Dynamic Left Ventricular Outflow Tract Research Articles

A Case of Forming Test for the Diagnosis of PFO Combined Dynamic Left Ventricular Outflow Tract Stenosis after Occlusion

This patient was diagnosed with Patent Foramen Ovale (PFO) due to recurrent headaches, and her headaches improved significantly after oval foramen occlusion, but a grade 3/6 coarse murmur was heard in the aortic valve auscultation area, and left ventricular outflow tract stenosis was suggested by cardiac ultrasound. This change may be related to a variety of factors, suggesting that we should do a good preoperative assessment of the patient; intraoperative operation as gentle as possible to reduce the damage to the surrounding tissues; postoperative operation should be strengthened to avoid the progression of the inflammatory process, and at the same time to pay attention to the patient's symptoms, signs and dynamics of the relevant examinations to reduce the incidence of complications.

Resection of hypertrophic papillary muscles and mitral valve replacement in a patient with midventricular hypertrophic obstructive cardiomyopathy – a new approach

Midventricular hypertrophic obstructive cardiomyopathy (HOCM) is characterized by hypertrophy of the interventricular septum (IVS) and - in rare cases - of the papillary muscles (PM), which subsequently can cause dynamic left ventricular outflow tract obstruction (LVOTO) and severe heart failure symptoms. We report on a rare case of a 44-year-old patient suffering from midventricular HOCM with hypertrophic anterolateral PM and an additional chorda between the PM and the IVS.We describe a new surgical approach via right anterolateral thoracotomy in 3-dimensional (3D) video-assisted minimal-invasive technique with resection of hypertrophic PMs as well as the entire mitral valve-apparatus and valve replacement avoiding septal myectomy and potentially associated complications. After an uneventful procedure clinical symptoms improved from NYHA III-IV at baseline to NYHA 0-I postoperatively and remained stable over a follow-up period of 24 months. Therefore, the presented technique may be considered as a new and alternative approach in patients with hypertrophic PMs and hypertrophic IVS as subtype of midventricular HOCM.

Obstructive hypertrophic cardiomyopathy: a review of new therapies.

Hypertrophic cardiomyopathy (HCM) is a phenotypically heterogeneous disease with a genetic basis and variable penetrance. The hallmarks of HCM include dynamic left ventricular outflow tract obstruction, typically caused by asymmetric septal hypertrophy. However, abnormal papillary muscle placement, abnormal mitral valve and subvalvular apparatusand apical hypertrophic forms have also been described. Typical medical treatment has been stagnant for decades, although there have been significant advances in surgical treatment of patients with obstructive HCM. Herein, we describe a new class of drugs targeting the specific pathophysiology of HCM.

311.7: Hypertrophic hearts develop dynamic left ventricular outflow tract obstruction after orthotopic pig-to-baboon xenotransplantation

311.7: Hypertrophic hearts develop dynamic left ventricular outflow tract obstruction after orthotopic pig-to-baboon xenotransplantation

Pulmonary hypertension-related dynamic left ventricular outflow tract obstruction.

Pulmonary hypertension-related dynamic left ventricular outflow tract obstruction.

Focused Cardiac Ultrasound Identification of Dynamic Left Ventricular Outflow Tract Obstruction.

Focused Cardiac Ultrasound Identification of Dynamic Left Ventricular Outflow Tract Obstruction.

Xenografts Show Signs of Concentric Hypertrophy and Dynamic Left Ventricular Outflow Tract Obstruction After Orthotopic Pig-to-baboon Heart Transplantation.

Orthotopic cardiac xenotransplantation has seen substantial advancement in the last years and the initiation of a clinical pilot study is close. However, donor organ overgrowth has been a major hurdle for preclinical experiments, resulting in loss of function and the decease of the recipient. A better understanding of the pathogenesis of organ overgrowth after xenotransplantation is necessary before clinical application. Hearts from genetically modified ( GGTA1-KO , hCD46/hTBM transgenic) juvenile pigs were orthotopically transplanted into male baboons. Group I (control, n = 3) received immunosuppression based on costimulation blockade, group II (growth inhibition, n = 9) was additionally treated with mechanistic target of rapamycin inhibitor, antihypertensive medication, and fast corticoid tapering. Thyroid hormones and insulin-like growth factor 1 were measured before transplantation and before euthanasia, left ventricular (LV) growth was assessed by echocardiography, and hemodynamic data were recorded via a wireless implant. Insulin-like growth factor 1 was higher in baboons than in donor piglets but dropped to porcine levels at the end of the experiments in group I. LV mass increase was 10-fold faster in group I than in group II. This increase was caused by nonphysiological LV wall enlargement. Additionally, pressure gradients between LV and the ascending aorta developed, and signs of dynamic left ventricular outflow tract (LVOT) obstruction appeared. After orthotopic xenotransplantation in baboon recipients, untreated porcine hearts showed rapidly progressing concentric hypertrophy with dynamic LVOT obstruction, mimicking hypertrophic obstructive cardiomyopathy in humans. Antihypertensive and antiproliferative drugs reduced growth rate and inhibited LVOT obstruction, thereby preventing loss of function.

