Systolic Anterior Motion Research Articles

Abstract 4138007: Mechanisms of Mitral Regurgitation in Fabry Disease

Introduction: Fabry disease, caused by mutations in the gene encoding alpha-galactosidase A, results in the accumulation of globotriaosylceramide (Gb3), leading to systemic complications including cardiac involvement such as mitral regurgitation (MR). The aim of this study is to investigate the association between MR severity and mitral leaflet morphology in Fabry disease patients. A cohort of 38 symptomatic Fabry disease patients with moderate or significant MR was followed up. Mitral leaflet morphology was categorized as normal, fibrodegenerative changes, or leaflet thickening. MR severity varied, with the primary cause being leaflet restriction. Additionally, left ventricular outflow tract obstruction (LVOTO) and annular dilatation were observed. The study suggests that MR in Fabry disease is primarily due to leaflet restriction, either through degenerative changes or leaflet thickening. This study investigates the association between MR severity and mitral leaflet morphology in Fabry disease patients. Methods: A cohort of 38 symptomatic Fabry disease patients with moderate or significant MR was followed up. Echocardiographic assessments were conducted to determine MR severity and categorize mitral leaflet morphology. Statistical analyses were performed to evaluate associations between MR severity and leaflet morphology. Echocardiographic assessments of the mitral valve were conducted using a Vivid E95 Cardiac Ultrasound and meticulously analyzed using the EchoPAC TM and TOMTEC Imaging Systems. A crucial aspect of the examination involved measuring all components of the mitral valve and determining the requisite angles to evaluate each mechanism thoroughly. Results: Most patients exhibited leaflet restriction as the primary cause of MR, with varying degrees of severity. Mitral leaflet morphology was categorized as normal in 15,8%, fibrodegenerative changes were in 31,5% and leaflet thickening in 52,7%. In addition, outflow tract obstruction (LVOTO) was observed in 15,7% but without systolic anterior motion (SAM) and annular dilatation (dilatation of anteroposterior annulus more than 35 mm in systole) was present in 66%. Conclusion: The study suggests that MR in Fabry disease is primarily attributed to leaflet restriction, either due to degenerative changes or leaflet thickening. An additional, albeit not unexpected, finding not always considered is the presence of anteroposterior annular dilatation in some cases.

Abstract 4140118: Identification of Obstructive and Non-Obstructive Hypertrophic Cardiomyopathy Patients Using Natural Language Processing in a Large Integrated Healthcare System

Introduction: Accurately identifying and characterizing patients with hypertrophic cardiomyopathy (HCM) is critical for population management and care optimization. Research Question: To develop natural language processing (NLP) algorithms to identify and characterize obstructive (oHCM) and non-obstructive (nHCM) HCM patients directly from echocardiograms, and to compare with the presence or absence of HCM-related diagnosis codes. Methods: We developed and validated NLP algorithms to identify HCM from all adult (age≥18yrs) echocardiograms performed from 2010-2019 in Kaiser Permanente Northern CA (KPNC), capturing measures of any HCM, HCM subtype, hypertrophy subtype, septal and posterior LV wall thickness, resting and stress/Valsalva LVOT gradients, and systolic anterior motion. We developed a rules-based algorithm (following AHA/ACC criteria) to classify patients as having HCM, including oHCM or nHCM subtypes, and possible HCM (defined as wall thickness ≥2cm without other criteria meeting an HCM definition). We evaluated the presence of HCM-related ICD-9/10 diagnosis codes among patients classified as HCM/non-HCM from echocardiograms using NLP, and linked baseline demographics and clinical parameters from our integrated electronic medical record. Results: Among 472,405 adults with echocardiograms, we identified 2,892 patients with HCM based upon NLP-derived measures (all NLP measures achieved >95% positive predictive value and >95% negative predictive value), including 1,585 (55%) with oHCM, 1,145 (40%) with nHCM, and 162 (6%) which could not be classified (Figure). Among those 2,892 patients, 1,283 did not have any associated HCM ICD-9/10 diagnosis codes (Table). Among 469,513 patients with no identified HCM from NLP-based algorithms, HCM ICD-9/10 diagnosis codes existed in 1,567 patients (Table). We also identified 4,593 patients with possible HCM by NLP, only 4.5% of whom had an associated HCM code. Among confirmed HCM patients by NLP, oHCM patients were slightly older (66 vs 61 yrs), more likely female (53% vs 43%), had similar mean septal wall thickness (1.7cm vs 1.7cm), but were more likely to have a septal hypertrophy subtype (46% vs 28%) compared to nHCM patients. Conclusions: Echocardiogram-based NLP methods can improve the identification of and care for HCM patients. Many patients with possible HCM may be underdiagnosed, representing an opportunity for quality improvement.

