Tailored Planning of Surgical Myectomy in Obstructive Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a genetic myocardial disease characterized by abnormal thickening of the myocardium caused by myocardial disarray and interstitial fibrosis. HCM is associated with sudden cardiac-related events, such as ventricular fibrillation, tachycardia, and syncope. Moreover, left ventricular or midcavity obstruction due to the thickened myocardium can result in severe heart failure and mortality in patients with HCM. Surgical myectomy is a standard treatment option for patients with symptomatic obstructive HCM; however, it is a complex procedure that requires careful planning and execution to avoid complications, such as residual flow obstruction, persistent obliteration of the left ventricular cavity in systole, or iatrogenic ventricular septal defects. Therefore, a thorough understanding of the mechanics of HCM and precise evaluation of the location and extent of the hypertrophic myocardium to be removed are crucial for preoperative planning. Multiphase cardiac CT postprocessing is important for preoperative evaluation and planning of surgical myectomy in patients with HCM. In this review, the authors highlight use of multiphase cardiac CT with step-by-step postprocessing methods to simulate successful surgical myectomy. The transaortic surgeon's view on end-diastolic phase images accurately represents the surgical field. Moreover, myocardial segmentation can be used to generate volume-rendered images and three-dimensional printing. CT evaluation can also assist in identifying concurrent abnormalities, such as mitral valve or papillary muscle abnormalities. In addition to CT, other imaging modalities for preoperative evaluation of HCM and postmyectomy evaluation methods are presented. ©RSNA, 2023 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Bilateral septal pacing in combination with coronary venous pacing for cardiac resynchronization therapy.

BACKGROUND: Conventional right ventricular pacing combined with coronary venous pacing (CVP) is a mainstay for cardiac resynchronization therapy (CRT). However, QRS duration of conventional CRT may be frequently more than 130 ms. This study aimed to evaluate the effectiveness of QRS narrowing by bilateral septal pacing (BSP) in combination with CVP for CRT (BSP-CRT). METHODS: Fourteen patients with QRS > 130 ms of conventional CRT after failure of physiological conduction system pacing were enrolled. Electrophysiologic characteristics were compared among different modes of CRT during procedure. BSP which was defined as capture of both sides of interventricular septum manifested as shortened R wave peak time without a right bundle branch block QRS pattern. RESULTS: BSP-CRT were successfully achieved in 85.7% (12/14) patients. QRS duration at baseline was 185 ± 13 ms and significantly narrowed to 156 ± 9 ms during conventional CRT (n = 14, P < .001), to 143 ± 7 ms during left ventricular septal pacing (LVSP) in combination with CVP for CRT (LVSP-CRT) (n = 9, P < .001), and further to 122 ± 10 ms during BSP-CRT (n = 12, P < .001). Notably, among 7 patients in whom both LVSP and BSP were achieved, BSP-CRT outperformed LVSP-CRT at QRS narrowing by 16% (P < .001). At 3-month follow-up, left ventricular ejection fraction improved from 29 ± 6% to 41 ± 8% (P < .001). CONCLUSIONS: BSP-CRT resulted in superior acute electrical synchronization to conventional CRT and might be considered as an alternative to conventional CRT with QRS more than 130 ms.

[Surgery for obstructive hypertrophic cardiomyopathy: challenge and future].

After more than 60 years of development, with the deepening of the pathophysiological understanding of obstructive hypertrophic cardiomyopathy, the extent and resection thickness of myectomy have increased significantly. Myectomy combined with the correction of anomalies of the mitral valve apparatus has become the standard treatment of obstructive hypertrophic cardiomyopathy. Only a few centers worldwide can routinely perform it due to the difficulty. Because of the advances of new drugs and interventional therapy, the development of surgical treatment faces many challenges. At the same time, generations of cardiovascular surgeons are constantly trying to promote septal myectomy, including developing devices and the surgical field, as well as improving surgical planning by advanced technology. At present, the superior long-term efficacy of septal myectomy has been confirmed. It is necessary to work together to promote the treatment of hypertrophic obstructive cardiomyopathy, so as to guard people's health.

Why is the patient still symptomatic after myectomy for HCM!