Exaggerated myocardial torsion may contribute to dynamic left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

Dynamic left ventricular (LV) outflow tract obstruction (LVOTO) is associated with symptoms and increased risk of developing heart failure in hypertrophic cardiomyopathy (HCM). The association of LVOTO and LV twist mechanics has not been well studied in HCM. The aim of the study was to compare the pattern of LV twist in patients with HCM associated with asymmetrical septal hypertrophy with and without LVOTO. Echocardiography (including speckle tracking) was performed in 212 patients with HCM, divided according to the absence (n = 130) or presence (n = 82) of LVOTO (defined as peak pressure gradient ≥30 mmHg either at rest and/or with Valsalva manoeuvre). Patients with LVOTO were older, had smaller LV dimensions, a higher LV ejection fraction (LVEF), a longer anterior mitral valve leaflet length, and a higher early transmitral pulsed wave to septal tissue Doppler velocity ratio (E/E'). A univariate analysis showed that peak twist was significantly higher in patients with LVOTO compared with patients without LVOTO (19.7 ± 7.3 vs. 15.7 ± 6.0, P = 0.00015). Peak twist was similarly enhanced in patients with LVOTO, manifesting only during Valsalva (19.2 ± 5.6, P = 0.007) and patients with resting LVOTO (19.9 ± 8.0, P = 0.00004) compared with patients without LVOTO (15.7 ± 6.0). A stepwise forward logistic regression analysis showed that LVEF, LV end-systolic dimension indexed to body surface area, anterior mitral valve leaflet length, E/E', and peak twist were all independently associated with LVOTO. This study demonstrates that increased peak LV twist is independently associated with LVOTO in patients with HCM. Peak twist was similarly exaggerated in patients with only latent LVOTO, suggesting that it may play a contributory role to LVOTO in HCM.

The role of cleft and/or indentation in mitral regurgitation etiology detected by three-dimensional echocardiography in patients with hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Aim The pathophysiology of hypertrophic cardiomyopathy (HCM) consists of dynamic left ventricular outflow tract obstruction, myocardial ischemia, diastolic dysfunction and mitral regurgitation. Mitral regurgitation may be secondary to left ventricular outflow tract obstruction (LVOTO) or related to primary mitral valve pathologies. Three-dimensional (3D) echocardiography has revolutionized imaging of the mitral valve by allowing real-time direct visualization of the mitral valve leaflets in HCM. 3D echocardiography has been using increasingly to evaluate mitral valve clefts and indentations. The aim of this study is to define the frequency of clefts and indentations, and to determine their contribution to mitral regurgitation in patients who are diagnosed HCM and moderate or severe mitral regurgitation by imaging with 3D echocardiography. Methodology A total of 74 patients who were diagnosed with HCM in accordance with current guidelines and moderate or severe mitral regurgitation who underwent 3D transesophageal echocardiography (TEE) between Aug 2018 and May 2022 were retrospectively enrolled. In the control group, 200 patients with moderate or severe mitral regurgitation without diagnosis of HCM were selected. Two groups were compared with each other by demographical, echocardiographical features and cardiac magnetic resonance images. Results Our final patient population was a total of 50 patients after exclusion criteria. The number of 24 (48%) was female and the number of 26 (52%) was male. There was 89 female patient (44,5%) and 111 male patient (55,5%) in the control group. Patients who are diagnosed HCM were younger compared with the control group (mean age 54,5 ±14 year for HCM patients versus 61±14 year for control patients). Cleft/indentation was present in 14 (28%) HCM patients versus 31 (15,6%) in control patients. It was determined that cleft/indentation was more prevelant in HCM patients (p = 0,041). When we evaluate the direction of mitral regurgitation jet with the presence of celft/indentation, there was a significant association between anteriorly directed mitral regürgitation jet and the presence of cleft (p = 0,003). Conclusion In this study, the frequency of cleft/indentations in HCM patients was 28%, it means that cleft/indentation is more often in HCM patients according to the patients who have moderate or severe mitral regurgitation without HCM. When the cleft exists, it affects on the direction of mitral regurgitation and leads to anteriorly directed jet. On the other hand, the indentations have no effect on the direction of mitral regurgitation jet. As a result, 3D mitral valve modeling can be helpful to make a differential diagnosis in HCM patients with anteriorly directed mitral regurgitation jet. Morover, there is no significant efficacy in management of mitral regurgitation by using 3D mitral valve modeling to describe indentations solely.

