Mass General Hospital
JANUARY 2013
ISSUE 52
 
 
Rheumatic Heart Disease
Lorenzo Azzalini, MD, MSc; Ali Karaosmanoglu, MD; Rajiv Gupta, MD, PhD; Thomas MacGillivray, MD; Ami Bhatt, MD, FACC; Wilfred Mamuya, MD, PhD and Suhny Abbara, MD

  
  Clinical History
A 30-year-old woman, who was born and raised in Asia, presented with worsening dyspnea, hemoptysis and decrease in exercise tolerance. Her past medical history was remarkable for rheumatic valvular heart disease and decompensated heart failure during her first pregnancy at the age of 21. She underwent percutaneous mitral balloon valvuloplasty (PMV) 8 years prior to the most recent presentation, with a second uneventful pregnancy following that procedure.

A transthoracic echocardiography (TTE) revealed moderate-to-severe mitral stenosis (MS) with a valve area of 1.2 cm2, severe aortic stenosis with moderate aortic regurgitation (valve area 0.7 cm2), and moderate pulmonary hypertension (50 mmHg). The patient was not a candidate for repeat balloon valvuloplasty, and surgery was recommended. A chest X-ray and a cardiac CTA were requested as part of the pre-surgical work-up.

Findings
A chest X-ray showed prominence and cephalization (redistribution) of pulmonary vasculature and a right cardiac "double contour" sign (left atrial enlargement) (Figure 1). Cardiac CTA in diastole showed normal coronary arteries with no luminal stenosis (Figure 2), dilatation of the main pulmonary artery, and a thickened mitral valve that showed spotty calcification (Figure 3), and had a fish-mouth appearance (Figure 4) and an opening area of 1.2 cm2 by planimetry, which correlated with the TTE-derived valve area. The aortic valve was also thickened (Figure 3).


Figure 1
Figure 2

Figure 3
Figure 4

(Click on image to enlarge)

Figure 1: Chest X-ray showing signs of left atrial (LA) enlargement: “double contour” sign (small black arrows), slight bulge in LA border due to enlargement of LA appendage (asterisk) and splaying of the carina to >90° degrees (the carina lies above LA; obtuse angle). Moreover, cephalization and prominence of pulmonary vasculature (sign of pulmonary hypertension) can be observed (white arrows).

Figure 2: Cardiac CT 3D volume rendering and multiplanar reconstructions of the coronary arteries, showing no luminal stenosis in the right and left coronary system.

Figure 3: Cardiac CT. Three-chamber long-axis view that shows the aortic and mitral valves. The aortic valve is thickened (white arrow). The posterior leaflet of the mitral valve, which is also thickened, shows spotty calcification (black arrow).

Figure 4: Cardiac CT. Two-chamber short-axis view of the mitral valve, which is narrowed and appears to have the shape of a fish mouth (arrow).

Discussion
Due to evolving immigration trends, MS is once again been encountered with increasing frequency in the developed world. Persistent inflammatory valve damage and hemodynamic injury are the main contributors to gradual progression of the disease. The main anatomic abnormalities are leaflet thickening, nodularity, calcification and commissural fusion, all of which eventually result in narrowing of the valve orifice. Most patients are symptomatic when the mitral valve area approaches 1.5 cm2 (normally 4-6 cm2), and when the aortic valve area is below 1 cm2.

Cardiac CT angiography has been shown to safely exclude obstructive coronary atherosclerosis prior to cardiac surgery. Moreover, it is also able to provide imaging of valve anatomy. For these reasons it should be considered in patients with low-intermediate pre-test probability of coronary artery disease, who are scheduled to undergo cardiac surgery. This patient underwent surgery for replacement of her mitral and aortic valves, and her post-operative course was uneventful.


  
 
REFERENCES
1. Chandrashekhar Y, et al. Mitral stenosis. Lancet. 2009;374(9697): 1271-83
2. Goetti R, et al. Evaluation of cardiac morphology, function, and perfusion at low radiation dose before mitral valve surgery. J Cardiovasc Comput Tomogr. 2011; 5(4):271-2
   
 

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Editors:
Suhny Abbara, M.D.
MGH Department of Radiology
Wilfred Mamuya, M.D., Ph.D.
MGH Division of Cardiology

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