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The Journal of Thoracic and... Jan 2022To categorize and assess the functional significance of anomalous papillary muscles in patients undergoing surgical management of obstructive hypertrophic cardiomyopathy.
OBJECTIVES
To categorize and assess the functional significance of anomalous papillary muscles in patients undergoing surgical management of obstructive hypertrophic cardiomyopathy.
METHODS
We reviewed the records of operations for obstructive hypertrophic cardiomyopathy and identified 73 patients with an anomalous papillary muscle. Anomalous papillary muscles inserting directly into the body of the anterior mitral valve leaflet were classified as type I, those with both direct insertion into the body of the leaflet and attachment to the free edge of the anterior leaflet were categorized as type II, and anomalous papillary muscles inserting into the free edge of the anterior leaflet were grouped as type III. Additionally, we investigated detection rates by preoperative transthoracic echocardiography, intraoperative transesophageal echocardiography, and cardiac magnetic resonance imaging.
RESULTS
The mean age of patients was 51.9 ± 12.3 years, and 49.3% were male. The anomalous papillary muscle was classified as type I in 31.5% of patients, type II in 35.6%, and type III in 32.9%. Only type I and type II anomalous papillary muscles contributed to left ventricular outflow tract obstruction. The anomalous papillary muscle was detected on preoperative transthoracic echocardiography in 11% of patients and by intraoperative transesophageal echocardiography in 27.4% of patients. No anomalous papillary muscles were identified on cardiac magnetic resonance imaging. All patients underwent septal myectomy with or without (n = 34) associated excision of the anomalous papillary muscle. Excision of the papillary muscles was more common in patients with type I and II (76.4% and 80.8%, respectively) when compared with type III (4.2%). Ten patients underwent mitral valve repair, and 1 patient had mitral valve replacement.
CONCLUSIONS
Papillary muscle abnormalities are important findings in patients with obstructive hypertrophic cardiomyopathy but are not identified preoperatively in the majority of patients. Recognition of anomalous papillary muscles intraoperatively and understanding of the morphologic subtypes are critical to adequate gradient relief and preservation of mitral valve function. The optimum approach involves a transaortic extended septal myectomy associated with the resection of the anomalous papillary muscles in patients with type I and II anatomy.
Topics: Cardiac Surgical Procedures; Cardiomyopathy, Hypertrophic; Echocardiography, Transesophageal; Female; Heart Septum; Humans; Intraoperative Complications; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Mitral Valve; Mitral Valve Annuloplasty; Outcome and Process Assessment, Health Care; Papillary Muscles; Postoperative Complications; Preoperative Care; United States
PubMed: 32414597
DOI: 10.1016/j.jtcvs.2020.04.007 -
Current Cardiology Reviews 2023Mitral valve prolapse (MVP) is the most frequent valvulopathy in the general population, with usually a favourable prognosis. Although it can be associated with some...
Mitral valve prolapse (MVP) is the most frequent valvulopathy in the general population, with usually a favourable prognosis. Although it can be associated with some complications, ventricular arrhythmias (VA) and sudden cardiac death (SCD) are the most worrying. The estimated risk of SCD in MVP is between 0.2% to 1.9% per year, including MVP patients with and without severe mitral regurgitation (MR). The association between SCD and MVP is expressed by a phenotype called "malignant MVP" characterized by transthoracic echocardiography (TTE) findings such as bileaflet myxomatous prolapse and mitral annulus disjunction (MAD), ECG findings such as repolarization abnormalities, complex ventricular arrhythmias (c-VAs) and LV fibrosis of papillary muscles (PMs) and inferobasal wall visualized by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Therefore, attention is raised for patients with "arrhythmic MVP" characterized from an ECG point of view by frequent premature ventricular contractions (PVCs) arising from one or both PMs as well as by T-wave inversion in the inferolateral leads. In athletes, SCD is the most frequent medical cause of death and in young subjects (< 35 years) usually is due to electrical mechanism affecting who has a silent cardiovascular disease and are not considered per se a cause of increased mortality. In MVP, SCD was reported to happen during sports activity or immediately after and valve prolapse was the only pathological aspect detected. The aim of the present paper is to explore the association between SCD and MVP in athletes, focusing attention on ECG, TTE in particular, and CMR findings that could help to identify subjects at high risk for complex arrhythmias and eventually SCD. In addition, it is also examined if sports activity might predispose patients with MVP to develop major arrhythmias.
