Ultrasound Case 111

This is an apical 3 chamber view. 

This is done by finding the best apical window and from the standard 4 chamber view we rotate the probe 90 degrees counterclockwise to get a view with just the left ventricle and left atrium in plane.

The left atrium and ventricle appear to be contracting normally with a reasonable ejection fraction. 

The mitral valve is moving normally with no obvious pathology. 

However…if you look closely there are tiny bright “bubbles” moving through the left ventricle – this is consistent with spontaneous gas within the left side of the heart.

In a normal patient the bubbles should fill the right heart then be filtered by the lungs with little or no bubbles reaching the left side of the heart.

This clip shows the right heart filling with bubbles as the agitated saline is injected.  Then after approximately 3 heart beats the left side fills with bubbles also.

How do those bubbles get to the left ventricle?

 In order for bubbles to make it from right to left – there must be a shunt present.  There are two main shunts that may occur.

1. A intracardiac shunt such as a patent foramen ovale (PFO) would result in very early filling of the left ventricle within 1 or 2 heart cycles.  The bubbles would be seen crossing the interatrial septum into the RA.  This is not the case here. 
2. A pulmonary shunt occurs when there is abnormal vascular shunting of blood through the lungs.  IN this case the bubbles never pass through the microcirculation of the lungs.  This is typically delayed to the 3rd to 5th cycle after injection and we can see the bubbles return to the left atrium via the pulmonary veins.

This patient has hepatopulmonary syndrome. 

This is a complex syndrome associated with portal hypertension and advanced liver disease.  

Hepatopulmonary syndrome is the result of chronic inflammation and accumulation of macrophages in the lung which secrete various substances which results in angiogenesis, nitric oxide synthase induction and pulmonary vasodilation.  The end result is the formation of a significant pulmonary vascular shunt.

• Nickson C. Hepatopulmonary Syndrome. LITFL
• Bansal K, Gore M, Mittal S. Hepatopulmonary Syndrome. StatPearls
• Hopkins WE, Waggoner AD, Barzilai B. Frequency and significance of intrapulmonary right-to-left shunting in end-stage hepatic disease. Am J Cardiol. 1992 Aug 15;70(4):516-9.