Outcomes of Concomitant Mitral Intervention in Hypertrophic Obstructive Cardiomyopathy Surgery?: A Systematic Review and Meta-Analysis of Contemporary Evidence

The 2020 American Heart Association Guidelines advise not to perform mitral valve replacement (MVR) during septal myectomy (SM) to alleviate outflow obstruction. This study aims to review outcomes after concomitant mitral valve (MV) intervention versus SM alone. We conducted a comprehensive literature search across Embase, PubMed, and Scopus. Studies published up to June 15, 2024 were considered. We included studies that compared SM alone to concomitant MV repair or replacement. Subgroup analyses based on MV intervention were performed. Seven studies met our criteria, including 1 randomized and 6 observational studies. The total sample size was 17,565 patients with hypertrophic cardiomyopathy (11,849 SM, 2303 SM + MVR, and 3390 SM + MV repair). Patients who underwent SM + MV intervention had more pronounced preoperative MV regurgitation. SM + MVR was associated with significantly higher early mortality [risk ratio (RR): 2.85, 95% confidence interval (CI): 2.37–3.43, P < 0.00001, I² = 0%]. However, there was no difference in early mortality in patients who underwent SM + MV repair compared with SM alone (RR: 1.14, 95% CI: 0.88–1.49, P = 0.33, I² = 0%). Thirty days systolic anterior motion was significantly lower in patients who underwent SM + MV repair compared with SM alone (RR: 0.15, 95%CI: 0.05–0.45, P = 0.0007). Peak pressure left ventricular outflow tract gradient was significantly lower in the SM + MV repair group compared with SM alone (mean difference: −3.47, 95% CI: −5.55 to −1.39, P = 0.001). Current observational evidence suggests an increased risk of in-patient mortality in patients who underwent SM + MVR. SM + MV repair did not affect early mortality but was linked to improved outcomes. Future comprehensive and matched studies are warranted.

Abstract 4138268: The Use of Mavacamten for Management of Post TAVR Obstruction: A Novel Approach to Treatment

Background: Treatment of left ventricular outflow tract (LVOT) obstruction involves a combination of negative inotropic agents. However, these therapies have limitations which may result in insufficient control of symptoms, leading to more invasive options such as surgical septal myectomy or septal alcohol ablation. Mavacamten, a cardiac myosin inhibitor, is currently approved for the treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM). We present a case of a patient treated with mavacamten in addition to β-blockers (BB) for management of post-TAVR LVOT obstruction. Case: A 76 year old female with a past medical history of hypertension, severe aortic stenosis, and coronary artery disease underwent a Medtronic Evolut TAVR in March 2022. Her TTE post TAVR showed LVOT peak gradient greater than 100 mm Hg, LVEF 75% and severe eccentric mitral regurgitation secondary to systolic anterior motion (SAM) of the mitral valve (MV). After multidisciplinary discussion, the patient was discharged on maximally tolerated BB therapy. Follow up TTE showed persistent obstruction and gradients, so diltiazem was added to her regimen. Her subsequent TTE showed a peak LVOT > 100 mmHg at rest, and severe MR. Given persistent findings, she was started on mavacamten, continued on metoprolol, and tapered off of diltiazem. Her TTE two months after initiation of mavacamten revealed resolution of LVOT gradients, reduction of MR to mild and normal LV and TAVR function. She tolerated the therapy well and endorsed ongoing symptomatic improvement on subsequent follow up. Discussion: With the increasing use of TAVR therapy, there has been a corresponding rise in cases of post-TAVR obstruction that must be managed. As demonstrated by this case, management with BB therapy alone may be suboptimal. Although mavacamten is currently approved in patients with HCM, the obstruction in post-TAVR patients is functionally similar. Thus, this medication was trialed as a supplemental treatment in this patient and yielded positive results. This case highlights the potential benefit of extending use of mavacamten alongside β-blocker therapy for this patient population and suggests the need for future studies.