We describe the case of a young female patient with hypertrophic cardiomyopathy (HCM) with a dual chamber implantable cardioverter defibrillator (ICD), and complete heart block from a prior septal ablation procedure. Due to persistent left ventricular outflow tract (LVOT) obstruction and symptoms, she underwent surgical myectomy. Her exertional symptoms continued despite improved LVOT flow parameters. A comprehensive evaluation, including ICD interrogation, helped arrive at the correct diagnosis and treatment plan.

Hypertrophic obstructive cardiomyopathy with a basal septal thickness of 16 mm or less: clinical characteristics and surgical results.

PURPOSES: To characterize the clinical features and surgical outcomes of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) in patients with only mild septal hypertrophy. METHODS: The clinical characteristics and surgical outcomes of 53 HOCM patients with a basal septal thickness ≤ 16 mm (mild group) were compared with those of 128 HOCM patients with a basal septal thickness > 16 mm (control group). RESULTS: The mild group had a greater prevalence of mitral subvalvular anomalies than the control group (79.2% vs. 6.3%, p < 0.001). Neither iatrogenic septal perforation nor inadequate septal myectomy was observed after myectomy in the mild group. There were no deaths during a median follow-up of 10 months. Transthoracic echocardiography 6 months after myectomy revealed a significant decrease in maximum gradients in both groups, from baseline 90.5 ± 21.5 mmHg to 10.3 ± 4.4 mmHg in the mild group (p < 0.001) and from 95.0 ± 22.0 mmHg to 12.0 ± 5.9 mmHg (p < 0.001) in the control group. Neither residual obstruction nor residual mitral regurgitation was recorded in the mild group. CONCLUSIONS: Symptomatic patients with hypertrophic obstructive cardiomyopathy and mild septal hypertrophy may have a higher prevalence of mitral subvalvular abnormalities. Mitral subvalvular management during myectomy can achieve outstanding results for these patients.

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.

Videoscope-assisted transaortic myectomy in patients with hypertrophic cardiomyopathy with complex left ventricular anatomy.

BACKGROUND: The transaortic approach is the most common method of septal myectomy. However, difficulties arise due to a limited view of the surgical field. Here, we report our experience with videoscope-assisted transaortic myectomy. METHODS: We reviewed myectomy operations that were performed between July 2015 and June 2019 at Chung-Ang University Hospital, Seoul, South Korea. Patients who previously had cardiac surgery, alcohol septal ablation, or concomitant disease which required combined surgery, were excluded. Among the 21 patients included, 10 patients underwent videoscope-assisted transaortic myectomy (VA group), and 11 patients underwent myectomy in a conventional manner (CO group). The preoperative data, echocardiographic images, operative records, and postoperative outcomes of these patients were reviewed. RESULTS: There were no differences in baseline characteristics between groups VA and CO. The main indications for videoscope-assisted transaortic myectomy in group VA were midventricular septal muscle resection (70%), abnormal papillary muscle resection (40%), and abnormal chordal connection resection (30%). Eight (80%) patients had multiple indications for videoscope-assisted transaortic myectomy. There was no surgical mortality in either group. Postoperative patients showed less than moderate mitral regurgitation and a New York Heart Association class either III or IV. There were no differences in hospital days (9.5 vs. 12.0 days; p = .383), nor postoperative pressure gradient (14 vs. 15 mmHg; p > .99). CONCLUSIONS: Videoscope-assisted transaortic myectomy is an effective surgical technique in selective hypertrophic cardiomyopathy patients with complex intraventricular anatomy, diffuse hypertrophy, and midventricular obstruction.

Impact of Septal Myectomy Volume on Mitral-Valve Replacement Rate in Hypertrophic Cardiomyopathy Patients.