P121 MITRAL VALVE STENOSIS ASSOCIATED WITH LEFT VENTRICULAR OUTFLOW TRACT OBSTRUCTION: A TERRIBLE COMBINATION WITH A DIFFICULT TREATMENT

Abstract Case n. 1 A 77 year–old woman with obstructive hypertrophic cardiomyopathy who had undergone alcohol septal ablation with a reduction in dynamic left ventricular outflow tract (LVOT) gradient from 95 to 65 mmHg was hospitalized for pulmonary oedema. Echocardiography and cardiac catheterization confirmed the presence of obstructive hypertrophic cardiomyopathy with a dynamic gradient of 65 mmHg, and identified a severe calcific mitral stenosis (3D planimetric area= 0,9 cm2). There was severe postcapillary pulmonary hypertension (pulmonary artery mean pressure of 60 mmHg and pulmonary capillary wedge pressure of 26 mmHg). The patient underwent a combined surgical intervention of mitral valve replacement (Epic 27 mm bioprosthesis) and surgical septal myectomy via a mini–thoracotomic approach. After the intervention there were dehiscence and infection of the thoracotomy and right inguinal surgical wounds, septic shock, hyporexia (with marked cachexia), emotional instability and delirium. After 21 days of hospitalization in the ICU, the patient was transferred to a medical department and died seven days later. Case n. 2 A 82 year–old woman with severe mitral stenosis associated with marked left ventricular hypertrophy and LVOT obstruction was admitted for heart failure and worsening renal function. Her comorbidities included diabetic neuropathy and stage 4 chronic kidney disease. Cardiac catheterization excluded significant coronary artery disease; mitral valve area was 1 cm2, and LVOT gradient was 75 mmHg. Pulmonary artery mean pressure was 32 mmHg, pulmonary capillary wedge pressure was 25 mmHg, and right atrial mean pressure was 8 mmHg. She was deemed a high–risk surgical candidate. The patient therefore was treated initially with peritoneal dialysis. However she demonstrated persisting pulmonary congestion. An atrial septostomy inserting a 8–mm Atrial Flow Regulator was subsequently performed, with an immediate reduction of capillary wedge pressure to 18 mmHg. In the following 18 months the patient had no more hospitalizations for heart failure. Conclusion The association between mitral stenosis and LVOT obstruction is associated with elevated capillary wedge pressure and frequent episodes of heart failure. Surgical intervention remains the first therapeutical option. Nevertheless, in older patients, the association between atrial septostomy and peritoneal dialysis may represent a valuable solution, with a lower operative risk.

大動脈弁逆流と左室流出路狭窄が併発した犬に対して観血的動脈血圧測定を用い術中循環管理を実施した一例

A 12-year-old mix-breed dog was presented with anal sac tumor and scheduled for left anal sacculectomy. Pre-operative echocardiography revealed that the dog had moderate aortic regurgitation (AR), mild mitral valve regurgitation, and dynamic left ventricular outflow tract obstruction. A hypotension of invasive arterial blood pressure (IABP) following low mean and diastolic blood pressure during surgery was suspected to be related to AR and treated by heart rate titration with atropine and dopamine infusion. Accurate blood pressure assessment with IABP and extrapolation treatment strategy of hypotension related to AR by human medicine are useful for anesthetic management in dogs with AR.

Systolic Anterior Motion of the Mitral Valve in the Presence of Annular Calcification

Mitral annular calcification (MAC) has been reported as a possible cause of systolic anterior motion (SAM) of the mitral valve and dynamic left ventricular outflow tract (LVOT) obstruction. While morphologic features predisposing to SAM in other clinical settings have been described, patients with MAC+SAM have not been systematically investigated. We hypothesized that bulky calcium deposits in the mitral annulus could displace the valve toward the septum, thus promoting development of SAM. We studied 30 patients with severe MAC who had SAM with septal contact. Three comparator groups (matched for age and sex) were developed: 30 controls without MAC or SAM, 30 with severe MAC but no SAM, and 30 with SAM but no MAC. Significant differences were found across groups for mitral valve coaptation point-septal distance (CSD), anterior mitral leaflet (AML) length, left ventricular diastolic dimension, and ejection fraction. Comparing all MAC subjects (n=60) with controls, CSD was less (20.5±4.1 vs 23.2±3.7mm, P=.003) and ejection fraction was higher (67.7%±7.8% vs 60.9%±6.4%, P<.0001) in MAC patients. Within MAC subjects AML was longer (21.9±3.0 vs 17.4±2.2mm, P<.0001) and CSD was smaller (18.0±2.7 vs 23.1±3.6mm, P<.0001) when SAM was present despite similar height of the calcium bar in the 2 MAC groups (12.4±2.9 vs 11.1±3.1mm, P=.11). Regression analysis confirmed AML length and CSD as independent predictors of SAM. MAC+SAM patients also had more echocardiographic risk factors for SAM (acute aortomitral angle, small LVOT, long AML, small CSD, and presence of a septal bump) than MAC/no-SAM patients (3.4±0.9 vs 1.8±1.0, P<.0001). Bulky MAC appears to contribute to dynamic LVOT obstruction when it accumulates in such a way that the mitral valve is displaced anteriorly toward the septum. However, other features are also associated with SAM in these patients, particularly a long AML. A combination of morphologic features and favorable hemodynamics may be needed for SAM to develop in patients with severe MAC.