Abstract 4135212: An Overlap Between Takotsubo Cardiomyopathy and Hypertrophic Obstructive Cardiomyopathy Causing Dynamic Left Ventricular Outflow Tract Obstruction: A Unique Case Report

Background: Takotsubo cardiomyopathy (TC) can cause dynamic left ventricular outflow tract (LVOT) obstruction leading to cardiogenic shock. Due to differential wall-motion abnormalities, flow acceleration in the LVOT can lead to systolic anterior motion (SAM) of the mitral valve which worsens LVOT obstruction and leads to hemodynamic compromise. We present a case of overlap between TC and hypertrophic obstructive cardiomyopathy (HOCM) with worsening LVOT obstruction leading to cardiogenic shock. Case: A 76-year-old female presented with typical chest pain, nausea, and worsening shortness of breath. On examination, she was hypotensive and cold to touch. EKG showed T-wave inversions in lateral leads with elevated cardiac troponins. Coronary angiogram showed non-obstructive coronary artery disease, and right heart catheterization revealed elevated filling pressures. Transthoracic echocardiogram (TTE) showed septal hypertrophy and SAM of the mitral valve causing dynamic LVOT obstruction (Figure 1) and ejection fraction (EF) of 20%. TTE with contrast showed apical ballooning consistent with TC (Figure 2). Decision Making: Initially with diuresis, she became hypotensive so it was stopped and she received controlled intravenous fluids along with phenylephrine to reduce LVOT obstruction. Her blood pressure improved and she was started on low-dose metoprolol succinate along with ivabradine to reduce heart rate. She tolerated this therapy and hemodynamics stabilized. Conclusion: Cardiogenic shock can be a severe complication of TC. Early detection of LVOT obstruction in cardiogenic shock is important as traditional management strategies of increased inotropy and reduction of afterload can be fatal in these cases. The treatment strategy focuses on reducing the LVOT gradient and includes fluid administration to increase preload, beta-blockers to increase diastolic filling time, and vasopressors to raise afterload.

An Unexpected Finding in an Adolescent Rowing Athlete With Angina Pectoris. A Case Report.

Significant intraventricular gradient development during exercise is rare, usually occurring with left ventricular hypertrophy. The etiopathogenesis consists of the increase in nonobstructive physiological gradients; ventricular cavitary obliteration with consequent end-systolic obstruction; and midsystolic obstruction caused by systolic anterior movement of the mitral valve compromising flow. A correlation between intraventricular gradient development and various symptoms has been established. Chest pain is common in children and is a frequent reason for referral to pediatric cardiologists. Despite the benign nature of most pediatric chest pain, extensive and costly cardiac evaluation is common in these patients. In the case presented here, we describe an adolescent rowing athlete with excruciating effort angina only during upright exercise, which was replicated while performing an exercise stress echocardiography.

Effect of stereotactic body radiation therapy on left ventricular diastole function in symptomatic patients with hypertrophic obstructive cardiomyopathy

Abstract Background We applied stereotactic body radiotherapy (SBRT) for the first time in the treatment of patients with hypertrophic obstructive cardiomyopathy (HOCM), and significant improvements in symptoms and diastolic function were observed after treatment. Objectives To evaluate the impact of SBRT on cardiac structure, function, and clinical indicators in patients with HOCM. Methods This study included 12 drug-refractory symptomatic HOCM patients (6 who underwent SBRT and 6 who received pharmacological treatment alone) and conducted a retrospective analysis of their clinical data. Transthoracic echocardiography was used to assess various ultrasound parameters, including interventricular septal thickness, left ventricular outflow tract diameter, peak pressure gradient and diastolic function before treatment and at 1, 3, and 6 months after treatment. Additionally, assessments were made for symptoms; laboratory test results (NT-proBNP, cTnT, CK-mb, and CRP); 6-minute walk test results; New York Heart Association (NYHA) functional classification; and Kansas score before and 6 months after treatment. Results HOCM patients showed significant improvement in mitral valve systolic anterior motion after SBRT. Compared to that at baseline, the interventricular septum thickness gradually decreased at 1, 3, and 6 months after treatment (-8.8%, -8.0%, -14.4%, respectively) (P<0.05). Compared to those in the drug group, the left ventricular diastolic function and structural parameters, including the interventricular septum thickness (mean change from baseline of -3 mm [95% CI: -5.2 to -0.8 mm] and 1.3 mm [95% CI: 0.5 to 2.2 mm]; P<0.05), and the LA GLS (change of 2.1% [-0.03% to 4.2%] and -0.9% [-3.1% to 1.3%]; P<0.05), were significantly improved in HOCM patients at 6 months posttreatment. Similarly, the clinical indicators, including KCCQ, increased from baseline (61 (range, 47.3-70) to 84 (range, 70-89.5) at 6 months posttreatment (P<0.05), and the 6-minute walk test score increased from 187 meters (range, 50-370) to 401 meters (range, 280-540) (P<0.05). Conclusion SBRT significantly improved left ventricular diastolic function and reduced interventricular septum thickness in HOCM patients. Symptoms, exercise capacity and clinical indicators improved after SBRT in HOCM patients.