OBJECTIVE: Mitral regurgitation (MR) induced by systolic anterior motion in patients with hypertrophic cardiomyopathy (HCM) can frequently be abolished with a proficient septal myectomy (SM) without the need for mitral-valve replacement (MVR). ACC guidelines stress the importance of volume in improving outcomes after SM, but there is a lack of data measuring the impact of volume on the need for MVR during SM. This study was designed to assess the impact of institutional volume on MVR rates using national outcomes data. METHODS: The Nationwide Inpatient Sample was queried from 1998 to 2011 and a total of 6,207 patients had a diagnosis of HCM and a procedure code for SM. Outcomes were compared between patients who underwent SM (group I) and SM and MVR (group II). Furthermore, patients were stratified into 3 groups based on the number of SMs at the performing institution: low experience (1-24 cumulative SMs), medium experience (25-49 SMs), and high experience (>50 SMs). These patients underwent multivariable analysis to determine the impact of institutional volume on MVR rate. RESULTS: The total MVR rate was 26%. Perioperative outcomes were worse, i.e., there were higher rates of mortality, kidney injury, and urinary complications, in group II than in group I. Only 37.6% of patients were operated on at institutions meeting the guideline criteria of >50 cumulative SMs. When compared to patients in the high-experience group, patients in the low- (OR 2.7, 95% CI 2.3-3.2, p < 0.05) and medium-experience (OR 3.0, 95% CI 2.5-3.6, p < 0.05) groups were more likely to undergo MVR. CONCLUSION: Compared to reports from SM reference centers, national data suggest that MVR rates are quite high at SM. Patients undergoing SM at centers that do not meet the guideline standard have >2.5× the odds of undergoing MVR compared to those operated on at guideline-endorsed centers.

Conservative management of a rare case of atrial septal hematoma after pediatric cardiac surgery.

Atrial septal hematoma is uncommon complication that may happen after any cardiac intervention. Although it is rare, it can pose a challenging situation in the postoperative care. Multiple management approaches has been described with different outcomes. Here we are reporting a boy, aged 13 years, with dilated aortic root who underwent aortic root replacement with valve preservation. Postoperative course was complicated by atrial septal hematoma. A nonsurgical management approach was chosen based on the patient clinical condition. Regression in size with complete resolution of the hematoma was observed during the follow up.

Surgical ablation of atrial fibrillation in hypertrophic obstructive cardiomyopathy: Outcomes of a tailored surgical approach.

OBJECTIVE: To assess outcomes of concomitant ablation for atrial fibrillation (AF) in patients with preoperative AF undergoing septal myectomy for hypertrophic obstructive cardiomyopathy. METHODS: From 2005 to 2016, 67 patients underwent concomitant ablation for AF and septal myectomy and had a follow-up beyond a 3-month blanking period. Ablation strategy (pulmonary vein isolation [PVI], modified Cox-maze III [CM-III], or Cox-maze IV [CM-IV]) was tailored to preoperative AF burden, with high AF burden defined as persistent AF or need for cardioversion. AF recurrence was analyzed as a time-related event and predictors of recurrence identified using a random forest methodology. RESULTS: A total of 38 patients (57%) had low AF burden and 29 (43%) high burden. Patients with low AF burden most frequently underwent PVI (68%). Patients with high AF burden more frequently underwent CM-III (62%) or CM-IV (35%). Besides the preoperative AF burden, baseline characteristics were similar between patients receiving CM-III, CM-IV, and PVI. After surgery, the maximum provoked left ventricular outflow tract (LVOT) gradient decreased from 99 ± 34 to 18 ± 11mm Hg (P < .001). Eight patients (12%) required a permanent pacemaker. Cumulative AF recurrence at 1, 2, and 5 years was 11%, 22%, and 48%, respectively. Age, low preoperative resting LVOT gradient, and large left atrial diameter were predictors of AF recurrence. CONCLUSIONS: Surgical outcomes of concomitant ablation for AF and septal myectomy are good, although recurrence of AF by 5 years is frequent.

The first case of combined heart-liver transplantation in a patient with alveolar echinococcosis.

We report a rare case of liver alveolar echinococcosis with an invasion of the hepaticocaval confluence, inferior vena cava, pericardium, right atrium, atrial septum, and superior vena cava, and its successful treatment by combined heart-liver transplantation.

Robotic trans-mitral septal myectomy and papillary muscle reorientation for HOCM combined with or without mitral valve repair: Technical aspects - How we do it.

