Clip 1: The "rule of 1/3rds" is a tool that can help evaluate the heart. It states that on the parasternal long axis view the RV (top of the screen), aortic root, and left atrium should have roughly a 1:1:1 ratio in diameter. Here the RV breaks the "rule of 1/3rds" by being too big.
Clip 2: The apical 4 chamber view shows a RV (top L of the screen) that is larger than the LV (top R of the screen). Yes, ideally the septum should be situated straight up and down, but sometimes perfect is the enemy of the good.
A middle-aged F presents with chest pain and unilateral leg swelling. She's just off a transatlantic flight. She's tachycardic, but normotensive.
POCUS CARDIAC: parasternal long axis window (CLIP 1) is not the best to evaluate the right ventricle (RV), but it can raise your suspicion by breaking "The Rule of 1/3rds". The apical 4 chamber view (CLIP 2) shows a RV that is larger than the left ventricle (LV).
Clayton and Andrew nicely evaluated for RV dilation to help them risk stratify this patient with a high pretest probability of PE. She was treated prior to both CTPE and comprehensive TTE. The patient did well with heparin, TPA at the bedside in the MICU just in case. Well done!
Pearls: On the Apical 4 chamber view, try to situate the septum straight up and down to best describe the size of the ventricles. Ratio of RV size is normally <0.6 the size of the LV.