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 Batt, MD; Wilfred Mamuya, MD, PhD and Suhny Abbara MD

Clinical History
A 29-year-old woman who was born and raised in the Philippines, presented to MGH with worsening dyspnea, hemoptysis and decrease in exercise tolerance. Her past medical history was remarkable for rheumatic valvular heart disease, and a history of decompensated heart failure during her first pregnancy at the age of 26. She underwent  percutaneous mitral balloon valvuloplasty (BMVP) 8 years prior to this presentation, with a second uneventful pregnancy following her procedure.

A cardiac ultrasound (TTE) revealed moderately-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. 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 of pulmonary vasculature (proximal redistribution of pulmonary blood flow) and “double contour” sign (left atrial enlargement) (Figure 1). Cardiac CTA showed normal coronary arteries with no luminal stenosis (Figure 2), dilatation of the main pulmonary artery, and a mitral valve that had diminished area, a fish-mouth appearance (Figure 3), which measured 1.2 cm2 by planimetry, which correlated perfectly with the TTE derived valve area.


Figure 1


Figure 2


Figure 3


(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. 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 [1]. 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 [3]. Moreover, it is also able to provide superior quality imaging of valve anatomy. For this reason it should be considered as a primary imaging modality in patients with low-intermediate pre-test probability of coronary artery disease, who are scheduled to undergo cardiac surgery. Our 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. Palacios IF, et al. Which patients benefit from percutaneous mitral balloon valvuloplasty? Prevalvuloplasty and postvalvuloplasty variables that predict long-term outcome. Circulation. 2002;105(12):1465-71
3. Bouleti C, et al. Late results of percutaneous mitral commissurotomy up to 20 years: Development and validation of a risk score predicting late functional results from a series of 912 patients. Circulation 2012; 125:2119-2127
4. 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, MD
MGH Department of Radiology
Wilfred Mamuya, MD, PhD
MGH Department of Cardiology