Insights From Three-Dimensional Echocardiography Into the Mechanism of Functional Mitral Regurgitation

Otsuji, Yutaka; Handschumacher, Mark D.; Schwammenthal, Ehud; Jiang, Leng; Song, Jae‐Kwan; Guerrero, Jorge; Vlahakes, Gus J.; Levine, Robert A.

doi:10.1161/01.cir.96.6.1999

Cited by 534 publications

(417 citation statements)

References 56 publications

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“…A introdução da ecocardiografia foi oportuna e acrescentou dados importantes para a compree n s ã o d o s m e c a n i s m o s r e s p o n s á v e i s p e l a regurgitação valvar mitral observada na CMD, mas, de outra forma, limitou os estudos anatômicos, tão necessários para dar suporte às observações obtidas (4,5) .…”

Section: Introductionunclassified

Estudo comparativo do anel valvar mitral e do ventrículo esquerdo na cardiomiopatia dilatada

Hueb¹,

Jatene²,

Moreira³

et al. 2001

Rev Bras Cir Cardiovasc

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P M A, Mioto B M, Chabelmann R C, Oliveira S A -Estudo comparativo do anel valvar mitral e do ventrículo esquerdo na cardiomiopatia dilatada. Material e Métodos: Analisaram-se 68 corações humanos adultos, fixados, sendo 48 portadores de CMD de etiologia isquêmica ou idiopática, e 20 corações sem cardiopatia. Obteve-se imagens digitalizadas do perímetro do anel mitral, inserção da cúspide anterior e posterior e da porção fibrosa e muscular. Obteve-se também o perímetro interno do VE, distância do septo ao músculo papilar anterior e posterior, distância entre os músculos papilares, e extensão do septo interventricular.Resultados: A análise dos resultados demonstrou proporcionalidade, tanto da porção fibrosa (r 2 = 0.98), quanto da porção muscular (r 2 = 0.99) do anel em relação ao grau de dilatação da valva mitral. A regressão linear revelou que o perímetro de inserção das cúspides anterior (r 2 = 0.96) e posterior (r 2 =0.98) também guardam relação de proporcionalidade. Observou-se que a dilatação do VE ocorre de forma global e esférica em seus segmentos. Não se observou relação de proporcionalidade entre o grau de dilatação do anel mitral e do VE.Conclusão: Ao contrário do que se pensava, na CMD de etiologia isquêmica ou idiopática, a dilatação do anel mitral ocorre de forma proporcional e não apenas na sua porção posterior. Não é o grau de dilatação do VE que determina o grau de dilatação do anel mitral pois eles ocorrem de forma independente. Estas observações abrem novas perspectivas para as técnicas de correção da insuficiência valvar mitral na CMD.

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Section: Introductionunclassified

Estudo comparativo do anel valvar mitral e do ventrículo esquerdo na cardiomiopatia dilatada

Hueb¹,

Jatene²,

Moreira³

et al. 2001

Rev Bras Cir Cardiovasc

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“…For example, the contractility of the concerned PM decreases in the setting of an acute MI that affects the blood supply to the PM. In addition, MR is caused by coaptation failure of the mitral leaflets due to spatial imbalances in the mitral complex, including the PMs, in patients with a dilated heart or regional asynergy of the LV wall [2,3]. One study [8] recently proposed that PMs do not attach directly to the solid heart wall.…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, Otsuji et al [3] demonstrated that the main cause of ischemic MR is augmented leaflet tethering by outward displacement of the PM in patients with LV remodeling. Their results are consistent with a previous transesophageal 2-dimensional echocardiographic study [14].…”

Section: Discussionmentioning

confidence: 99%

“…Previously, it has been reported that a possible cause of mitral regurgitation (MR) is ischemia of the PM, which is called PM dysfunction [2], in patients with coronary artery disease. On the other hand, a recent study [3] demonstrated that the most important factor to cause ischemic MR is leaflet tethering by an outward displacement of the PM in patients with LV wall remodeling. Accordingly, PM function is vital to mitral valve competence.…”

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confidence: 98%

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Myocardial Strain Imaging is a Superior Method for Evaluating Papillry Muscle Contractility in Patients With Myocardial Infarction

et al. 2005

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The papillary muscles (PMs) of the left ventricle (LV) are part of the mitral apparatus. They act to hold the chordae tendineae taut by contracting in normal individuals, preventing the mitral leaflets from prolapsing into the left atrium during ventricular systole [1]. Previously, it has been reported that a possible cause of mitral regurgitation (MR) is ischemia of the PM, which is called PM dysfunction [2], in patients with coronary artery disease. On the other hand, a recent study [3] demonstrated that the most important factor to cause ischemic MR is leaflet tethering by an outward displacement of the PM in patients with LV wall remodeling. Accordingly, PM function is vital to mitral valve competence. However, quantitative assessment of PM function is difficult due to the functional and spatial complexity of the mitral apparatus. Recently, it has been recognized that strain imaging reflects differing aspects of myocardial deformation and is relatively independent of whole heart motion or tethering effects [4][5][6]. Therefore, this new modality would be expected to provide a more sensitive assessment of PM systolic function. The aim of the present study was to investigate PM contractility and how it is affected by the adja- Myocardial Strain Imaging is a Superior