Exploring the effects of mavacamten through hemodynamic force analysis in patients with obstructive hypertrophic cardiomyopathy

Abstract Introduction Mavacamten is a first-in-class allosteric myosin inhibitor effective in relieving left ventricular (LV) outflow tract obstruction in patients with obstructive hypertrophic cardiomyopathy (oHCM). To date, however, its effect on cardiac mechanics is still unclear. Hemodynamic force (HDF) analysis represents the fluid dynamics correlate of deformation imaging, showing a greater sensitivity in detecting early mechanical abnormalities or response to treatment [1]. Purpose To explore the in vivo effect of mavacamten on cardiac mechanics in patients with HCM after a 3 year-treatment, using HDF analysis. Methods LV HDF analysis was performed in 6 patients with oHCM (representing a cohort of the MAVA-LTE study) at baseline and after 3 years of treatment. Apical 4-, 2-, and 3-chamber echocardiographic views were analysed using a dedicated and sofisticated software. Base-apex forces (where positive deflections represent a force directed from the apex to the base of LV, whilst negative ones are directed toward the LV apex) were assessed in terms of timing indexed to cardiac cycle duration. HDF curves from the 6 patients treated with macavamten were compared to those obtained from oHCM patients (n=20), non-obstructive HCM (noHCM) patients (n=20), and healthy controls (n=22). Results Figure 1 shows a different pattern of transition between diastole and systole in HCM patients compared to controls. Specifically, HCM patients exhibited an earlier onset of the systolic phase, expressed as a fusion of late diastolic deceleration and systolic thrust. This was numerically represented as a decrease in diastolic-systolic transition time, which is 0.22 [0.20-0.24] for oHCM, 0.23 [0.21-0.25] for noHCM and 0.26 [0.26-0.30] for controls (p ≤0.001 for control vs oHCM, p ≤0.01 for control vs noHCM). Additionally, HCM patients showed an increased rate of force generation. The time to systolic peak (i.e., time interval from the onset of systole to the maximum force) was reduced in HCM patients compared to controls, and was shorter in oHCM than in noHCM patients (0.13 [0.11-0.15] vs 0.16 [0.14-0.17], p ≤0.01), thus reflecting an increased clinotropism in HCM. After 3 years of mavacamten treatment, the diastolic-systolic transition time and the time to systolic peak returned to a level similar to that of healthy controls (0.30 [0.27-0.30] in mavacamten group vs 0.26 [0.26-0.30], p >0.05, and 0.21 [0.20-0.22] vs 0.19[0.17-0.20], p=0.04, respectively) (Figure 2). Conclusion HDF analysis reveals that mavacamten affects the duration of transition from diastole to systole and prolongs time from the onset to the peak in systole. These findings may explain the removal of the mechanical coupling substrate responsible for the systolic anterior movement of mitralic leaflets and the subsequent resolution of LV outflow tract obstruction by mavacamten.Distribution of time parameters

Ring only repair of bileaflet mitral valve prolapse with mitral regurgitation: Insights from computational modeling

This study evaluates the efficacy of annuloplasty repair as a standalone procedure for treating bileaflet mitral valve prolapse with mitral regurgitation (MR). Various flexible ring bands for MR of different severities were compared to assess their biomechanical impact and treatment outcomes. Computational beating heart models, based on the Living Heart Human Model, were utilized to simulate annuloplasty repairs. Repairs using bands of varying lengths were modeled on moderate and severe MR cases, considering bileaflet mitral valve prolapse. Key parameters, including regurgitant orifice area (ROA), prolapse severity, coaptation length, leaflet position, and deformation, were computed to compare conditions before and after implantation. Annuloplasty repairs effectively reduced the ROA in both moderate and severe MR cases, achieving complete sealing in selective instances. Additionally, annuloplasty repair corrected bileaflet prolapse, with prolapse severity decreasing as the annular size increased. Successful coaptation was indicated by the expansion of each leaflet’s contact area distribution and percentage in contact with the opposing leaflet. The risk of systolic anterior motion, that may obstruct the left ventricular outflow tract, was minimized, as the anterior leaflet was directed towards the posterior position. In conclusion, annuloplasty repair alone can effectively treat MR when an appropriate band length is selected. It facilitates a significant reduction in ROA, correction of bileaflet prolapse, and improvement in leaflet coaptation. These findings have important clinical implications, potentially offering a less complex surgical treatment avenue and reducing complications in the management of MR.