786 SYSTOLIC ANTERIOR MOVEMENT OF MITRAL VALVE: NOT ONLY HYPERTROPHIC CARDIOMYOPATHY, BUT ALSO CARDIAC AMYLOIDOSIS

Abstract A 71 years-old man was diagnosed with lambda light chain multiple myeloma evolving from monoclonal gammopathy of unknown significance during hematological follow-up. Serum creatinine and blood urea were normal, but proteinuria was significant. A subsequent renal biopsy showed amyloid deposits in renal glomeruli. He had no comorbidities or previous cardiologic history. To provide a complete diagnostic work-up, an echocardiogram was performed, showing marked and asymmetric left ventricular hypertrophy (interventricular septum diastolic thickness IVSd 15 mm) with dynamic left ventricular outflow tract obstruction (LVOTO) due to an incomplete systolic anterior motion (SAM) of mitral valve. ECG showed sinus rhythm with 1st degree atrio-ventricular block; notably, there was no electrocardiographic sign of left ventricular hypertrophy. Therefore, a Cardiac Magnetic Resonance (CMR) was performed, showing left ventricular hypertrophy (interventricular septum thickness 15 mm) with normal contractility. Mild left atrial enlargement and thickening of the interatrial septum were found, together with mild circumferential pericardial effusion. No perfusion defects were recorded, but late gadolinium enhancement (LGE) pattern was not assessable because of difficult myocardial signal nulling point. These findings were consistent with cardiac amyloidosis (CA). By the time, histological demonstration of amyloid was mandatory, so an endomyocardial biopsy was performed. Amyloid deposits were found to be in the myocardial interstitial space and into the myocardial vessel walls. Immunohistochemical staining revealed diffuse and high reactivity for lambda free light chains and moderate reactivity for kappa chains. No transthyretin was found in the specimens. Finally, a diagnosis of AL amyloidosis with cardiac and renal involvement associated with lambda light chain multiple myeloma was made and chemotherapy with bortezomib, thalidomide and dexamethasone (VTD) was started. During the cardiologic follow-up, three syncope with prodromal symptoms have occurred. In all these circumstances, no arrhythmias were found at prolonged ECG Holter monitoring. Echocardiogram showed a progression of the dynamic outflow obstruction to 80 mmHg and increasing mitral regurgitation associated with complete systolic anterior motion of the valve. Given the echocardiographic features and the clinical events, we performed a genetic blood test which excluded sarcomeric genes mutations. Also, familial screening with ECG and echocardiogram was negative. A better management of pharmacological therapy, together with avoidance of hypovolemia and supportive treatment of anemia finally relieved patient's symptoms. Conclusions we presented this case to underline that, although rare, cardiac amyloidosis can resemble other hypertrophic cardiomyopathies with left ventricular outflow tract obstruction due to SAM of the mitral valve and irregular septal hypertrophy, caused by amyloid deposits. Most of these cases are seen in the senile transthyretin type, but sometimes they are observed in AL patients. Nowadays, it is crucial to diagnose these patients correctly as early treatment is critical for survival in this population.

Prevalence and Prognosis of Atenolol-Responsive Systolic Anterior Motion of the Septal Mitral Valve Leaflet in Young Cats with Severe Dynamic Left Ventricular Outflow Tract Obstruction.

Severe dynamic left ventricular outflow tract obstruction (DLVOTO) secondary to the systolic anterior motion of the septal mitral valve leaflet (SAM) can result either from congenital mitral valve disorders or left ventricular concentric hypertrophy of any cause, in cats commonly hypertrophic cardiomyopathy (HCM). Though HCM cannot be reversed, the question remains whether atenolol can cure cats with severe DLVOTO resulting from a presumed mitral valve dysplasia. In this retrospective case series, client-owned asymptomatic cats younger than 1.5 years with echocardiographic evidence of SAM and severe DLVOTO were included. Oral atenolol therapy and recheck echocardiography after 2-3 months were recommended. The owners and referring veterinarians were called for long-term follow-up information. Of the 28 included cats, 23 were treated with atenolol. Recheck echocardiography performed in 17 cats showed a resolution of SAM in 47%. In the long term, SAM remained absent in only 9% of the treated cats. Cardiac-related death occurred in 26% of the atenolol-treated cats. The long term benefit of twice-daily atenolol therapy was documented in 9% of cats. Whether the cats where atenolol failed to resolve DLVOTO on long-term had HCM, or a therapy-resistant congenital primary mitral valve disorder remains unclear.

What is the effect of catecholamines on diastolic function in patients with pheochromocytoma and paraganglioma?

Pheochromocytoma is a rare form of secondary hypertension characterized by excessive production of catecholamines typically due to a benign tumor in the adrenal medulla. Among the potential cardiac repercussions of pheochromocytoma and paraganglioma, previous studies described echocardiographic abnormalities such as dynamic left ventricular outflow tract obstruction (i), cardiomyopathy (ii, iii, iv), reversible dilatation of the left ventricle (v) and left ventricular functional changes (vi) in patients with pheochromocytoma.

