Razširjenost in klinični pomen razmaka mitralnega obroča ocenjenega z magnetnoresonančnim slikanjem srca

Zugwitz, Daša (author), Prokšelj, Katja (mentor), Nijveldt, Robin (comentor)

Uvod Razmak mitralnega obroča (ang. mitral annular disjunction – MAD) je razmak med prirastiščem zadnjega lističa mitralne zaklopke in bazo proste stene levega prekata. Domneva se, da bi MAD lahko igral vlogo pri nastanku malignih ventrikularnih motenj srčnega ritma in nenadne srčne smrti. Prevalenca MAD v splošni populaciji ni znana, prav tako nimamo podatkov o klinični pomembnosti MAD. Metode V opazovalni presečni študiji smo analizirali posnetke 2.646 belcev, ki so bili med aprilom 2014 in avgustom 2015 vključeni v slikovni del študije UK Biobank. Dolžina MAD je bila merjena na štirih točkah mitralnega obroča v standardnih CMR presekih po dolgi osi. V preseku treh votlin je bila ocenjena in izmerjena prisotnost MVP in ali je prisotno zvračanje inferolateralne stene levega prekata. Pojav ventrikularnih motenj ritma je bil analiziran z uporabo sistematiziranih ključnikov znotraj UK Biobank baze, ki vključujejo tudi anamnestično poročanje o bolezni, uporabo zdravil za zdravljenje motenj srčnega ritma in diagnoze zabeležene tekom hospitalizacij. Rezultati V raziskavi smo analizirali 2.607 CMR preiskav. MAD je bil prisoten pri 1.990 (76%) preiskovancih, večinoma ob sprednji in ob spodnji in sprednji steni levega prekata. Preiskovanci z MAD na eni od teh ali obeh lokacijah so sestavljali 61,6% celotnega vzorca in 80,7% vseh preiskovancev z zabeleženim MAD. MAD ob inferolateralni steni, ki je v literaturi in kliniki prepoznan kot klinično pomemben, je bil prisoten pri 134 preiskovancih (5%). Verjetnost prisotnosti MVP je bila pomembno višja pri preiskovancih z MAD nad inferolateralno in spodnjo steno levega prekata. Našli smo statistično pomembno povezavo med MAD, MVP in sistoličnim zvračanjem. Sistolično zvračanje smo zabeležili pri 51 preiskovancih, od teh pa jih več kot polovica (53%) ni imela inferolnega MAD, 18% preiskovancev z inferolateralnim MAD imelo tudi sistolično zvračanje, med tem ko je bilo sistolično zvračanje zabeleženo le pri 1% ljudi brez inferolateralnega MAD. Zaradi premajhnega števila zabeleženih motenj srčnega ritma pri preiskovancih v vzorcu nismo mogli dokazati povezave med MAD in ventrikularnimi motnjami srčnega ritma. Zaključek S študijo smo pokazali, da je MAD pogosta najdba na CMR. Dokazali smo povezavo med MAD in MVP ter MAD, MVP in sistoličnim zvračanjem mitralnega obroča. Kljub trenutnim trendom, ki nakazujejo potrebo po dodatni diagnostiki pri pacientih z MAD, pogostost najdbe v splošni populaciji nakazuje, da v odsotnosti zabeleženih motenj srčnega ritma ali simptomov dodatna diagnostika ni smotrna.

• Language: Slovenian
• Keywords: Razmak obroča mitralne zaklopke, prolaps mitalne zaklopke
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2026
• PID: 20.500.12556/RUL-182972
• Publication date in RUL: 30.05.2026

Secondary language

• Language: English
• Title: Prevalence and clinical impact of mitral valve disjunction assessed using cardiac magnetic resonance imaging

Abstract

Background Mitral annular disjunction (MAD) is the separation between the posterior mitral valve leaflet hinge point and left ventricular myocardium. It is thought to be associated with malignant ventricular arrhythmias and sudden cardiac death. The prevalence of MAD in the general population and its clinical significance remain unknown. Methods In this cross-sectional observational study, we assessed the images of 2,646 Caucasian subjects enrolled in the UK Biobank imaging study between April 2014 and August 2015. Longitudinal MAD distance was measured at 4 points around the mitral annulus. Additionally, three-chamber long axis images were assessed for the presence of MVP or billowing, and for the presence of systolic curling of the inferolateral left ventricular wall. Ventricular arrhythmias were determined using a combination of UK Biobank fields, including self-reported illness, medication use, and inpatient diagnoses. Results Among the 2,607 included patients, MAD was observed in 1,990 (76%) cases. MAD was most commonly observed at the inferior and anterior LV wall. Subjects with MAD at either or both locations made up 61.6% of the total studied population and 80.7% of all subjects with MAD. Inferolateral MAD, which is reported in literature as clinically important, was found in 134 (5%) cases. There was a significantly higher likelihood of MVP in subjects with MAD at the inferolateral and inferior wall. There is evidence to support significant positive associations between MAD, MVP, and systolic curling. While systolic curling was seen in only 51 patients, of which more than half (53%) did not have inferolateral MAD, 18% of subjects with inferolateral MAD also have systolic curling, compared to only 1% of subjects with no inferolateral MAD. Due to the low number of reported ventricular arrhythmias in the study population, no significant correlation between MAD and cardiac arrhythmias could be made. Conclusions This large-scale study on subjects from the UK Biobank cohort shows that MAD is a common finding on cardiac magnetic resonance (CMR). Presence of inferolateral MAD, however, is rare. While current literature suggests that MAD, when identified, warrants further investigation, our data provide no evidence to support further arrhythmic work-up in coincidentally identified MAD.

• Keywords: Mitral annular disjunction, mitral valve prolapse