Clinical Outcomes of Concomitant Secondary Chordal Cutting to Surgical Myectomy in HOCM.

In patients who underwent surgical septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM), additional mitral valve repair may offer additional benefits in terms of further reducing left ventricle outflow tract (LVOT) gradients, systolic anterior motion (SAM) and mitral regurgitation (MR). We performed a systematic review of the literature to evaluate the evidence of surgical myectomy with additional secondary chordal cutting in patients with HOCM. A systematic literature search in MEDLINE and EMBASE was performed until April 2024. The primary outcome studied was postoperative echocardiographic LVOT-gradient. A random effects meta-analysis of means was performed for the primary outcome. The secondary outcomes studied were postoperative residual MR-grade, 30-day new permanent pacemaker implantation, and in-hospital mortality. From 1911 unique publications, a total of 6 articles fulfilled the inclusion criteria and comprised 471 patients with a pooled mean preoperative resting LVOT gradient of 84 mmHg (95% CI: 76-91). The postoperative pooled mean LVOT-gradient was 11 mmHg (95% CI: 10 - 12) with a low heterogeneity (I2 = 44%). The residual LVOT gradient exceeding 30 mmHg was present in 9 (1%) patients. MR-grade 3 or 4 at hospital discharge was present in 7 (1%) patients. The 30-day new permanent pacemaker implantation rate was 7% and the in-hospital mortality was 0.4%. This systematic review and meta-analysis demonstrate that combining surgical septal myectomy with secondary chordal cutting can be performed safely and effectively eliminate LVOT obstruction in HOCM patients. Further studies are needed to determine the additive effectiveness of additional secondary chordal cuttings.

Heart of Stone: Cardiogenic Shock from Myocardial and Mitral Valve Calcification with Systolic Anterior Motion (SAM) Defect after Valve Replacement in a Patient on Chronic Hemodialysis (CHD)

Heart of Stone: Cardiogenic Shock from Myocardial and Mitral Valve Calcification with Systolic Anterior Motion (SAM) Defect after Valve Replacement in a Patient on Chronic Hemodialysis (CHD)

Septal Myectomy for Isolated Midventricular Obstruction After Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy

BackgroundAlcohol septal ablation is an alternative to surgical myectomy for septal reduction in obstructive hypertrophic cardiomyopathy, particularly in high-risk surgical patients. However, alcohol septal ablation can sometimes result in residual left ventricular obstruction, typically in the subaortic area and, much more rarely, in the midventricular region. MethodsThis report presents 3 unique cases of isolated midventricular obstruction without systolic anterior motion that required surgical myectomy after alcohol septal ablation. ResultsThree patients presented with persistent or recurrent symptoms of left ventricular outflow obstruction after alcohol septal ablation. Surgical myectomy, performed through a transapical approach alone or in combination with a transaortic approach, successfully reduced intracavitary gradients and septal thickness in all 3 patients. One patient underwent cardiac transplantation 2 years after septal myectomy due to diastolic heart failure without obstruction. ConclusionsThis case series highlights concerns about the use of alcohol septal ablation for patients with long-segment subaortic obstruction and midventricular involvement, suggesting that surgical myectomy may be a more suitable treatment option for this anatomic subtype.