Topics: Humans; Mitral Valve Prolapse; Contrast Media; Gadolinium; Death, Sudden, Cardiac; Mitral Valve; Ventricular Premature Complexes; Prolapse; Athletes
PubMed: 36545732
DOI: 10.2174/1573403X19666221220163431 -
Current Treatment Options in... May 2022The purpose of this review is to explore the prevalence and risk factors for a malignant phenotype in mitral valve prolapse (MVP) characterized by life-threatening...
PURPOSE OF REVIEW
The purpose of this review is to explore the prevalence and risk factors for a malignant phenotype in mitral valve prolapse (MVP) characterized by life-threatening ventricular arrhythmias and sudden cardiac arrest and death (SCD), including mechanistic and pathophysiologic findings and mechanism-based potential therapies.
RECENT FINDINGS
A malignant phenotype in MVP characterized by life-threatening arrhythmias has long been recognized, although MVP is often benign. Efforts to identify this malignant phenotype have revealed potential risk factors for SCD that include elongated, myxomatous leaflets, ECG changes and complex ventricular ectopy. More recently, malignant MVP has been associated with myocardial fibrosis in the papillary muscles and inferobasal left ventricular wall. This localization suggests a central role of prolapse-induced mechanical forces on the myocardium in creating an arrhythmogenic substrate and triggering life-threatening arrhythmias. This mechanism for fibrosis is also consistent with imaging evidence of prolapse-induced mechanical changes in the papillary muscles and inferobasal left ventricular wall. Currently, no therapy to prevent SCD in malignant MVP has been established and limited clinical data are available. Mechanistic information and prospective study have the potential to identify patients at risk of SCD and preventive strategies.
SUMMARY
Malignant MVP relates to unique properties and mechanical abnormalities in the mitral valve apparatus and adjacent myocardium. Increased understanding of disease mechanisms and determinants of arrhythmias is needed to establish effective therapies.
PubMed: 35784809
DOI: 10.1007/s11936-022-00956-3 -
Circulation. Cardiovascular Imaging Aug 2016Arrhythmic mitral valve prolapse (MVP) is characterized by myxomatous leaflets and left ventricular (LV) fibrosis of papillary muscles and inferobasal wall. We searched...
BACKGROUND
Arrhythmic mitral valve prolapse (MVP) is characterized by myxomatous leaflets and left ventricular (LV) fibrosis of papillary muscles and inferobasal wall. We searched for morphofunctional abnormalities of the mitral valve that could explain a regional mechanical myocardial stretch.
METHODS AND RESULTS
Thirty-six (27 female patients; median age: 44 years) arrhythmic MVP patients with LV late gadolinium enhancement on cardiac magnetic resonance and no or trivial mitral regurgitation, and 16 (6 female patients; median age: 40 years) MVP patients without LV late gadolinium enhancement were investigated by morphofunctional cardiac magnetic resonance. Mitral annulus disjunction (median: 4.8 versus 1.8 mm; P<0.001), end-systolic mitral annular diameters (median: 41.2 versus 31.5; P=0.004) and end-diastolic mitral annular diameters (median: 35.5 versus 31.5; P=0.042), prevalence of posterior systolic curling (34 [94%] versus 3 [19%]; P<0.001), and basal to mid LV wall thickness ratio >1.5 (22 [61%] versus 4 [25%]; P=0.016) were higher in MVP patients with late gadolinium enhancement than in those without. A linear correlation was found between mitral annulus disjunction and curling (R=0.85). A higher prevalence of auscultatory midsystolic click (26 [72%] versus 6 [38%]; P=0.018) was also noted. Histology of the mitral annulus showed a longer mitral annulus disjunction in 50 sudden death patients with MVP and LV fibrosis than in 20 patients without MVP (median: 3 versus 1.5 mm; P<0.001).
CONCLUSIONS
Mitral annulus disjunction is a constant feature of arrhythmic MVP with LV fibrosis. The excessive mobility of the leaflets caused by posterior systolic curling accounts for a mechanical stretch of the inferobasal wall and papillary muscles, eventually leading to myocardial hypertrophy and scarring. These mitral annulus abnormalities, together with auscultatory midsystolic click, may identify MVP patients who would need arrhythmic risk stratification.
