PMC8416758_01
(A,B) Transthoracic echocardiography in apical three-chamber view reveals an irregular mass (18 x 17 mm, arrow) attached to the atrial side of the anterior mitral leaflet. Color Doppler image reveals massive mitral regurgitation traversing the mass (arowheads). (C,D) Brain diffusion-weighted magnetic resonance imaging reveals multiple acute hyperintense ischemic strokes in both hemispheres (arrowheads). Ao, aorta; LA, left atrium; LV, left ventricle.
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revealed an irregular mobile mass with a wide base attached to the atrial side of the anterior mitral leaflet (AML) (Figure 1A). Doppler imaging revealed severe mitral regurgitation (MR) with high-velocity turbulent jet across the mass, leading to a suspicion of vegetations (Figure 1B; Supplementary Video 1). Differential diagnoses included chordal rupture, cardiac tumors including myxoma, cysts of the mitral valve (MV), and vegetations. Brain magnetic resonance imaging revealed acute multiple cerebral infarctions, suggesting systemic embolism (Figures 1C,D). Finally, the GBS infection was confirmed through pathologic examination and polymerase chain reaction (Figures 3E,F; Supplementary Figure 1).
(A) Three-dimensional TEE of the mitral valve. Note the two distinct ruptured perforations through the MVA (arrowhead and arrow, respectively). (B-E) Two or three-dimensional color Doppler TEE reveals that severe MR with two different jets communicate with the LA through the MVA: a superior jet (arrowhead) and a posterior jet (arrow), respectively. Note the MR with posterior jet heading toward the LA via the PML surface (dotted arrows). AML, anterior mitral leaflet; Ao, aorta; LA, left atrium; LV, left ventricle; MR, mitral regurgitation; PML, posterior mitral leaflet; MVA, mitral valve aneurysm, TEE, transesophageal echocardiography.
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Subsequent transesophageal echocardiography (TEE) revealed a saccular bulge of the thickened AML in A1, characterized by protrusion toward the LA with systolic expansion, and diastolic collapse into the left ventricle, consistent with MVA (Figure 2A; Supplementary Video 2).
(A) Intraoperative photograph of the mitral valve. Giant MVA (arrow, 28 x 23 x 12 mm) with ruptured perforation (arrowheads) is observed on the AML in A1. (B-D) Representative photographs of the extracted mitral valve leaflets [(B,C), AML; (D), PML]. Note the two distinct perforations through the MVA (arrow, arrowheads, respectively). (E,F) Histological findings of the resected MVA shows extensive valvular destruction with a high degree of neutrophilic inflammatory cell infiltration and bacterial agglomeration. [(E), Elastica van Gieson staining, Bar 200 mum; (F), Gram staining, 20 mum]. AML, anterior mitral leaflet; MVA, mitral valve aneurysm; PML, posterior mitral leaflet.
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Surgical findings included a large mass of vegetations on the A1 scallop of the MV with extensive valve destruction, which formed an aneurysm through which two ruptured perforations had occurred (Figures 3A-C). We confirmed the spread of infection onto the atrialis of the PML without evidence of perivalvular abscess (Figure 3D). Finally, the GBS infection was confirmed through pathologic examination and polymerase chain reaction (Figures 3E,F; Supplementary Figure 1).
Illustrated timeline of the case. AML, anterior mitral leaflet; Ao, aorta; DWI, diffusion-weighted image; GBS, Streptococcus agalactiae; HF, heart failure; IE, infective endocarditis; LA, left atrium; LV, left ventricle; MRI, magnetic resonance imaging; MEPM, meropenem; MR, mitral regurgitation; MVA, mitral valve aneurysm; MVR, mitral valve replacement; PCG, penicillin G; PML, posterior mitral leaflet; ST, sequence type; TEE, transesophageal echocardiography; TTE, transthoracic echocardiography; VCM, vancomycin.
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