Evidence of Advanced Pulmonary Vascular Remodeling in Obstructive Hypertrophic Cardiomyopathy With Pulmonary Hypertension

Elevated mean pulmonary artery pressure (mPAP) is common in patients with hypertrophic cardiomyopathy (HCM) and heart failure symptoms. However, dynamic left ventricular (LV) outflow tract obstruction may confound interpretation of pulmonary hypertension (PH) pathophysiologic features in HCM when relying on resting invasive hemodynamic data alone. Do structural changes to the lung vasculature clarify PH pathophysiologic features in patients with HCM with progressive heart failure? Clinical data and ultrarare lung autopsy specimens were acquired retrospectively from the National Institutes of Health (1975-1992). Patients were included based on the availability of lung tissue and recorded mPAP. Discarded tissue from rejected lung donors served as control specimens. Histomorphology was performed on pulmonary arterioles and veins. Comparisons were calculated using the Student t test and Mann-Whitney U test; Pearson correlation was used to assess association between morphometric measurements and HCM cardiac and hemodynamic measurements. The HCM cohort (n= 7; mean ± SD age, 43 ± 18 years; 71%men) showed maximum mean ± SD LV wall thickness of 25 ± 2.8mm, mean ± SD outflow tract gradient of 90 ± 30mmHg, median mPAP of 25mmHg (interquartile range [IQR], 6mmHg), median pulmonary artery wedge pressure (PAWP) of 16mmHg (IQR, 4mmHg), and median pulmonary vascular resistance of 1.8 Wood units (WU; IQR, 2.4 WU). Compared with control samples (n= 5), patients with HCM showed greater indexed pulmonary arterial hypertrophy (20.7 ± 7.2%vs49.7 ± 12%; P< .001) and arterial wall fibrosis (11.5 ± 3.4mm vs21.0 ± 4.7mm; P< .0001), which correlated with mPAP (r= 0.84; P= .018), PAWP (r= 0.74; P= .05), and LV outflow tract gradient (r= 0.78; P= .035). Compared with control samples, pulmonary vein thickness was increased by 2.9-fold (P= .008) in the HCM group, which correlated with mPAP (r= 0.81; P= .03) and LV outflow tract gradient (r= 0.83; P= .02). To the best of our knowledge, these data demonstrate for the first time that in patients with obstructive HCM, heart failure is associated with pathogenic pulmonary vascular remodeling even when mPAP is elevated only mildly. These observations clarify PH pathophysiologic features in HCM, with future implications for clinical strategies that mitigate outflow tract obstruction.

Mitral valve abnormalities in decedents of sudden cardiac death due to hypertrophic cardiomyopathy and idiopathic left ventricular hypertrophy.

