Cardiac magnetic resonance imaging in the evaluation and management of
mitral valve prolapse.
Abstract
Mitral valve prolapse is a common valve disorder that usually has a
benign prognosis unless there is significant regurgitation or left
ventricular impairment. However, a subset of patients are at an
increased risk of ventricular arrhythmias and sudden cardiac death,
which has led to the recognition of ‘arrhythmic mitral valve prolapse’
as a clinical entity. Emerging risk factors include mitral annular
disjunction and myocardial fibrosis. While echocardiography remains the
primary method of evaluation, cardiac magnetic resonance has become
crucial in managing this condition. Cine-MR sequences provide accurate
characterization of prolapse and annular disjunction, assessment of
ventricular volumes and function, identification of early dysfunction
and remodeling, and quantitative assessment of mitral regurgitation when
integrated with flow imaging. However, the unique strength of magnetic
resonance lies in its ability to identify tissue changes. T1 mapping
sequences identify diffuse fibrosis, in turn related to early
ventricular dysfunction and remodeling. Late gadolinium enhancement
sequences detect replacement fibrosis, an independent risk factor for
ventricular arrhythmias and sudden cardiac death. There are consensus
documents and reviews on the use of cardiac magnetic resonance
specifically in arrhythmic mitral valve prolapse. However, in this
article, we propose an algorithm for the broader use of cardiac magnetic
resonance in managing this condition in various scenarios. Future
advancements may involve implementing techniques for tissue
characterization and flow analysis, such as 4D flow imaging, to identify
patients with ventricular dysfunction and remodeling, increased
arrhythmic risk, and more accurate grading of mitral regurgitation,
ultimately benefiting patient selection for surgical therapy.