Usefulness of intraoperative color three-dimensional transesophageal echocardiography for detecting treatable residual mitral regurgitation immediately after mitral valve repair

BackgroundResidual mitral regurgitation (MR) immediately after mitral valve (MV) repair is a risk factor for late reintervention. This study aimed to determine the feasibility of color 3-dimensional intraoperative transesophageal echocardiography (3D-IOTEE) for clarifying the mechanism of residual MR and its impact on the conversion rate to MV replacement (MVR). MethodsAmong 767 patients who underwent MV repair at our institute, 92 consecutive patients in whom an immediate second cardiopulmonary bypass (CPB) was performed due to MV repair for residual MR were evaluated. The patients were divided into the re-repair group [i.e. those in whom repair required additional procedures, n = 77 (83.7 %)] and the MVR group [i.e. patients who underwent MVR alone, n = 15 (16.3 %)]. All patients underwent 3D-IOTEE to evaluate the mechanisms of residual MR. The pathomechanisms were classified into the following five categories: Category 1, inter-scallop malcoaptation; Category 2, suture dehiscence; Category 3, prolapse; Category 4, systolic anterior motion of the MV; and Category 5, tethering. Clinical background and outcomes were compared between the two groups based on the five categories. ResultsThe rate of MVR conversion by etiology of residual MR after the first MV repair was 68.8 % (n = 11/16) in Category 1; 0 % (n = 0/22) in Category 2; 2.4 % (n = 1/41) in Category 3; 20 % (n = 2/10) in Category 4; and 33.3 % (n = 1/3) in Category 5. Among the 63 patients with Category 2 and 3 etiologies, 62 patients had complete MV re-repair with additional procedures [Category 2, 100 % (n = 22/22); Category 3, 97.6 % (n = 40/41)]. Meanwhile, MVR was performed owing to difficulty in MV repair after the second CPB in 11/16 patients (68.8 %) with Category 1 etiology. ConclusionsIn the assessment of MR, 3D-IOTEE is useful for lesion localization and determining the origin and severity of MR, which are key factors in selecting the optimal surgical approach in patients undergoing re-repair.

Longitudinal assessment of systolic anterior motion of the mitral valve in cats with hypertrophic cardiomyopathy.

The proportion of cats with hypertrophic cardiomyopathy (HCM) that lose systolic anterior motion of the mitral valve (SAM) in the long term is unknown. Cats with HCM will lose SAM in the long term. Loss of SAM will be associated with greater age, longer scan-interval, and alteredleft ventricular (LV) dimensions. Sixty unsedated cats with HCM, not receiving beta blockers or pimobendan. A retrospective cohort study from 2 referral centers. Cats were eligible if they had been diagnosed with HCM and had a repeat echocardiogram ≥1 year later. Clinical and echocardiographic data of the left heart variables were collected. Thirty-eight cats had SAM at the initial scan. After a median follow-up time of 2.1 years (range: 1.0-5.9), 7 cats had lost SAM (18%) and 5 cats (23%) gained SAM. On follow-up, cats with SAM at the initial scan had a larger left atrium (P = .037), lower left atrial fractional shortening (P = .014), greater LV internal diameter in end-systole (P = .002), and lower LV fractional shortening (P < .001). Four cats with SAM developed congestive heart failure. There were no new cases of congestive heart failure or change in left heart variables in cats without SAM at the initial scan. The gain or loss of SAM was not associated with age or time between scans. Similar proportions of cats gained or lost SAM. Cats with SAM at baseline had more evidence of disease progression than cats without SAM.

Prevalence of cardiomyopathy and cardiac mortality in a colony of non-purebred cats in New Zealand