Hypertrophic cardiomyopathy (HCM) is defined as left ventricular (LV) hypertrophy (LVH) in the absence of abnormal loading conditions and characterized by myocyte disarray at histology.1Elliott P.M. Anastasakis A. Borger M.A. et al.Authors/Task Force members2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy: the Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC).Eur Heart J. 2014; 35: 2733-2779Crossref PubMed Scopus (2686) Google Scholar After sudden cardiac death (SCD), the sole identification of significant LVH at autopsy may lead to an erroneous diagnosis of HCM. Data suggest that idiopathic LVH (ILVH) and HCM may be separate entities.2Finocchiaro G. Dhutia H. Gray B. et al.Diagnostic yield of hypertrophic cardiomyopathy in first-degree relatives of decedents with idiopathic left ventricular hypertrophy.Europace. 2020; 22: 632-642Crossref PubMed Scopus (12) Google Scholar We aimed to report the prevalence and nature of mitral valve (MV) abnormalities in SCD victims with postmortem findings consistent with HCM and ILVH. We hypothesized that MV abnormalities are more common in individuals with HCM and considered as additional macroscopic features to differentiate between these 2 entities.We reviewed 6860 consecutive cases of SCD referred to our specialist cardiac pathology center between 1994 and 2020. SCD was defined as death due to a cardiovascular cause within 12 hours of apparent well-being. All cases underwent detailed autopsy, and a minimum of 10 tissue blocks underwent histological analysis.3Basso C. Aguilera B. Banner J. et al.Guidelines for autopsy investigation of sudden cardiac death: 2017 update from the Association for European Cardiovascular Pathology.Virchows Arch. 2017; 471: 691-705Crossref PubMed Scopus (210) Google Scholar ILVH was defined as unexplained LVH (heart weight >500 g in males and >400 g in females) and LV wall thickness > 15 mm in the absence of myocardial disarray or secondary causes of LVH.2Finocchiaro G. Dhutia H. Gray B. et al.Diagnostic yield of hypertrophic cardiomyopathy in first-degree relatives of decedents with idiopathic left ventricular hypertrophy.Europace. 2020; 22: 632-642Crossref PubMed Scopus (12) Google Scholar The MV was examined for patency, circumference, thickening, nodularity, ballooning, bulging between cords, perforation, endocarditis, and the presence of impact lesions in the LV outflow tract and aortic outlet.Ethical approval was granted for this study (10/H0724/38).Of the total cases of SCD, 264 (4%) were due to HCM (mean age 41 ± 18 years; 78% males; LV maximal wall thickness 19 ± 6 mm) (Figure 1). Antemortem symptoms were reported in 44 cases (17%), and for the majority (n = 217 [82%]), the diagnosis of HCM was established at postmortem. Death was attributed to ILVH in 253 cases (3%; mean age 43 ± 16 years; 80% males; LV maximal wall thickness 18 ± 4 mm). MV abnormalities were found in 58 decedents with HCM (22%; mean age 38 ± 17 years; 72% males) and 13 decedents with ILVH (5%; mean age 55 ± 5 years; 77% males; P < .001). Myocardial fibrosis was observed in 162 cases of HCM (61%) and 99 cases of ILVH (39%) (P < .001).Of the 58 cases with HCM and MV abnormalities (22%), 15 (6%) had multiple MV abnormalities. These included impact lesions associated with thickening of the anterior MV leaflet (n = 39) and degenerative changes (n = 34) such as bulging and ballooning as well as thickening and nodularity. Decedents with HCM exhibiting MV abnormalities were younger than decedents with a normal MV (38 ± 17 years vs 45 ± 19 years; P = .08).Of the 253 decedents with ILVH, 13 (5%) exhibited MV abnormalities, which largely included degenerative changes (n = 12). Among decedents with HCM and ILVH exhibiting MV abnormalities, the former was significantly younger (38 ± 17 years vs 55 ± 15 years; P = .001).MV abnormalities were identified in 22% and 5% of decedents of SCD attributed to HCM and ILVH, respectively. Imaging studies, predominantly on cohorts with dynamic LV outflow tract obstruction, have reported mitral MV malformations in up to 70% of patients with HCM.4Kaple R.K. Murphy R.T. DiPaola L.M. et al.Mitral valve abnormalities in hypertrophic cardiomyopathy: echocardiographic features and surgical outcomes.Ann Thorac Surg. 2008; 85: 1527-1535Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar,5Maron M.S. Olivotto I. Harrigan C. et al.Mitral valve abnormalities identified by cardiovascular magnetic resonance represent a primary phenotypic expression of hypertrophic cardiomyopathy.Circulation. 2011; 124: 40-47Crossref PubMed Scopus (277) Google Scholar The lower prevalence of significant MV abnormalities in our cohort may be due to a lower proportion of obstructive cases, since most decedents did not have any preexisting cardiovascular symptoms and SCD was the first manifestation. Although LV outflow tract obstruction is regarded as a risk factor for fatal arrhythmias, an impact lesion was observed in 39 of 264 cases of HCM (15%), suggesting that systolic anterior motion of the MV and possible dynamic obstruction were relatively rare in this population. MV abnormalities were rare in ILVH and were found in older individuals, suggesting an underlying mechanism that is unrelated to sarcomeric disease. A limitation of our study is the absence of molecular autopsy findings. Furthermore, the inherent descriptive terminologies used when assessing the MV support a greater emphasis on the standardization and quantification of MV abnormalities as part of the autopsy, including the sub-MV apparatus and geometrical arrangements of papillary muscles, the presence of papillary muscle hypertrophy, and abnormal chordae tendineae arrangements. Hypertrophic cardiomyopathy (HCM) is defined as left ventricular (LV) hypertrophy (LVH) in the absence of abnormal loading conditions and characterized by myocyte disarray at histology.1Elliott P.M. Anastasakis A. Borger M.A. et al.Authors/Task Force members2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy: the Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC).Eur Heart J. 2014; 35: 2733-2779Crossref PubMed Scopus (2686) Google Scholar After sudden cardiac death (SCD), the sole identification of significant LVH at autopsy may lead to an erroneous diagnosis of HCM. Data suggest that idiopathic LVH (ILVH) and HCM may be separate entities.2Finocchiaro G. Dhutia H. Gray B. et al.Diagnostic yield of hypertrophic cardiomyopathy in first-degree relatives of decedents with idiopathic left ventricular hypertrophy.Europace. 2020; 22: 632-642Crossref PubMed Scopus (12) Google Scholar We aimed to report the prevalence and nature of mitral valve (MV) abnormalities in SCD victims with postmortem findings consistent with HCM and ILVH. We hypothesized that MV abnormalities are more common in individuals with HCM and considered as additional macroscopic features to differentiate between these 2 entities. We reviewed 6860 consecutive cases of SCD referred to our specialist cardiac pathology center between 1994 and 2020. SCD was defined as death due to a cardiovascular cause within 12 hours of apparent well-being. All cases underwent detailed autopsy, and a minimum of 10 tissue blocks underwent histological analysis.3Basso C. Aguilera B. Banner J. et al.Guidelines for autopsy investigation of sudden cardiac death: 2017 update from the Association for European Cardiovascular Pathology.Virchows Arch. 2017; 471: 691-705Crossref PubMed Scopus (210) Google Scholar ILVH was defined as unexplained LVH (heart weight >500 g in males and >400 g in females) and LV wall thickness > 15 mm in the absence of myocardial disarray or secondary causes of LVH.2Finocchiaro G. Dhutia H. Gray B. et al.Diagnostic yield of hypertrophic cardiomyopathy in first-degree relatives of decedents with idiopathic left ventricular hypertrophy.Europace. 2020; 22: 632-642Crossref PubMed Scopus (12) Google Scholar The MV was examined for patency, circumference, thickening, nodularity, ballooning, bulging between cords, perforation, endocarditis, and the presence of impact lesions in the LV outflow tract and aortic outlet. Ethical approval was granted for this study (10/H0724/38). Of the total cases of SCD, 264 (4%) were due to HCM (mean age 41 ± 18 years; 78% males; LV maximal wall thickness 19 ± 6 mm) (Figure 1). Antemortem symptoms were reported in 44 cases (17%), and for the majority (n = 217 [82%]), the diagnosis of HCM was established at postmortem. Death was attributed to ILVH in 253 cases (3%; mean age 43 ± 16 years; 80% males; LV maximal wall thickness 18 ± 4 mm). MV abnormalities were found in 58 decedents with HCM (22%; mean age 38 ± 17 years; 72% males) and 13 decedents with ILVH (5%; mean age 55 ± 5 years; 77% males; P < .001). Myocardial fibrosis was observed in 162 cases of HCM (61%) and 99 cases of ILVH (39%) (P < .001). Of the 58 cases with HCM and MV abnormalities (22%), 15 (6%) had multiple MV abnormalities. These included impact lesions associated with thickening of the anterior MV leaflet (n = 39) and degenerative changes (n = 34) such as bulging and ballooning as well as thickening and nodularity. Decedents with HCM exhibiting MV abnormalities were younger than decedents with a normal MV (38 ± 17 years vs 45 ± 19 years; P = .08). Of the 253 decedents with ILVH, 13 (5%) exhibited MV abnormalities, which largely included degenerative changes (n = 12). Among decedents with HCM and ILVH exhibiting MV abnormalities, the former was significantly younger (38 ± 17 years vs 55 ± 15 years; P = .001). MV abnormalities were identified in 22% and 5% of decedents of SCD attributed to HCM and ILVH, respectively. Imaging studies, predominantly on cohorts with dynamic LV outflow tract obstruction, have reported mitral MV malformations in up to 70% of patients with HCM.4Kaple R.K. Murphy R.T. DiPaola L.M. et al.Mitral valve abnormalities in hypertrophic cardiomyopathy: echocardiographic features and surgical outcomes.Ann Thorac Surg. 2008; 85: 1527-1535Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar,5Maron M.S. Olivotto I. Harrigan C. et al.Mitral valve abnormalities identified by cardiovascular magnetic resonance represent a primary phenotypic expression of hypertrophic cardiomyopathy.Circulation. 2011; 124: 40-47Crossref PubMed Scopus (277) Google Scholar The lower prevalence of significant MV abnormalities in our cohort may be due to a lower proportion of obstructive cases, since most decedents did not have any preexisting cardiovascular symptoms and SCD was the first manifestation. Although LV outflow tract obstruction is regarded as a risk factor for fatal arrhythmias, an impact lesion was observed in 39 of 264 cases of HCM (15%), suggesting that systolic anterior motion of the MV and possible dynamic obstruction were relatively rare in this population. MV abnormalities were rare in ILVH and were found in older individuals, suggesting an underlying mechanism that is unrelated to sarcomeric disease. A limitation of our study is the absence of molecular autopsy findings. Furthermore, the inherent descriptive terminologies used when assessing the MV support a greater emphasis on the standardization and quantification of MV abnormalities as part of the autopsy, including the sub-MV apparatus and geometrical arrangements of papillary muscles, the presence of papillary muscle hypertrophy, and abnormal chordae tendineae arrangements. We thank Cardiac Risk in the Young (CRY), which fund and support the CRY Cardiovascular Pathology Unit.

