Disjunção do anel mitral: modalidades diagnósticas, implicações clínicas e evolução prognóstica / Mitral annulus disjunction: diagnostic modalities, clinical implications, and prognostic progression

A disjunção do anel mitral (DAM) é uma inserção anormal da linha de flexão do anel mitral na parede atrial. O anel mostra uma separação (disjunção) entre a junção folheto posterior-parede atrial e a crista miocárdica ventricular esquerda.1 A DAM foi descrita pela primeira vez há mais de 30 anos em estudo de autópsia, estando relacionada com prolapso da valva mitral (PVM) em 92% dos casos.2 Desde então, foram realizados diversos estudos, sendo a prevalência de DAM em pacientes com PVM reportada de forma variável, podendo ou não estar associada à insuficiência mitral. O ecocardiograma transtorácico (ETT) faz parte da avaliação inicial do prolapso valvar mitral, permitindo o diagnóstico e a avaliação de complicações relacionadas. Com a evolução de novos métodos diagnósticos, a ressonância magnética cardíaca (RMC) e o ecocardiograma transesofágico (ETE) passaram a aprimorar a avaliação dessa patologia, bem como de sua extensão e localização. Contudo, as características fenotípicas do PVM que estão mais associadas a DAM permanecem incertas, sobretudo devido ao número limitado de pacientes, nos estudos clássicos sobre o tema. Portadores de DAM podem desenvolver sintomas relacionados a arritmias ventriculares, configurando a síndrome arrítmica da DAM (SDAM), podendo evoluir para morte súbita. Na literatura, os dados prognósticos ainda são conflitantes entre os diversos estudos acerca do tema, indo desde critérios claros de diagnóstico, o melhor método de imagem a ser aplicado, o tratamento e o prognóstico. Esta revisão descreve as características da DAM associada ou não ao prolapso valvar, auxiliando no diagnóstico e na conduta dessa importante patologia. (AU)

Mitral annulus disjunction (MAD) is an abnormal insertion of the flexion line of the mitral annulus into the atrial wall. The annulus presents a separation (disjunction) between the posterior leaflet­atrial wall junction and the left ventricular myocardial crest.1 MAD was first described more than 30 years ago in an autopsy study and is reportedly related to mitral valve prolapse (MVP) in 92% of cases.2 Since then, several studies have been conducted, and reports on the prevalence of MAD in patients with MVP have varied. Ultimately, it may or may not be associated with mitral regurgitation. Transthoracic echocardiography is part of initial MVP assessment, allowing its diagnosis and the assessment of related complications. As new diagnostic methods emerged, cardiac magnetic resonance imaging and transesophageal echocardiography improved the assessment of this pathology in terms of its diagnosis, extension, and location. However, the phenotypic characteristics of MVP that are more closely associated with MAD remain uncertain mainly due to the limited number of patients in classic studies on the subject. Patients with MAD may develop symptoms related to ventricular arrhythmias, configuring the MAD arrhythmic syndrome, which may progress to sudden death. The literature presents conflicting prognostic data among several studies on the subject from clear diagnostic criteria and best imaging method to be used to treatment and prognosis. This review describes MAD characteristics associated (or not) with valve prolapse to improve the diagnosis and management of this important pathology. (AU)

Real-time three-dimensional echocardiographic assessment of mitral valve: Is it really superior to 2D transesophageal echocardiography.

Aim of our study was to investigate the feasibility of use and possible additional value of real-time 3D transesophageal echocardiography (RT-3D-TEE) compared to conventional 2D-TEE in patients undergoing elective mitral valve repair. After ethical committee approval, patients were included in this prospective study. After induction of anesthesia, a comprehensive 2D-TEE examination was performed, followed with RT-3D-TEE. The intraoperative surgical finding was used as the gold standard for segmental analysis. Only such segments which were surgically corrected either by resection or insertion of artificial chords were judged pathologic. A total of 50 patients were included in this study; usable data were available from 42 of these patients . Based on the Carpentier classification, the pathology found was type I in 2 (5%) patients, type II in 39 (93%) patients and type IIIb in 1 (2%) patient. We found that 3D imaging of complex mitral disease involving multiple segments, when compared to 2D-TEE did not show any statistically significant difference.RT-3D-TEE did not show any major advantage when compared to conventional 2D-TEE for assessing mitral valve pathology, although further study in a larger population is required to establish the validity of this study.

Color Doppler echocardiographic assessment of Sorin mitral prosthetic valve.

Doppler echocardiographic characteristics of 57 normally functioning Sorin prosthetic valves (a tilting valve) in the mitral position were studied in the early postoperative period. The three valve sizes (in mm) studied were: 25 (n = 15), 27 (n = 32) and 29 (n = 10). The mean gradients (mmHg) and the valve area (Sq cm) calculated by pressure half time method) for the three valve sizes were 3.46 +/- 1.69 and 2.49 +/- 0.26; 3.46 +/- 1.25 and 2.57 +/- 0.44; and 3.2 +/- 1.23 and 2.55 +/- 0.41; respectively. There was no significant difference in gradients and valve area between the three sizes, variations in pressure half time and therefore the calculated valve area was large. Color Doppler evaluation revealed a bifid nonturbulent jet directed anteriorly towards the interventricular septum. 12 patients (20%) had mild valvar and 7 (12%) had paravalvar mitral regurgitation (mild in 5 and moderate in 2) without any associated prosthetic valve dysfunction. The paravalvar regurgitation persisted in all the 5 patients restudied at 5-12 months postoperatively. Sorin prosthetic valves have similar gradients and valve area when compared to other disc valves. The incidence of of paravalvar regurgitation was slightly higher in our series. The limitations of Doppler derived gradients and area of prosthetic valve are discussed.