ABSTRACT Aims To evaluate the prevalence of subclinical cardiomyopathy and cardiac mortality in a research colony of non-purebred cats, established as a model of the wider cat population in New Zealand. Methods All apparently healthy, compliant, non-pregnant, non-neonatal cats in the colony at the Centre for Feline Nutrition (Massey University, Palmerston North, NZ) underwent physical examination and echocardiography using a 4.4–6.2-MHz probe by a board-certified veterinary cardiologist. Cardiac phenotype was classified following current guidelines. Hypertrophic cardiomyopathy (HCM) phenotype was defined as an end-diastolic left ventricular wall thickness ≥ 6 mm. Colony mortality data from February 2012 to February 2022 was reviewed to determine cardiac mortality. Results Cats (n = 132; 65 females and 67 males) included in the study had a median age of 4.1 (IQR 3.0–8.0) years. Thirty-two (24%) cats had a heart murmur, and three (2%) cats had an arrhythmia. Echocardiography revealed heart disease in 24 (18.2%) cats, including 23 with an HCM phenotype and one with a restrictive cardiomyopathy phenotype. Of the cats with the HCM phenotype, 3/23 had systemic hypertension or hyperthyroidism or both, and these cats were excluded from the final diagnosis of HCM (20/132; 15.2 (95% CI = 9.5–22.4)%). Between 2012 and 2022, 168 colony cats died, with 132 undergoing post-mortem examination. Heart disease was considered the cause of death in 7/132 (5.3%; 95% CI = 2.2–10.6%) cats; five had HCM, one a congenital heart defect, and one myocarditis. The overall prevalence of death related to HCM in the colony during this period was 3.8% (95% CI = 1.2–8.6%). Three cats with HCM and the cat with a congenital heart defect died unexpectedly without prior clinical signs, while congestive heart failure was observed prior to death in two cats with HCM and the cat with myocarditis. Additionally, 30/132 (22.7%) cats had cardiac abnormalities but died for non-cardiac reasons. Conclusions Subclinical cardiomyopathy, specifically HCM, was common in cats in the colony. Given that the colony originated as a convenience selection of non-purebred cats in New Zealand, the true prevalence of HCM in the wider New Zealand population is likely to fall within the 95% CI (9.5–22%). The proportion of deaths of colony cats due to HCM was lower (3.8%) supporting the conclusion that subclinical cardiomyopathy may not progress to clinical disease causing death. Clinical relevance Veterinarians should be aware of the high prevalence of subclinical HCM when treating cats. Abbreviations CAM: Systolic anterior motion of the chordae tendineae; CFN: Centre for Feline Nutrition; HCM: Hypertrophic cardiomyopathy; LA/Ao: Left atrial to aortic ratio; LV FS: Left ventricular fractional shortening; LVIDd: Left ventricular internal diameters in end-diastole; LVIDs: Left ventricular internal diameter in end-systole; LVWT: Max Maximum left ventricular wall thickness; SAM: Systolic anterior motion of the mitral valve; 2D: Two-dimensional

Three-Tesla Magnetic Resonance Imaging Characteristics of Hypertrophic Cardiomyopathy: A Comparison with Several Echocardiography Parameters.

Hypertrophic cardiomyopathy (HCM) is a primary cardiac disorder characterized by myocardial hypertrophy without increased afterload. This study set out to describe the cardiac magnetic resonance (CMR) imaging characteristics of HCM and to evaluate correlations of selected CMR parameters with echocardiography. This cross-sectional study enrolled 46 patients diagnosed at the Vietnam Heart Institute with HCM and underwent CMR at the Radiology Center, Bach Mai Hospital, from July 2021 to September 2022. A left ventricular outflow tract (LVOT)/aortic valve (AO) diameter ratio of ≥0.38 on CMR was consistent with an LVOT pressure gradient (PG) of <30 mmHg on echocardiography. The LVOT diameter and the LVOT/AO diameter ratio differed significantly between obstructive and non-obstructive HCM. The predominant phenotypes were diffuse asymmetric HCM (32.6%) and septal HCM (37%), followed by apical HCM (6.5%). Most late gadolinium enhancement (LGE) lesions were observed in the mid-wall of the hypertrophic segments. The mean LGE mass was significantly higher in the obstructive group than in the non-obstructive HCM group (p < 0.05). A strong negative correlation (r = -0.66) was found between the LVOT/AO diameter ratio on the CMR and the LVOT PG via echocardiography. Moreover, echocardiography detected morphologic risk factors for sudden cardiac death (SCD) in 80.4% of patients, whereas the corresponding proportion detected by CMR was 91.3%. Patients with systolic anterior motion (SAM) had a risk for a LVOT/AO diameter ratio <0.38, which was 5.7 times the risk observed in their counterparts without SAM. The LVOT/AO diameter ratio detected by CMR is a precise index for classifying hemodynamic HCM groups. CMR was better than echocardiography for SCD risk stratification.

Silent Threats of the Heart: A Case Series and Narrative Review on Suicide Left Ventricle Post-Aortic Valve Replacement in Patients with Dynamic LVOT Obstruction and Aortic Stenosis.

