Transcranial doppler ultrasound is a diagnostic tool that involves a simple intravenous injection of saline under minimal sedation. It is primarily utilized to further diagnostically evaluate a patent foramen ovale defect.

• Transcranial doppler ultrasound bubble test can be used to determine hemodynamic interaction between atria of the heart.
• Non-invasive ultrasound method.
• Operated by a hand-held doppler transducer that functions on a pulsating low-frequency.
• Requires no sedation.
• Involves a simple intravenous injection of saline solution.
• Used as a testing standard in clinical trials of patent foramen ovale closure devices and in studies ivestigating the relationship and interconnectivity of patent foramen ovale, stroke and migraines.

• Effective in detecting narrowing of cerebral arteries.
• Effective in measuring hemodynamic circulation patterns within occluded diseased cerebral arteries.
• Effectively measures:

• Peak systolic velocity
• Peak diastolic velocity
• Mean velocity
• Pulsatility

• Usage of valsalva maneuver during testing can increase the visibility and overall detection of an atrial septal defect
• Less invasive than other methods
• Cost effective
• Can be completed in under an hour

• A defect may present in two ways:

• Small right-to-left shunt at start of systole (biphasic), associated with patent foramen ovale.
• Larger left-to-right shunt, associated primarily with atrial septal defect.

• Visualization of bubbles in the left atrium and left ventricle.

• Transcranial Doppler ultrasound Bubble study has minimal or no complications.^[1]
• One study which detected an incidence of adverse events of 0.3% or greater and found 0 events; indicating a high confidence interval (alpha value was 0.05).^[1]

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