Thread by @NephroP

#POCUS #echofirst The correct answer is dilated coronary sinus [48% got it right (of 229 votes)]. From #IMPOCUS standpoint, 2 main causes: persistent left superior vena cava and pulmonary HTN. This pt had the former. Normal anatomy of the coronary sinus (Read #thread)👇 #MedEd

https://twitter.com/NephroP/status/1272314795484643328

More anatomy: 3D CT angio
We need to understand the anatomy first to understand #pocus orientation

Original image shows the typical location of CS in PLAX view. Don't confuse with descending aorta. You can also see CS from the apical window. From apical 4C, tilt the transducer posterior (in the opposite direction as you would for the 5-chamber view) #POCUS

Gross #anatomy of persistent left SVC (as it drains into CS, it gets enlarged). So, SVC drains into CS and CS into the right atrium (in most cases). #MedEd

What to do if you identify dilated CS & suspect persistent left SVC (typically an asymptomatic person) - refer to cardiology for bubble study: In this #echofirst example, note that the CS opacifies before the right side of the heart in a patient with persistent left SVC.

Other causes of CS dilation

Further reading: ncbi.nlm.nih.gov/pmc/articles/P…