Aortic stenosis (AS) is the most prevalent valvular heart disease in Europe and North America, with transcatheter aortic valve implantation (TAVI) revolutionizing its management. Hypertrophic left ventricle (HLV) frequently coexists with AS, complicating treatment due to the associated risk of left ventricular outflow tract (LVOT) obstruction, heart failure, and sudden death. A rare but severe post-aortic valve replacement (AVR) complication, termed "suicide left ventricle" (SLV), has emerged, necessitating further study. This report synthesizes current literature on SLV, its pathophysiology, and management strategies, alongside four patient case studies. The patients aged 79-87 years, underwent AVR for symptomatic AS with HLV. Post-AVR, all experienced severe complications, including dynamicLVOT gradients, systolic anterior motion (SAM) of the mitral valve, and severe hypotension, leading to death in two cases. One patient survived following surgical aortic valve replacement (SAVR) with surgical myectomy. One patient survived after TAVI. These cases highlight the critical importance of multidisciplinary Heart Team evaluations and personalized treatment plans in managing SLV. Despite advancements in AVR, SLV remains a complex, life-threatening condition, requiring an exhaustive and multifaceted approach for optimal patient outcomes. This report offers valuable insights into SLV occurrence and management from a clinical perspective.

An innovative minimally invasive approach for hypertrophic obstructive cardiomyopathy: Transaortic septal myectomy via right infra-axillary incision

ObjectiveTo assess the short-term outcomes of the transaortic modified Morrow procedure when performed via a minimally invasive right infra-axillary incision. MethodsWe conducted a retrospective observational study at a single center of patients diagnosed with hypertrophic obstructive cardiomyopathy from September 2021 to July 2023. ResultsThe cohort comprised 148 patients (mean age 47.2 ± 15.0 years; 59.5% male). A majority (137/148, 92.6%) presented with systolic anterior motion. All procedures were successfully completed through a 4- to 5-cm right infra-axillary incision, without requiring conversion to sternotomy. Transthoracic echocardiography demonstrated a significant reduction in maximum septal thickness from 20.9 ± 5.0 mm to 14.4 ± 3.5 mm (95% confidence interval, 5.66-7.28; P < .001), and in left ventricular outflow tract gradient from 85.1 ± 50.9 mm Hg to 11.7 ± 10.3 mm Hg (95% confidence interval, 65.1-81.6; P < .001). The systolic anterior motion phenomenon was completely eliminated, with no severe mitral regurgitation was observed postoperatively. No iatrogenic ventricular septal defects occurred. One hundred twenty-four (83.8%) patients were extubated in the operating room. Eight (5.4%) patients received permanent pacemaker implantation. Unfortunately, 1 patient (0.7%) died of an intraoperative subarachnoid hemorrhage. ConclusionsThe transaortic modified Morrow procedure, performed through a minimally invasive right infra-axillary incision, shows favorable short-term outcomes.

Posterior Leaflet Mitral Valve Repair with Septal Myectomy For Hypertrophic Cardiomyopathy

Posterior Leaflet Mitral Valve Repair with Septal Myectomy For Hypertrophic Cardiomyopathy

Three-dimensional anatomic features of the mitral valve that predict systolic anterior motion occurring during dobutamine stress echocardiography.

Left ventricular outflow tract obstruction related to systolic anterior motion (SAM) of the mitral valve is a common complication of dobutamine stress echocardiography (DSE). However, the mechanisms underlying SAM have not been fully characterized. The objective of the present study was to use three-dimensional echocardiography to identify anatomic features of the mitral valve that predispose to SAM during DSE. We retrospectively evaluated consecutive patients included prospectively in our database and who had undergone 3D echocardiography (including an assessment of the mitral valve) before DSE. Patients who had developed SAM during DSE (the SAM+ group) were matched 2:3 with patients who did not (the SAM- group). One hundred patients were included (mean age: 67±10). Compared with SAM- patients (n=60), SAM+ patients (n=40) had a lower mitral annular area, a smaller perimeter, and a smaller diameter (p<.01 for all, except the anteroposterior diameter). The SAM+ group had also a narrower mitral-aortic angle (126±12° vs. 139±11° in the SAM- group; p<.01) and a higher posterior mitral leaflet length (1.4±.27cm vs. 1.25±.29, respectively; p<.01). Furthermore, the mitral annulus was more spherical, more flexible, and more dynamic in SAM+ patients than in SAM- patients (p<.05 for all). In a multivariate analysis of anatomic variables, the mitral-aortic angle, the mitral annular area, and posterior leaflet length were independent predictors of SAM (p ≤ .01 for all). In a multivariate analysis of standard echo and hemodynamic variables, the presence of wall motion abnormalities at rest (p<.01) was an independent predictor of SAM. SAM during DSE is multifactorial. In addition to the pharmacologic effects of dobutamine on the myocardium, 3D echocardiographic features of the mitral valve (a smaller mitral annulus, a narrower mitral-aortic angle, and a longer posterior leaflet) appear to predispose to SAM.