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

Figure 1

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

Figure 2

Video 1

Transthoracic echocardiogram (TTE) in apical four-chamber view showing a dilated RV compared with the left ventricle (LV). The basal RV:LV end-diastolic diameter ratio was abnormal: >2/3.

Figure 3

Figure 3
Continuous wave Doppler through the tricuspid valve in parasternal long axis. Insufficient TR waveform to calculate RVSP.

Video 2

TTE in parasternal short axis at the level of the papillary muscles showing a flatted D-shaped septum, denoting RV volume overload and some RV pressure overload.

Video 3

TTE showing a positive saline bubble study with Valsalva, i.e., bubbles crossing the interatrial septum.

Which of these statements is TRUE?

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