apex confined mostly to the second half of diastole. Cardiac magnetic resonance (CMR) showed midventricular obstruction, due to septal, parietal, and to an hypertrophic, double posteromedial papillary muscle; an apical aneurysm was detected. Aneurysm is underdiagnosed by echocardiography in HCM and an accurate anatomic definition is needed if surgery is planned; thus, a CMR should always be obtained in these patients.

4 Cases of Midventricular Obstructive Hypertrophic Obstructive Cardiomyopathy

In hypertrophic cardiomyopathy, the distribution and extent of left ventricular hypertrophy is known to be variable. Among the subtypes of hypertrophic cardiomyopathy, midventricular obstruction is a rare variant of obstructive hypertrophic cardiomyopathy. This variant is at higher risk of apical wall motion abnormality and/or infarction. We report 4 patients with midventricular obstructive hypertrophic cardiomyopathy who presented with chest pain. Significant systolic pressure gradients between basal and apical chamber of left ventricle were documented by cardiac catheterization and Doppler echocardiography in all patients, and left ventricular apical infarction was noted in one of them. During mean follow-up period of 32 months(21 months to 5 years), one patient with apical infarction died of malignant ventricular arrhythmia.

4 Cases of Midventricular Obstructive Hypertrophic Obstructive Cardiomyopathy

In hypertrophic cardiomyopathy, the distribution and extent of left ventricular hypertrophy is known to be variable. Among the subtypes of hypertrophic cardiomyopathy, midventricular obstruction is a rare variant of obstructive hypertrophic cardiomyopathy. This variant is at higher risk of apical wall motion abnormality and/or infarction. We report 4 patients with midventricular obstructive hypertrophic cardiomyopathy who presented with chest pain. Significant systolic pressure gradients between basal and apical chamber of left ventricle were documented by cardiac catheterization and Doppler echocardiography in all patients, and left ventricular apical infarction was noted in one of them. During mean follow-up period of 32 months(21 months to 5 years), one patient with apical infarction died of malignant ventricular arrhythmia.