Topics: Adult; Arrhythmias, Cardiac; Biopsy; Contrast Media; Death, Sudden, Cardiac; Echocardiography; Electrocardiography, Ambulatory; Female; Fibrosis; Heart Ventricles; Humans; Hypertrophy, Left Ventricular; Linear Models; Magnetic Resonance Imaging; Male; Middle Aged; Mitral Valve; Mitral Valve Prolapse; Papillary Muscles; Prognosis; Risk Factors; Ventricular Function, Left; Young Adult
PubMed: 27516479
DOI: 10.1161/CIRCIMAGING.116.005030 -
Journal of Thoracic Disease Jun 2017Ischemic mitral regurgitation (IMR) is a complex disorder occurring after a myocardial infarction and affecting both the mitral valvular and subvalvular apparati.... (Review)
Review
Ischemic mitral regurgitation (IMR) is a complex disorder occurring after a myocardial infarction and affecting both the mitral valvular and subvalvular apparati. Several abnormalities can be detected in IMR as annular dilatation, leaflet tethering with impaired coaptation and papillary muscle (PM) displacement along a posterior, apical or lateral vectors. Treatments available include, beside myocardial revascularization, mitral-valve repair or chordal-sparing replacement. Repair is normally achieved downsizing the mitral valve annulus with a rigid or semirigid ring. However, considering the involvement of the subvalvular apparatus, techniques addressing the PM have been developed. The rationale at the basis of this strategy relies in the possibility to reduce the interpapillary muscle distance restoring the geometry of the left ventricle (LV) and ultimately resolving the leaflet tethering at the basis of IMR. Subvalvular apparatus surgical approaches include the papillary muscle approximation (PMA), surgical relocation and PM sling. Improved outcomes in terms of postoperative positive left ventricular remodeling and recurrence of mitral regurgitation have been reported, but more investigations are required to confirm the efficacy of subvalvular apparatus surgery. Application of finite element analysis to improve preoperative and intraoperative planning and achieve a correct and durable repair by means of subvalvular surgery is an exciting new avenue in IMR research.
PubMed: 28740718
DOI: 10.21037/jtd.2017.06.98 -
BioRxiv : the Preprint Server For... Aug 2023Mitral valve (MV) disease including myxomatous degeneration is the most common form of valvular heart disease with an age-dependent frequency. Genetic evidence indicates...
BACKGROUND
Mitral valve (MV) disease including myxomatous degeneration is the most common form of valvular heart disease with an age-dependent frequency. Genetic evidence indicates mutations of the transcription factor are associated with MV defects, including mitral valve regurgitation. In this study, we sought to determine whether murine and its closely related factor, , are required in valvular endothelial cells (VECs) for the maintenance of MV leaflets, including VEC junctions and the stratified trilaminar extracellular matrix (ECM).
METHODS
Adult mice carrying tamoxifen-inducible, endothelial cell (EC)-specific, compound mutations (i.e., EC--DKO mice) were used to study the function of and in the maintenance of mitral valves. The EC-mutations of were induced at 7 - 8 weeks of age by tamoxifen treatment, and abnormalities in the MVs of EC--DKO mice were assessed via whole-mount immunostaining, immunohistochemistry, and Movat pentachrome/Masson's Trichrome staining.
RESULTS
EC-deletions of and in mice resulted in abnormally extended and thicker mitral valves by causing defects in regulation of ECM organization with increased proteoglycan and decreased collagen. Notably, reticular adherens junctions were found in VECs of control MV leaflets, and these reticular structures were severely disrupted in EC- mutant mice. PROX1, a key regulator in a subset of VECs on the fibrosa side of MVs, was downregulated in EC- mutant VECs. Furthermore, we determined the precise location of lymphatic vessels in murine MVs, and these lymphatic vessels were aberrantly expanded in EC- mutant mitral valves.
CONCLUSIONS
Our results indicate that and are required for maintaining the integrity of the MV, including VEC junctions, ECM organization, and lymphatic vessels to prevent myxomatous mitral valve degeneration.
PubMed: 37693499
DOI: 10.1101/2023.08.30.555455 -
Journal of Thoracic Disease Jun 2022The prevalence of hypertrophic cardiomyopathy (HCM) is estimated to be 1 in 200 to 500 individuals, with systolic anterior motion (SAM) of the mitral valve (MV) and left... (Review)
Review
BACKGROUND AND OBJECTIVE
The prevalence of hypertrophic cardiomyopathy (HCM) is estimated to be 1 in 200 to 500 individuals, with systolic anterior motion (SAM) of the mitral valve (MV) and left ventricular outflow tract (LVOT) obstruction present in 60% to 70%. In this narrative review, we aim to elucidate the pathophysiology of SAM-septal contact and LVOT obstruction in HCM by presenting a detailed review on the anatomy of the MV apparatus in HCM, examining the various existing theories pertaining to the SAM phenomenon as supported by cardiac imaging, and providing a critical assessment of management strategies for SAM in HCM.
