Echocardiogram apical 4-chamber with and without saline contrast showing enlargement of the right heart chambers

Panel A: Apical four-chamber view from a patient with severe idiopathic pulmonary arterial hypertension associated with tricuspid regurgitation. There is a large apex-forming right ventricle (RV), large right atrium (RA), and small left ventricle (LV) and left atrium (LA).
Panel B: Agitated saline contrast is injected intravenously and results in RA and RV opacification; four bubbles are seen in the LV (arrow), possibly due to right-to-left flow across a patent foramen ovale.
Panel C: Similar echocardiographic findings can be seen in patients with primary volume overload of the right ventricle. This panel shows an apical four chamber view from a patient with a large left-to-right shunt due to an atrial septal defect (ASD). The RV is apex-forming but the RV and RA are not as large as in panel A.
Panel D: Contrast is injected intravenously and a few bubbles are seen in the LV; more importantly, there is a prominent negative contrast (nc) effect due to opacified atrial blood.