Mitral Valve Aneurysm

A 46-year-old woman, who was intermittently treated with antibiotics prescribed by four different physicians during two months, was hospitalized because of recurrent fever. Physical examination revealed a pulse rate of 92 beats/min, blood pressure of 140/67 mmHg, and a grade 4/6 diastolic murmur heard loudest at the third left sternal border. The first 2 sets of blood cultures were positive for Streptococcus mutans. However, her laboratory examination, which could be affected by “incomplete” antibiotic treatments, revealed mild inflammation with an elevated C-reactive protein level of 3.3 mg/dL and a white blood cell count of 9130/mm³. A transthoracic echocardiogram showed moderate aortic regurgitation due to the bicuspid aortic valve, and a mildly enlarged left ventricular diastolic dimension (57 mm). In addition, a mass was seen on the medial side of the anterior mitral leaflet (A3), against which the aortic regurgitant blood flow was directed ([Fig. 1a]). An “ellipsoid body-like” mass was clearly observed on a three-dimensional echocardiogram ([Fig. 1b]). Transesophageal echocardiograms showed small vegetations attached to the noncoronary cusp of the aortic valve ([Fig. 2a, b]), and the mass at the mitral valve ([Fig. 2c]). A repeat transesophageal echocardiogram after intravenous administration of penicillin G for 1 month showed no changes in the size and shape of the mass, but an echolucent area in the mass was apparent ([Fig. 2 d]). Antibiotic therapy was continued with oral penicillin for 1 more month. Transthoracic and three-dimensional echocardiographic examinations were repeated, and the mass was found to have transformed into a saccular structure compatible with mitral valve aneurysm ([Fig. 1c, d]). Therefore, we concluded that the mass was an abscess formed by aortic valve endocarditis, and its liquid content was drained during the antibiotic therapy. A 64-row multi-detector computed tomography image with intravenous contrast also detected a saccular structure at the mitral valve ([Fig. 3a]). Surgical findings confirmed aortic valve endocarditis, and the infected valve was replaced with a mechanical valve. Observation of the anterior mitral leaflet revealed an aneurysm with an orifice to the left ventricle, but no perforation ([Fig. 3b]). The mitral valve was repaired using autologous pericardium, and the postoperative course of the patient was satisfactory, but it resulted in an uneventful outcome.

Fig. 1 a A transthoracic echocardiogram in the parasternal long axis view obtained at admission shows a mass at the anterior mitral leaflet (arrow head). A regurgitant blood flow is striking the medial side of the mitral valve and the mass. LV, left ventricle; LA, left atrium. b A three-dimensional echocardiogram in the parasternal long axis view obtained at admission shows an “ellipsoid body-like” mass at the anterior mitral leaflet (arrow head). LV, left ventricle; LA, left atrium. c A repeat transthoracic echocardiogram in the parasternal long axis taken after 2 months shows a saccular structure at the anterior mitral leaflet where the mass was located (arrow). d A repeat three-dimensional echocardiogram in the parasternal long axis, taken after 2 months, show a saccular structure at the anterior mitral leaflet where the mass was located (arrow).

Abb. 1 a Ein transthorakales Echokardiogramm im parasternalen Längsachsenblick (mit Erlaubnis zur Verfügung gestellt) zeigt eine Raumforderung am vorderen Mitralsegel (Pfeilspitze). Ein Regurgitationsblutfluss trifft die mediale Seite der Mitralklappe und der Raumforderung. LV, linker Ventrikel; LA, linkes Atrium. b Ein dreidimensionales Echokardiogramm im parasternalen Längsachsenblick (mit Erlaubnis zur Verfügung gestellt) zeigt eine „ellipsoide körperähnliche“ Raumforderung am vorderen Mitralsegel (Pfeilspitze). LV, linker Ventrikel; LA, linkes Atrium. c Ein wiederholtes transthorakales Echokardiogramm in der parasternalen Längsachse, das nach 2 Monaten aufgenommen wurde, zeigt eine sackförmige Struktur am vorderen Mitralsegel, an der Stelle, wo die Raumforderung lokalisiert wurde (Pfeil). d Ein wiederholtes dreidimensionales Echokardiogramm im parasternalen Längsachsenblick nach 2 Monaten zeigt eine sackförmige Struktur am vorderen Mitralsegel, an der Stelle, wo die Raumforderung lokalisiert wurde (Pfeil).

Fig. 2 a A transesophageal echocardiogram obtained at admission shows a bicuspid aortic valve. LV, left ventricle; RA, right atrium. b A transesophageal echocardiogram obtained at admission shows small vegetations attached to the noncoronary cusp of the aortic valve (arrow). c A transesophageal echocardiogram obtained at admission shows a mass on the medial side of the mitral valve (A3). LV, left ventricle; LA, left atrium. d A repeat transesophageal echocardiogram obtained after 1 month shows the mass with an echolucent area

Abb. 2 a Ein transösophagiales Echokardiogramm (mit Erlaubnis zur Verfügung gestellt) zeigt eine zweisegelige Aortenklappe. LV, linker Ventrikel; RA, rechtes Atrium. b Ein transösophagiales Echokardiogramm (mit Erlaubnis zur Verfügung gestellt) zeigt kleine Wucherungen am nicht koronaren Segel der Aortenklappe (Pfeil). c Ein transösophagiales Echokardiogramm (mit Erlaubnis zur Verfügung gestellt) zeigt eine Raumforderung an der medialen Seite der Mitralklappe (A3). LV, linker Ventrikel; LA, linkes Atrium. d Ein wiederholtes transösophagiales Echokardiogramm, das nach einem Monat aufgenommen wurde, zeigt die Raumforderung mit einem echotransparenten Bereich.

Fig. 3 a A 64-row multidetector computed tomography image, with intravenous contrast obtained after 2 months shows a mitral leaflet aneurysm (arrow). LV, left ventricle; LA, left atrium; RA, right atrium; Ao, aorta. b A macroscopic photograph of the left atrium during surgery (surgeon’s view) shows the anatomy of the mitral valve after the resection of the body of the aneurysm. The round orifice of the aneurysm on the medial side of the anterior mitral leaflet is exposed.

Abb. 3 a Eine 64-raw Multi-Detektor-Computertomografie, die nach 2 Monaten mit intravenösem Kontrastmittel durchgeführt wurde, zeigt das Mitralklappenaneurysma (Pfeil). LV, linker Ventrikel; LA, linkes Atrium; RA, rechtes Atrium; Ao, Aorta. b Eine makroskopische Fotografie des linken Atriums während einer Operation (Blick des Chirurgen) zeigt die Anatomie der Mitralklappe nach der Entfernung des Aneurysmakörpers. Die runde Öffnung des Aneurysmas an der medialen Seite des vorderen Mitralsegels ist freigelegt.