Uncommon Variant of Ebstein Anomaly With Tricuspid Stenosis
A 27-year-old previously healthy woman with no prior history of exercise limitations, shortness of breath, cyanosis, or arrhythmia became short of breath 10 months after her second successful pregnancy. Her shortness of breath was at rest accompanied by progressive edema, ascites, and later anasarca. An ECG revealed normal sinus rhythm with right atrial enlargement (Figure 1A), and chest x-ray revealed normal lung parenchyma with mildly enlarged cardiac silhouette (Figure 1B). A transthoracic echocardiogram demonstrated reduced left ventricular size with an ejection fraction estimated at 50%, severe right atrial enlargement, and severe right ventricular enlargement with dysfunction and was suspicious for severe displacement of the tricuspid valve leaflets toward the right ventricular apex, suggestive of Ebstein anomaly (EA) (Figure 2). She responded to intravenous diuresis with improvement in her right-sided heart failure. In light of her dilated, poorly functioning right ventricle, she was started on Coumadin. Repeat transthoracic echocardiogram 2 months later demonstrated displacement of the tricuspid valve into the right ventricular outflow tract with associated tricuspid stenosis (Figure 3, online-only Data Supplement Movie IA). The spectral Doppler analysis demonstrated a mean gradient of 4 to 5 mm Hg. Cardiac magnetic resonance imaging performed to assess right ventricular function demonstrated tricuspid valve displacement into the right ventricular outflow tract below the pulmonary valve with extensive mural thrombus/mass in the right ventricular apex extending into the right ventricular outflow tract (Figure 4, online-only Data Supplement Movie IIA and IIB).
In light of the right-sided heart failure and the findings of EA with tricuspid stenosis, surgical repair was recommended. Intraoperative transesophageal echocardiography confirmed the displacement of the tricuspid valve into the right ventricular outflow tract with associated tricuspid stenosis as noted by color flow Doppler (online-only Data Supplement Movies IIIA and IIIB). The pulmonary and aortic valves were normal. Surgical repair consisted of resection of the stenotic anterior tricuspid leaflet in the right ventricular outflow and removal of a large amount of organized thrombus from the right ventricle (Figure 5A and 5B). A porcine bioprosthetic tricuspid valve was placed, and a right atrial reduction was performed. Furthermore, a bidirectional Glenn shunt was placed to offload the right ventricle. The patient did well postoperatively with resolution of symptoms.
EA is a rare congenital anomaly of the tricuspid valve frequently associated with tricuspid regurgitation, right ventricular dysplasia, and, less frequently, atrial septal defect/patent foramen ovale, Wolf-Parkinson-White syndrome, and pulmonary valve stenosis.1 Patients with EA can present at different ages, depending on its structural and functional severity and associated defects.2 This case represents a rare form of EA with tricuspid stenosis very well tolerated into adulthood until the patient’s second pregnancy, which we believe played a role in her subsequent cardiac decompensation. Pregnancy is a known hypercoagulable state that could have precipitated thrombus formation in the relatively akinetic segment of the atrialized portion of the right ventricle, leading to obstruction of the right ventricular outflow tract near the stenotic tricuspid valve and ultimately causing low cardiac output, severe dyspnea, and right-sided heart failure.
Transthoracic echocardiography is the initial diagnostic procedure of choice in the assessment of the structural and functional severity of EA and its associated defects. At times, however, a transesophageal echocardiogram is needed to assess for the presence of an atrial shunt. In addition, cardiac magnetic resonance imaging is often used to assess right ventricular size and function, given some of the limitations of echocardiography. The findings on echocardiography and magnetic resonance imaging have a significant impact on the surgical repair and outcome of patients with EA.3
We gratefully acknowledge Mark A. Zangs and Timothy B. Seelinger for their expert technical assistance.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/120/1/e1/DC1.