Insuficiência Mitral Isquêmica 2 - by Fábio Soares

Dr. Luis Cláudio Lemos lembrou algo importante a ser reconhecido, nomeado e servir de orientação ao clínico e cirurgião. Abaixo, algumas definições de Insuficiência Mitral Isquêmica, segundo os grandes estudiosos do tema:

Ischaemic mitral regurgitation: mechanisms and diagnosis

Thomas H Marwick,1 Patrizio Lancellotti,2 Luc Pierard2

"Ischaemic mitral regurgitation (MR) is defined as MR caused by changes of left ventricular structure and function related ultimately to ischaemia. However, the acute manifestation of MR following infarction (which usually presents as a haemodynamic crisis) is related to rupture or stretching of the papillary muscle, and is normally categorised with complications of infarction. The term ischaemic MR is usually understood to relate to chronic MR, occurring .2 weeks after infarction and in the absence of structural mitral valve disease. In terms of pathogenesis, this should be considered a disease of abnormal left ventricular (LV) shape and function with a valvular manifestation."

Ischaemic mitral regurgitation: pathophysiology, outcomes and the conundrum of treatment

Luc A. Pie´rard1* and Blase A. Carabello2

"Appropriate systolic coaptation of the anterior and posterior mitral leaflets depends on normal anatomy and function of the different components of the mitral valve apparatus: annulus, leaflets, chordae, papillary muscles, and the left ventricular (LV) wall. Mitral regurgitation (MR) consists in systolic retrograde flow from the LV to the left atrium (LA) because of the lack of adequate coaptation of the leaflets and a pressure gradient between the two cavities. It is important to distinguish between primary MR due to organic disease of one or more components of the mitral valve apparatus and secondary MR which is not a valve disease, but represents the valvular consequences of a LV disease. Secondary MR is defined as functional MR, due to LV remodelling by idiopathic cardiomyopathy or coronary artery disease. In the latter clinical setting, secondary functional MR is called ischaemic MR."

Surgical Management of Ischemic Mitral Regurgitation

Mitesh V. Badiwala, MD; Subodh Verma, MD, PhD; Vivek Rao, MD, PhD

"The pathophysiology of IMR is complex. Coronary artery disease results in myocardial ischemia and culminates in an infarction. These acute and chronic insults set the stage for maladaptive left ventricular remodeling (with apical and posterior displacement of the papillary muscles), which in turn leads to altered left ventricular function and underlies the pathophysiology of IMR.13–18 Indeed, in as many as 19% of patients who experience an acute MI, IMR then develops.2,3 The remodeling of the left ventricle further results in subvalvular apparatus dysfunction with leaflet tethering caused by papillary muscle displacement and also results in loss of mitral annular contraction with annular dilatation. 13–18 As leaflet tethering occurs, the leaflets fail to coapt during systole and on echocardiographic examination are usually found to have restricted motion resulting in Carpentier type IIIb mitral regurgitation. As mitral annular dilatation secondary to left ventricular enlargement occurs, the leaflets also fail to coapt centrally, resulting in Carpentier type I mitral regurgitation. These changes ultimately lead to what is known as functional mitral regurgitation. Mitral regurgitation, in turn, leads to left

ventricular volume overload and exacerbates maladaptive left ventricular dilatation, completing the vicious circle of IMR and left ventricular remodeling. The majority of patients with IMR have functional MR with structurally normal mitral leaflets and subvalvular apparatus. The remaining patients with IMR have “structural” MR with either papillary muscle rupture or papillary muscle infarction with an intact papillary muscle, each requiring differing surgical repair techniques.5,19,20".

Mitral regurgitation
Maurice Enriquez-Sarano, Cary W Akins, Alec Vahanian

The ischaemic form of this disease rarely results from an organic mechanism (papillary-muscle rupture)25 and is rarely acute. Frequently, it is functional (structurally normal leafl ets) and chronic, epitomising left-ventricular disease that causes valvular dysfunction. Papillarymuscle dysfunction plays little part in the generation of functional mitral regurgitation, which is mostly caused by apical and inferior-papillary-muscle displacement due to ischaemic left-ventricular remodelling


How to manage ischaemic mitral regurgitation
Patrizio Lancellotti,1 Thomas Marwick,2 Luc A Pierard3


Ischaemic heart disease is becoming an increasingly frequent cause of ischaemic mitral regurgitation (IMR). Three different clinical entities of IMR, which deeply affect the clinical decision making, are distinguishable: the acute IMR complicating an acute myocardial infarction, the true IMR secondary to a transient ischaemic phenomenon, and the chronic functional IMR (FIMR). The incidence of the two first entities is low; the third is much more frequent.