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“…1,2 In this current issue of the European Heart JournalCardiovascular Imaging, members of these groups, using a related technology, have employed ultrasound to treat as well as to image the heart 3 in mitral regurgitation (MR) secondary to myocardial infarction (MI) that causes mitral valve (MV) leaflet tethering mediated by chordae to the displaced papillary muscles (PMs). 4 This is a condition for which a strong need is perceived for improved approaches. 5 Although there is evidence for adaptive MV growth in secondary MR, 6,7 this extra leaflet tissue is often insufficient to compensate adequately for mitral annular (MA) enlargement and chordal tethering.…”

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confidence: 99%

The power of ultrasound: treating secondary MR with sound waves

Dal‐Bianco¹,

Bartko²,

Levine³

2016

Eur Heart J Cardiovasc Imaging

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Innovations in physics and its applications often enable medical advances. Collaboration between physicists who developed a high-frame-rate ultrasound system and cardiovascular investigators has allowed non-invasive measurement of vascular and myocardial stiffness. 1,2 In this current issue of the European Heart JournalCardiovascular Imaging, members of these groups, using a related technology, have employed ultrasound to treat as well as to image the heart 3 in mitral regurgitation (MR) secondary to myocardial infarction (MI) that causes mitral valve (MV) leaflet tethering mediated by chordae to the displaced papillary muscles (PMs). 4 This is a condition for which a strong need is perceived for improved approaches. 5 Although there is evidence for adaptive MV growth in secondary MR,6,7 this extra leaflet tissue is often insufficient to compensate adequately for mitral annular (MA) enlargement and chordal tethering. 8 The MV leaflets thus become increasingly taut, being pulled by the annulus towards the base, and by chordae towards the left ventricular (LV) apex. The normally convex MV closing configuration towards left atrium becomes concave, and the anterior MV leaflet appears like a 'hockey stick' on Echo. 9 Once the necessary leaflet tissue redundancy for MV coaptation is exhausted, MR will develop, which will over time further advance annular remodelling and tethering by the collagen-based chordae 6,7,10 and therefore MR ( Figure 1A).Current medical and surgical and transcatheter repair therapies for secondary MR thus aim to reduce overall leaflet tethering to restore leaflet coaptation by addressing the impaired LV (optimal medical heart failure therapy, revascularization, resynchronization, potential myocardial regeneration) and the mitral annulus (restoration of normal sinus rhythm, annuloplasty). Not as clinically established, but shown to be safe and effective is to directly target the chordal apparatus by cutting secondary chordae attaching to the leaflet bodies to relieve their tethering and to restore a greater surface for leaflet coaptation 11,12 ( Figure 1B). Such chordal cutting reduces both MR and its associated LV remodelling 13 and has been successfully applied by several surgical groups. 14 -16 The pathological changes observed in chordae post-infarction 7 and the recent reported relation between secondary MR and chordal shortening, imposing additional restriction on the tethered leaflets, lend further support to the potential benefits of chordal cutting to relieve such MR. 17 The current paper reports a proof of concept for using pulsed cavitational focused ultrasound (histotripsy) to cut chordae non-invasively guided by real-time 3D echocardiography. 3 The authors show that secondary anterior chordae can be selectively cut in vitro and in vivo in the beating sheep heart with a high-energy Figure 1 (A) Functional/ischaemic MR: the PM is displaced posteriorly, laterally, and apically because of local LV dilatation and remodelling (arrows) caused by MI (shaded area). This LV wall-PM displace...

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Insights From Three-Dimensional Echocardiography Into the Mechanism of Functional Mitral Regurgitation

Abstract: LV dysfunction without dilatation fails to produce important MR. Functional MR relates strongly to changes in the 3D geometry of the mitral valve attachments at the PM and annular levels, with practical implications for approaches that would restore a more favorable configuration.

Cited by 534 publications

References 56 publications

Estudo comparativo do anel valvar mitral e do ventrículo esquerdo na cardiomiopatia dilatada

Estudo comparativo do anel valvar mitral e do ventrículo esquerdo na cardiomiopatia dilatada

Myocardial Strain Imaging is a Superior Method for Evaluating Papillry Muscle Contractility in Patients With Myocardial Infarction

The power of ultrasound: treating secondary MR with sound waves

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