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Contrast Echocardiography - Bubble Study — EECC MCQ

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EasyCardiac ImagingContrast Echocardiography - Bubble StudyEECC

A 70-year-old woman with breathlessness and poor echocardiographic windows undergoes contrast echocardiography with agitated saline. After intravenous injection, microbubbles appear in the left atrium after 3 cardiac cycles. What does this finding indicate?

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Correct answer: D — Right-to-left intracardiac shunt, most likely a patent foramen ovale or atrial septal defect

Agitated saline contrast echocardiography (bubble study) is used to detect right-to-left shunts. Normally, agitated saline microbubbles are filtered by the pulmonary capillary bed and do not appear in the left heart. Appearance of microbubbles in the left atrium within 3-5 cardiac cycles indicates an intracardiac shunt (PFO or ASD), as transpulmonary passage takes longer (typically >5-6 cycles, suggesting an intrapulmonary shunt such as an arteriovenous malformation). The test sensitivity increases with Valsalva manoeuvre (which transiently increases right atrial pressure, opening a PFO). This is a key screening test in cryptogenic stroke workup and before interventional procedures.

Reference: BSE Guidelines on Contrast Echocardiography; ESC Position Paper on PFO