Tissue tracking of segmental strain as a predictor of provoked dynamic left ventricular outflow tract obstruction

BackgroundLeft ventricular outflow tract obstruction (LVOTO) is commonly observed in patients with hypertrophic cardiomyopathy (HCM) or left ventricular hypertrophy (LVH). Some patients develop LVOTO provoked by physical exertion, and hence termed dynamic LVOTO (DLVOTO). However, its precise prevalence and mechanism are still unclear. AimTwo-dimensional speckle tracking echocardiography (2D STE) seems to be helpful for the detection of early LV structural abnormalities. This study aimed to examine the possible role of segmental as well as global longitudinal strain in identifying DLVOTO non-HCM patients as detected by dobutamine stress echocardiography (DSE). Methods and resultsTwo hundred and fifty patients without structural heart disease had undergone conventional transthoracic echocardiography, 2D STE, and DSE. All patients with non-ischemic evidence were divided into two groups according to the DSE results; DLVOTO (+) and DLVOTO (−).Among 250 patients, 50 patients (36%) had shown DLVOTO after DSE (15 males, 35 females; mean age 55±7years). They were compared with 90 non -LVOTO obstruction patients (43 males, 47 females; mean age 57±6years). Based on multivariate logistic regression analysis, the independent predictors of provoked DLVOTO during DSE were resting basal septal longitudinal strain BS-LS average (p < 0.001), resting LA reservoir strain (p < 0.001), and systolic LVOT diameter (p = 0.03). Resting BS-LS average with cut-off - 17.5% was recognized as a critical indicator of DLVOTO, with sensitivity 78%, and specificity 95% (better than systolic LVOT diameter of sensitivity 76%, and specificity 15% and resting LA reservoir strain which showed poor AUC at ROC curve 0.007). ConclusionWe demonstrate that provoked LVOTO during DSE in non HCM symptomatic patients is directly correlated to resting regional LS, where the increased BS-LS of ≥ −17.5% was a key determinant of LVOT gradient provocation. Assessment of baseline BS-LS average might be a bedside simple tool for detection of patients with DLVOTO not able to do DSE.