Hypertrophic obstructive cardiomyopathy (HOCM) is one of the more common genetic disorders. The pathophysiology and natural history of the disease have been well studied. Left ventricular outflow tract obstruction (LVOTO) and systolic anterior motion (SAM) of the anterior mitral leaflet can result in sudden cardiac death, progressive heart failure and arrythmias. Surgical septal myectomy for HOCM is the standard of care and is routinely performed through a median sternotomy. Septal myectomy has also been performed using the trans-atrial, trans-mitral approach either directly or with robotic assistance. In cases with severe LVOT obstruction in the setting of only mild to moderate proximal septal hypertrophy, intrinsic problems with the mitral valve contribute. Typically, these are hypermobile papillary muscles and or excessive height of the anterior mitral leaflet. Combining septal myectomy with reorientation of hypermobile anteriorly positioned papillary muscles has shown to prevent SAM and thereby additionally decrease the subvalvular aortic outflow obstruction. Our extensive experience in both septal myectomy and robotic mitral valve repair has given us a different perspective in approaching the primary mitral regurgitation in HOCM patients where a combined septal myectomy, papillary muscle reorientation and complex mitral valve repair has been safely performed using the less invasive robotic-assisted approach.Our objective here is to discuss the technical aspects of the procedure.

Three-dimensional printing facilitates surgical planning for resection of an atypical cardiac myxoma.

BACKGROUND: Cardiac myxomas are common and account for 50% of primary intracardiac tumors. Atypical locations of cardiac myxoma increase the risk of intraoperative iatrogenic injuries. Herein, we report a case of using three-dimensional printing (3D) to facilitate the removal of an atypical cardiac myxoma in a 63-year-old woman. METHODS AND RESULTS: Mass in the high posterior atrial septum was confirmed through imaging. Due to the potential involvement of the mass to surrounding vital structures, 3D printing of the cardiac mass was performed. The tumor was completely resected via median sternotomy and the resulting defect was repaired with the bovine pericardium. The patient had an uncomplicated postoperative course except for the development of sick sinus syndrome. One-year follow-up showed no tumor recurrent. CONCLUSION: 3D printing technology in patients with atypical cardiac tumors enhances our understanding of the extent of the tumor invasion and facilitates planning the operation to avoid intraoperative complications.

Lipomatous hypertrophy of the interatrial septum is a pathologic, not an anatomic diagnosis.

BACKGROUND AND AIM: Lipomatous hypertrophy of the interatrial septum (LHIS), a fatty tumor, is usually diagnosed on both echo and CT/MRI imaging. Cases of LHIS located outside of the interatrial septum are extremely rare and rarer still are these cases large enough to cause symptoms. The clinical literature demonstrates a misunderstanding that fatty tumors outside the intra-atrial area represent lipomas. However, pathologic understanding of these fatty tumors is clear and is based on microscopic findings. METHODS: The tumor was removed by diving the base of attachment at the left ventricular apex via a median sternotomy on cardiopulmonary bypass. RESULTS: The patient made an uneventful recovery and remains well at 6 months postoperatively. CONCLUSIONS: On rare occasions, LHIS can arise from outside the interatrial septum. An LHIS can be differentiated from a lipoma by the presence of entrapped cardiac myocytes in LHIS, making it a pathological, rather than an anatomic, diagnosis.

How to repair an acquired Gerbode defect using an aortic root xenograft.

A 74-year old female patient presented with a 3-week history of fever, general weakness, and later developed complete heart block. On admission, the patient was febrile (temperature of 39°C) and tachypnoeic (respiratory rate of 29/min) with oxygen saturation of 95% on 2 L of oxygen. Her heart rate was 60 beats/min (VVI pacing), arterial blood pressure was 135/60 mm Hg and the Glasgow Coma Scale was 15. On chest auscultation, she had a harsh systolic murmur over her left precordium and bilateral rales. Blood tests demonstrated moderate anemia (hemoglobin of 95 g/L), leucocytosis (white blood cell count of 13.13 x 10^9/L), hypoalbuminemia (albumin concentration of 18 g/L), normal liver function tests and creatinine clearance of 45 ml/min. Computed tomography aortography demonstrated an irregular mass arising from the aortic root that extended into the right atrium (RA) and a fistulous tract (the Gerbode defect) between the left ventricular outflow tract (LVOT) and the right ventricle (RV). Transoesophageal echocardiography showed large vegetation in the RA and left to right cardiac shunt through the Gerbode defect from the LVOT to the RA and the RV. Using cardiopulmonary bypass, the patient underwent resection of the aortic cusps, debridement of the aortic root, septal and anterior leaflets of the tricuspid valve, and the membranous septum. The Gerbode defect was closed with an autologous pericardial patch, then a sliding annuloplasty of the septal leaflet of the tricuspid valve was performed. Finally, the aortic root was replaced with a 23 mm Freestyle xenograft.