METHODS
A literature review was performed using PubMed, EMBASE, Ovid, and the Cochrane Library, of all scientific articles published through December 2021. A focus was placed on descriptive studies, reports correlating echocardiographic findings with pathologic diagnosis, and outcomes studies.
KEY CONTENT AND FINDINGS
The pathophysiology of SAM involves the complex interplay between HCM morphology, MV apparatus anatomic abnormalities, and labile hemodynamic derangements. Echocardiography and cardiac magnetic resonance (CMR) vector flow mapping have identified drag forces, as opposed to the "Venturi effect", as the main hydraulic forces responsible for SAM. The degree of mitral regurgitation with SAM is variable, and its severity is correlated with degree of LVOT obstruction and outcomes. First line therapy for the amelioration of SAM and LVOT obstruction is medical therapy with beta-blockers, non-dihydropyridine calcium-channel blockers, and disopyramide, in conjunction with lifestyle modifications. In refractory cases septal reduction therapy is performed, which may be combined with a 'resect-plicate-release' procedure, anterior mitral leaflet extension, surgical edge-to-edge MV repair, anterior mitral leaflet retention plasty, or secondary chordal cutting.
CONCLUSIONS
Recent scientific advances in the field of HCM have allowed for a maturation of our understanding of the SAM phenomenon. Cardiac imaging plays a critical role in its diagnosis, treatment, and surveillance, and in our ability to apply the appropriate therapeutic regimens. The increasing prevalence of HCM places an emphasis on continued basic and clinical research to further improve outcomes for this challenging population.
PubMed: 35813751
DOI: 10.21037/jtd-22-182 -
The Canadian Journal of Cardiology Sep 2014The role of exercise testing and stress imaging in the management of patients with valvular heart disease (VHD) is reviewed in this article. The American College of... (Review)
Review
The role of exercise testing and stress imaging in the management of patients with valvular heart disease (VHD) is reviewed in this article. The American College of Cardiology/American Heart Association and the European Society of Cardiology/European Association of Cardiothoracic Surgery have recently put emphasis on the role of exercise testing to clarify symptom status and the use of stress imaging to assess the dynamic component of valvular abnormalities and unmask subclinical myocardial dysfunction that could be missed at rest. Recent studies have demonstrated the incremental prognostic value of exercise echocardiography for asymptomatic patients with severe aortic stenosis, moderate-severe mitral stenosis, and severe primary mitral regurgitation. In patients with low-flow, low-gradient aortic stenosis, dobutamine stress echocardiography is recommended to differentiate true severe from pseudosevere aortic stenosis. Data on the prognostic value of stress echocardiography in aortic regurgitation and functional mitral regurgitation are less robust. Data are sparse on the use of stress imaging in right-sided VHD, however recent studies using stress cardiovascular magnetic resonance imaging offer some prognostic information. Although the strongest recommendations for surgical treatment continue to be based on symptom status and resting left ventricular repercussions, stress imaging can be useful to optimize risk stratification and timing of surgery in VHD. Randomized clinical trials are required to confirm that clinical decision-making based on stress imaging can lead to improved outcomes.
