Archived case 205 · June 23-June 30, 2016
Mitral stenosis
66-year-old female, preoperative radiographs, no history provided.
The question posed to readers
What is your diagnosis?
Images
Imaging findings
Radiographs demonstrate cardiomegaly, in particular enlargement of the left atrial appendage and left atrium consistent with underlying mitral valve stenosis. There is also prominence the central pulmonary vasculature consistent with pulmonary hypertension. The vascular clarity is maintained. Lateral views again show left atrial enlargement. Follow up postoperative radiographs demonstrate bilateral pleural drainage catheters. Changes of interval median sternotomy and clipping of the left atrial appendage. There are new moderate right and small left pleural effusions with associated basilar atelectasis. The cardiomediastinal silhouette is partially obscured, but appears grossly stable in size. There is mild pulmonary edema. Answer Diagnosis: Mitral stenosis
Diagnosis
Mitral stenosis
DISCUSSION
This patient presented with symptoms of chronic heart failure (NYHA III) and atrial fibrillation, was diagnosed with severe mitral stenosis (+ mild regurgitation) and pulmonary hypertension. The patient underwent m itral valve replacement, Maze procedure and left atrial appendage clipping.
Mitral stenosis is usually acquired most commonly caused by rheumatic heart disease . E xtensive mitral annular calcification in older patients can result in mitral stenosis. Rarely, mitral stenosis is congenital ( 0.5% of cases) .
Normal mitral valve orifice measures 4-6 cm2. When reduced to <2 cm2, left atrial pressure increases, subsequently pulmonary hypertension develops.
Chest radiographs may show:
· cardiomegaly, usually mild, may be absent
· straitening or convexity of the left heart border secondary to atrial appendage enlargement
· double right heart border (enlarged left atrium and normal right atrium)
A line from the mid-point of the right border of the double density to the midpoint of the border of the left mainstem bronchus should measure less than 7.5 cm in males and 7.0 cm in females.
· splaying of the subcarinal angle (>120 degrees), elevation of the left main bronchus
· left atrial enlargement on lateral view
A normal left atrium should also lie anterior to a line drawn down the center of the trachea on the lateral, non-rotated view.
· mitral annulus calcifications
· pulmonary edema
· findings related to pulmonary hypertension
Patients with mitral stenosis may present with hemoptysis and diffuse alveolar hemorrhage. Pulmonary hemosiderosis and ossifications may develop in long-standing mitral stenosis.
The Maze procedure is a surgical treatment for atrial fibrillation. It uses small incisions, radio waves, freezing, or microwave or ultrasound energy to create scar tissue. Left atrial clip is used for stroke prevention in patients with atrial fibrillation.
Selected Readings:
1. Parker MS , Rosado-de-Christenson M, Abbott GF. "Case 138 Mitral Stenosis" Chest Imaging Case Atlas. Thieme Medical Incorporated, 2012. 678-681. Print.
2. Morris MF, Maleszewski JJ, Rakesh M. Suri RM at al. CT and MR Imaging of the Mitral Valve: Radiologic-Pathologic Correlation RadioGraphics 2010 30:6, 1603-1620
3. Woolley K, Stark P. Pulmonary Parenchymal Manifestations of Mitral Valve Disease. RadioGraphics 1999 19:4, 965-972
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Original case written by its authors at Virginia Commonwealth University and published at this address as part of a weekly teaching collection. Reproduced here as an archive.