Septal ablation acutely reduces outflow obstruction after transcatheter mitral valve replacement.

Transcatheter mitral valve replacement (TMVR) is an emerging treatment of mitral valve pathology in patients that are not candidates for conventional surgical approaches. Higher rates of left ventricular outflow tract obstruction (LVOTO) may occur following TMVR and its occurrence is an independent predictor of mortality. We present a case of severe mitral stenosis and annular calcification that was treated with a balloon-expandable Sapien S3 valve in the mitral position delivered through surgical port-access approach, which resulted in postoperative LVOTO. The LVOTO was successfully treated with alcohol septal ablation with immediate reduction in outflow tract gradients and long-term resolution.

Predictors of long-term outcome after septal myectomy in symptomatic hypertrophic obstructive cardiomyopathy patients with previous alcohol septal ablation and residual obstruction.

BACKGROUND AND AIM: Recently alcohol septal ablation (ASA) has emerged as an alternative treatment for drug-refractory hypertrophic obstructive cardiomyopathy (HOCM) and a subgroup of HOCM patients with previous ASA may need myectomy. However, subsequent outcome and mechanism of residual obstruction has not been determined. This study aims to determine outcome after myectomy and mechanism of residual obstruction in HOCM patients with previous ASA. METHODS: From February 2009 to June 2017, 38 HOCM patients with previous ASA underwent surgical septal myectomy at our institution. Seventy-six patients who underwent surgical septal myectomy initially were included as the comparison group through one-to-two propensity score matching method. RESULTS: Fourteen available cardiac magnetic resonance images revealed inferior location and small area of infarcted myocardium induced by ASA in 12 patients and outside targeted location in two patients. During follow-up (median, 2.4; maximum, 7.8 years), event-free survival at 7 years was 83.2% in the previous ASA group and 94.6% in the comparison group, respectively (P = 0.0378). Multivariable analysis indicated previous ASA (hazard ratio, 4.28; 95% confidence intervals [CI], 1.20-15.26; P = 0.025) and postoperative left ventricular end-diastolic diameter (hazard ratio, 1.14; 95% CI, 1.05-1.23; P = 0.002) were independent predictors of adverse events. CONCLUSIONS: This study demonstrated that uncontrollable extent and location of infarcted myocardium induced by ASA may attribute to residual obstruction after previous ASA, and the long-term event-free survival after myectomy was inferior. It may provide special precaution to patient selection and the increased number of ASA practiced worldwide.

Adipose tumors of the heart.

BACKGROUND: Primary cardiac adipose tumors are rare. There are two distinct pathologically defined entities that represent this tumor type: lipoma and lipomatous hypertrophy of the interatrial septum (LHIS). We present a single-center experience with these tumors and demonstrate that the location may not correspond to the pathologic diagnosis. METHODS: A retrospective review of a prospectively collected cardiac surgery database from January 1990 to July 2016 identified 254 cases of surgically treated primary cardiac tumors at our Institution. Of these, 06/254 (2%) were primary adipose tumors. RESULTS: In 3/6 (50%) cases, patients were asymptomatic or had symptoms referable to other known intracardiac lesions. Five patients (83%) had preserved ventricular function. In 4/6 cases (67%), the tumor was identified preoperatively. All patients presented in New York Heart Association functional class ≤2. Pathologic diagnosis of LHIS was made in 5/6 cases (83%), with 2/5 LHIS (40%) located in the interatrial septum. A bovine pericardial patch was utilized for reconstruction following tumor resection in 3/6 cases (50%). Mean cardiopulmonary bypass time was 88 ± 43 min. All the patients tolerated the procedure well without any postoperative complications. CONCLUSIONS: Primary cardiac adipose tumors are responsible for a small portion of all primary heart tumors. Surgical resection provided excellent outcomes, and did not affect cardiac performance, in spite of the need for extensive resections. LHIS was identified in locations other than the interatrial septum and was usually symptomatic.