Cover Image: A rare and curable cause of left ventricular outflow obstruction
Jean-Christophe Eicher1, Etienne Tatou2, Hamid Makki1, Eve Justrabo3, and Jean-Eric Wolf1
1Department of Cardiology, University Hospital, Dijon, France
2Department of Cardiovascular Surgery, University Hospital, Dijon, France
3Department of Pathology, University Hospital, Dijon, France
A 60-year-old woman was referred for congestive heart failure. She had symptoms of exertional dyspnoea for 3 years and was put under beta-blocker treatment because of a former echocardiographic diagnosis of hypertrophic obstructive cardiomyopathy (HOCM). Recently, she had noted rapidly increasing shortness of breath and orthopnoea. On physical examination, a grade 3/6 ejection systolic murmur along the left sternal border and bilateral pulmonary crepitations were heard. Transthoracic echocardiography showed left ventricular outflow tract obstruction (LVOTO) due to a bubble-like structure, measuring 17 mm in diameter, and attached to the anterior mitral leaflet (Panels A and B). Peak gradient in the outflow tract was 60 mmHg. Transoesophageal echocardiography revealed intense echo contrast swirling inside the structure (Panel C). The patient was referred to the surgery department with a probable diagnosis of accessory mitral tissue, or a less likely hypothesis of necrosed tumour.
At surgery, the anomalous structure was seen through the opened aortic valve as a bluish mass attached to the chordae of the anterior mitral leaflet (Panel D). Once resected, it appeared as a roughly rounded, blood-filled cystic structure. Histologic examination showed that the wall was composed of collagenous tissue (Panel E), elastic fibres, and smooth muscle cells, and was lined by endothelial cells. The post-operative course was uneventful. The final diagnosis was blood cyst.
Blood cysts of the cardiac valves are very rare findings in adults. The origin of such cysts is controversial, the histological findings in the present case support the hypothesis of an ectatic vascular structure. The identification of this unusual cause of LVOTO is important as it is not expected to respond to pharmacological treatment or pacing as used in HOCM.
Figure legend
Panel A: Apical four-chamber echocardiographic view (LA, left atrium; LV, left ventricle).
Panel B: Colour Doppler aliased flow in the outflow tract (solid arrow) and mitral regurgitation (arrow).
Panel C: Transoesophageal echocardiographic view (LA, left atrium; LV, left ventricle; Ao, aorta).
Panel D: Operative view.
Panel E: Histological examination (Masson trichrome).
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