Topics: Aortic Valve Insufficiency; Aortic Valve Stenosis; Blood Pressure; Decision Making; Dobutamine; Echocardiography, Stress; Electrocardiography; Exercise Test; Heart Valve Diseases; Humans; Mitral Valve Insufficiency; Mitral Valve Stenosis; Prognosis; Pulmonary Artery; Ventricular Function, Left
PubMed: 25151284
DOI: 10.1016/j.cjca.2014.03.013 -
Swiss Medical Weekly Nov 2018BACKGROUND The term “predisposition” is used as an indication of antimicrobial prophylaxis to prevent infective endocarditis and as a criterion for diagnosing... (Review)
Review
BACKGROUND The term “predisposition” is used as an indication of antimicrobial prophylaxis to prevent infective endocarditis and as a criterion for diagnosing infective endocarditis according to the modified Duke criteria. The criterion for diagnosing infective endocarditis in native valves is not well defined. OBJECTIVES To identify conditions that increase the risk for infective endocarditis in native valves, for the diagnosis of infective endocarditis according to the modified Duke criteria. In parallel, we compared the results with the year of patient inclusion for each study and echocardiographic techniques. RESULTS Our systematic review included 207 studies published from January 1970 to August 2015. Studies that focused on mitral valve prolapse (112 studies), prior infective endocarditis (96) and bicuspid aortic valve (78) provided the most data. However, only six (5.3%), three (3.1%) and one (1.3%) of these studies, respectively, used analytical statistical methods. Three (2.7%), two (2.1%) and one (1.3%), respectively, were graded as good quality studies. Odds ratios (ORs) for developing infective endocarditis were 3.5–8.2 for mitral valve prolapse, and 2.2 and 2.8 for prior infective endocarditis. The hazard ratio for developing infective endocarditis was 6.3 for bicuspid aortic valve. The mean prevalence proportion of infective endocarditis in patients with these three heart conditions were 8.5% (mitral valve prolapse), 8.3% (prior infective endocarditis) and 8.8% (bicuspid aortic valve). The proportions of publications prior to the publication of the modified Duke criteria were 81.8, 75.6 and 74%, respectively. Evolution of the imaging method and echocardiographic technique was estimated to be considerable for mitral valve prolapse. The literature review on aortic valve stenosis (46 studies), mitral valve insufficiency (41) and aortic valve insufficiency (39) provided two analytical studies for aortic stenosis. One study was graded as good quality and reported a hazard ratio 4.9. The mean prevalence of these heart conditions in patients with infective endocarditis were 7.3, 19.9 and 10.2%, respectively. The proportions of publications prior to the publication of the modified Duke criteria were 78, 75.6 and 79.5%, respectively. The evolution of both the echocardiographic technique and the categorisation of valve disease severity was considerable for all three entities. CONCLUSIONS The evidence for native valve heart conditions predisposing to infective endocarditis is mainly based on studies with only descriptive statistics published prior to the release of the modified Duke criteria. Mitral valve prolapse, prior infective endocarditis and bicuspid aortic valve are frequently cited as predisposing heart conditions for infective endocarditis. The evolution in echocardiographic techniques over the past decades and its influence on diagnosis was considerable for mitral valve prolapse, aortic stenosis, mitral insufficiency and aortic insufficiency.
Topics: Aortic Valve; Aortic Valve Insufficiency; Bicuspid Aortic Valve Disease; Echocardiography; Endocarditis; Guidelines as Topic; Heart Valve Diseases; Humans; Mitral Valve Prolapse; Risk Factors
PubMed: 30440064
DOI: 10.4414/smw.2018.14675 -
Journal of Clinical Medicine Jul 2023The aim of the present review is to highlight the strengths and limitations of echocardiographic parameters and scores employed to predict favorable outcome in complex... (Review)
Review
Echocardiographic Parameters for Risk Prediction in Borderline Right Ventricle: Review with Special Emphasis on Pulmonary Atresia with Intact Ventricular Septum and Critical Pulmonary Stenosis.
The aim of the present review is to highlight the strengths and limitations of echocardiographic parameters and scores employed to predict favorable outcome in complex congenital heart diseases (CHDs) with borderline right ventricle (RV), with a focus on pulmonary atresia with intact ventricular septum and critical pulmonary stenosis (PAIVS/CPS). A systematic search in the National Library of Medicine using Medical Subject Headings and free-text terms including echocardiography, CHD, and scores, was performed. The search was refined by adding keywords "PAIVS/CPS", Ebstein's anomaly, and unbalanced atrioventricular septal defect with left dominance. A total of 22 studies were selected for final analysis; 12 of them were focused on parameters to predict biventricular repair (BVR)/pulmonary blood flow augmentation in PAIVS/CPS. All of these studies presented numerical (the limited sample size) and methodological limitations (retrospective design, poor definition of inclusion/exclusion criteria, variability in the definition of outcomes, differences in adopted surgical and interventional strategies). There was heterogeneity in the echocardiographic parameters employed and cut-off values proposed, with difficultly in establishing which one should be recommended. Easy scores such as TV/MV (tricuspid/mitral valve) and RV/LV (right/left ventricle) ratios were proven to have a good prognostic accuracy; however, the data were very limited (only two studies with <40 subjects). In larger studies, RV end-diastolic area and a higher degree of tricuspid regurgitation were also proven as accurate predictors of successful BVR. These measures, however, may be either operator and/or load/pressure dependent. TV Z-scores have been proposed by several authors, but old and heterogenous nomograms sources have been employed, thus producing discordant results. In summary, we provide a review of the currently available echocardiographic parameters for risk prediction in CHDs with a diminutive RV that may serve as a guide for use in clinical practice.
PubMed: 37510714
DOI: 10.3390/jcm12144599