Project description:A 67-year-old woman with exertional dyspnea was referred to our hospital. Transthoracic echocardiography revealed severe mitral regurgitation and significant left ventricular (LV) outflow tract obstruction due to prominent systolic anterior motion (SAM) of the mitral valve without LV hypertrophy. Oral bisoprolol remarkably attenuated SAM. Two- or three-dimensional echocardiographic analysis demonstrated the elongation of anterior and posterior mitral leaflets and interventricular septum (IVS) bulging due to narrow aorto-mitral angle. In the present case, elongation of mitral leaflet and hyperkinetic motion of left ventricle, and IVS bulging due to narrow aorto-mitral angle possibly play important roles in the development of SAM. <Learning objective: Mitral regurgitation due to systolic anterior motion (SAM) can be dramatically improved by beta-blocker therapy. Although the precise mechanism of SAM has not been fully elucidated, structural changes of mitral apparatus (elongation of mitral leaflet and papillary muscle displacement), and structural or functional features of left ventricle (hyperkinetic motion, small ventricle, interventricular septum bulging, narrow aorto-mitral angle) possibly play important roles in the development of SAM.>.
Project description:ObjectivesThe systolic anterior motion (SAM) of mitral valves occurs at a certain rate despite the introduction of several preventive procedures. The purpose of this study was to investigate its mechanism by analysing the change in mitral valve morphology associated with operative procedures.MethodsComponents of mitral valves were measured before and after operative procedures by transoesophageal echocardiography in 179 patients who underwent mitral valve repair. Comparisons were made between 15 patients with SAM (SAM group) and 164 patients without SAM (non-SAM group).ResultsMorphological analysis in all the studied patients revealed that operative procedures shifted the coaptation point towards the left ventricular outflow tract by 6.9 mm and increased the extra portion of anterior leaflet that extended beyond the coaptation point by 5.4 mm. These changes were enhanced in the SAM group. Intergroup comparison revealed that there were no differences in the preoperative mitral valve morphologies between the two groups. After operative procedures, however, the SAM group showed smaller annular diameter and smaller coapted anterior/posterior length ratio compared with the non-SAM group.ConclusionsThe results of this study show that operative procedures might modify the morphology of mitral valves susceptible to developing SAM. Postoperative smaller annular diameter and anterior shift of coaptation point were considered to contribute to the development of SAM.
Project description:A patient with myxomatous mitral valve prolapse underwent mitral mitral valve repair due to severe symptomatic mitral regurgitation. Preoperative echocardiography demonstrated systolic anterior motion of the mitral valve. This finding disappeared once spontaneous chordal rupture occurred, resulting in a flail posterior mitral leaflet. As the patient was considered at high risk of developing post-repair SAM, he was operated on using surgical techniques aimed at lowering the risk of this complication. Despite this, post-repair SAM did develop and could only be eliminated by a surgical edge-to-edge (Alfieri) repair.
Project description:Background and objectiveThe 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.MethodsA 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 findingsThe 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.ConclusionsRecent 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.
Project description:A 30-year-old man presented with symptomatic severe chronic aortic regurgitation, first-degree atrioventricular block, and near-continuous mitral regurgitation. Surgical intervention, including aortic root replacement and mitral valve repair, was successful, highlighting the close relationship between valvular diseases and emphasizing the importance of comprehensive assessment for optimal management.
Project description:BackgroundThird heart sounds in cats frequently are associated with hypertrophic cardiomyopathy (HCM) but their exact characterization and timing within the cardiac cycle remains unknown.ObjectivesCharacterize third heart sounds in cats by phonocardiography and test the ability of 3 observers with different levels of experience and training to recognize third systolic heart sounds in cats.AnimalsFifty client-owned cats of different breeds presented for heart screening.MethodsCats were prospectively assessed using an electronic stethoscope (with digital recording) and then underwent full conventional echocardiographic examination. Audio recordings were blindly assessed in a random order by 3 observers: the cardiologist who collected clinical data, as well as a trained and an untrained junior veterinarian. Cohen's kappa coefficients were calculated to quantify agreement between the opinion of each observer and the echocardiography results (considered the gold standard).ResultsTwenty cats had a third systolic sound on phonocardiography and an obstructive HCM phenotype with systolic anterior motion of the mitral valve (SAM) on echocardiography. Agreement with echocardiography was very good for the experienced cardiologist, substantial for the trained junior veterinarian, and poor for the untrained junior veterinarian (kappa of 0.92, 0,64, and 0.08, respectively).Conclusions and clinical importanceWe describe here a new auscultatory abnormality in cats with obstructive HCM. It could help a trained non-cardiologist veterinarian in suspecting obstructive HCM in cats based on auscultation only.