An Accidental Hole in the Heart
A 55-year-old post-menopausal Caucasian woman with a medical history significant for controlled hypertension and a left breast cyst was referred to an oncologist for a 2-year history of an expanding left breast mass associated with bleeding and dermal changes. She was diagnosed with ER+, PR+, HER-2- left-sided locally advanced invasive ductal carcinoma. During initial investigations, staging computed tomography (CT) demonstrated an enlarged main pulmonary artery (PA) and right and left branches. A mosaic attenuation pattern throughout both lungs suggested pulmonary arterial hypertension (Figure 1). A cardiology referral and echocardiogram were requested for further assessment.
Figure 1: Chest CT With Contrast Showing Mosaic Attenuation of the Bilateral Lung Fields and Enlargement of the Main PA and Right PA
Clinically, she had no symptoms of angina or dyspnea and had a good exercise tolerance. She had no previous history of deep vein thromboses or pulmonary emboli. Physical examination showed a blood pressure of 137/87 with a regular heart rate of 91 bpm. Adventitious sounds were heard to both bases. The jugular venous pressure was not elevated. S1 and S2 were normal. There was a grade 1/6 systolic crescendo decrescendo systolic murmur over the second left intercostal space. An electrocardiogram showed sinus rhythm with right axis deviation (Figure 2). Her echocardiogram showed a dilated right ventricle (RV) (Video 1) with normal function. There was insufficient tricuspid regurgitation (TR) to estimate right ventricular systolic pressure (RVSP) (Figure 3), but the septum was abnormally "D-shaped" (Video 2). A saline bubble study was positive for an interatrial shunt (Video 3). Pulmonary function testing and a sleep study revealed only mild restrictive lung disease and mild sleep apnea, respectively.
Figure 2: Electrocardiogram Showing Sinus Tachycardia at 108 bpm With Right Axis Deviation
Which of these statements is TRUE?