Teaching Case

A 50 years-old female underwent clinical evaluation for thoracic pain, tachycardia and discomfort. She had dyslipidemia and recent SARS-CoV-2 infection.

Echocardiogram showed septal and apical hypokinesia, mild reduction of ejection fraction and mild mitral valve regurgitation.

A Computed Tomography Coronary Angiography (CCTA) and a Cardiac Magnetic Resonance (CMR) were performed.

Coronary Computed Tomography Angiography demonstrated fibro-fatty plaque determining mild-stenosis of left descending artery (LAD) ostium, followed by superficial intramyocardial bridge (Fig 1a). Furthermore, fibro-fatty plaque was observed on right coronary artery (RCA) ostium causing moderate reduction of calibre (Fig 1b).

CMR confirmed left ventricle apex hypokinesia and showed mitral annulus disjunction (MAD), mitral valvular prolapse (MVP) of both leaflets (Fig 2a and 2b). Moreover, CMR showed focal area of late gadolinium enhancement (LGE) in an anterolateral auxiliary papillary muscle and in the posteromedial papillary muscle (Fig 3b). 

Based on this finding, the patient underwent dynamic ECG-Holter monitoring to better evaluate possible arrhythmias caused by these structural and tissue findings.

Papillary muscles are myocardial structures that play a key role in the functioning of the mitral valve and the left ventricle. Cardiac magnetic resonance is a valuable imaging modality to evaluate papillary muscle morphology, tissue characterization and function. Moreover, LGE images, contrast enhancement sequences acquired 10-15 minutes after contrast administration, are useful to characterize tissue fibrosis caused by cardiomyopathy, myocarditis and infarction.

Commonly papillary muscle fibrosis is due to coronary artery disease followed by other causes like infective endocarditis, acute valvular regurgitation, cardiomyopathies and endocardial fibrosis. [1]

Mitral valve regurgitation may occur in patients primary dysfunction of the valve or with dilatation of mitral anulus. In this case mitral regurgitation was due to Barlow’s disease and this disease can be associated with fibrosis of papillary muscles.

Mitral annular disjunction (MAD) is an abnormal atrial displacement of the mitral valve leaflet hinge point, away from ventricular myocardium and it is associated with Barlow’s disease. Bileaflet MVP, papillary muscle fibrosis and MAD have been associated with an increased risk of malignant ventricular arrhythmias which may lead to sudden cardiac death.  Our case report demonstrates mitral annular disjunction associated with papillary muscles fibrosis, observed as hyperenhancement of papillary muscles tip, in patient with Barlow’s disease [2].

Considering the presence of papillary muscles LGE and MAD, patient underwent to holter dynamic ECG monitoring. 

Take-home message

• Coronary Computed Tomography Angiography is useful in rule out of coronary artery disease.
• Cardiac magnetic resonance is a valuable imaging modality to better characterize myocardial tissue.
• Multimodal imaging, involving echocardiography, CCTA and CMR can be useful complex conditions which involve different cardiac structures.