Coincidence of Events Causing Paradoxical Hypotension in a Patient with an Intra-Aortic Balloon Pump.

The left ventricular outflow tract is a region of the left ventricle that lies between the anterior leaflet of the mitral valve and the ventricular septum. Dynamic left ventricular outflow tract obstruction (LVOTO) has classically been observed in patients with hypertrophic obstructive cardiomyopathy (HOCM) where it occurs secondary to asymmetric septal hypertrophy and systolic anterior motion (SAM) of the mitral valve. However, there are some instances that lead to hypercontractility of the myocardium, and with a combination of other physiological conditions, result in SAM of a mitral valve leaflet, leading to LVOTO in the absence of phenotype.We present such a case of an acute inferolateral wall myocardial infarction that was complicated by cardiogenic shock, requiring an intra-aortic balloon pump (IABP) and inotropic support which paradoxically provoked LVOTO. A reduction in IABP counterpulsation from 1:1 to 1:3 and the addition of intravenous fluids and a beta blocker resulted in significant improvement in blood pressure with rapid tapering of pressors.Inotropes and IABP, although helpful in cardiogenic shock, have the potential to induce or worsen the LVOTO, which can lead to a vicious cycle of worsening hypotension and increasing adrenergic drive that further deteriorates myocardial viability. Timely diagnosis with an echocardiogram and the withdrawal of inotropic and IABP support has the potential to improve haemodynamics and, thereby, outcome.LEARNING POINTSDynamic left ventricular outflow tract obstruction (LVOTO) should be one of the differentials in patients with cardiogenic shock, especially if it is refractory in the setting of an intra-aortic balloon pump.The diagnosis of LVOTO by echocardiography should result in immediate implementation of therapy to eliminate the factors that can potentially intensify the obstruction.

P168 A RARE CASE OF HYPERTROPHIC CARDIOMYOPATHY WITH HIGH RISK OF SUDDEN CARDIAC DEATH: WHAT CAN WE DO UNTIL MIECTOMY?

Abstract A 43–year–old Indian man with obstructive hypertrophic cardiomyopathy (HCMO) and a family history of sudden death presented with heart palpitations associated with chest discomfort and syncope during moderate physical activity despite beta–blocker therapy at maximum dose (New York Heart Association–NYHA III). Transthoracic echocardiography demonstrated ejection fraction 55% and ventricular septum (SIV) (23 mm) and posterior wall hypertrophy (12 mm). There was evidence of dynamic left ventricular outflow tract obstruction (maximum LVOT gradient 30 mmHg at baseline and 45 mmHg after Valsalva) and systolic anterior movement of the amterior mitral flap responsible of moderate regurgitation. It also showed a bicuspid aortic valve with fusion of the right and left cusps and mild regurgitation. ECG Holter showed sporadic supraventricular premature ectopic beats and abnormality of the ventricular repolarization that were accentuated during exercise. Exercise stress test showed 3 mm ST depression in V4–V5 leads. Cardiac magnetic resonance (CMR) and Cardio–CT confirmed HCMO diagnosis and showed a junctional origin of the coronaries, a bifurcated interventricular artery, coronaries free from significant stenosis, intramural late gadolinium enhancement (LGE) of the mid–ventricular SIV and sub–endocardium LGE of the basal SIV. The high HCM– Sudden Cardiac Death Risk score and the presence of LGE on CMR identified a high–risk status and prompt consideration for primary prevention automatic implantable cardioverter defibrillator (AICD) therapy. Thus, in order to treat major life–threatening ventricular arrhythmias, AICD was placed (ESC guidelines 2014 Class IIa). Invasive treatment is indicated for symptomatic patients, NYHA class III and IV refractory to optimized medication and who have gradients in the LVOT. Aortic transvalvular–myectomy is the procedure with the longest experience and considered the gold standard. However, in this case surgical treatment was temporarily postponed. So a sequential rhythm pacing with reduced A–V delay was set up in order to induce a left bundle branch block and a “paradoxical” movement of the SIV with reduction of LVOT gradient. After 2 weeks the LVOT gradient was 20 mmHg and the symptoms were improved. This case suggests the usefulness of a single device for the treatment of different aspects in HCMO waiting to undergo surgical treatment: prevention of sudden cardiac death and improvement of symptoms refractory to medical therapy.