Which of the following can be obtained during a right heart catheterization?

• A. Left atrial pressure via pulmonary capillary wedge pressure or transeptal approach
• B. Brain perfusion pressure
• C. Coronary bypass graft flow
• D. Serum electrolyte levels

Answer: (A)

Right heart catheterization can estimate left atrial pressure by using the pulmonary capillary wedge pressure. When the catheter is advanced into a small branch of the pulmonary artery and the balloon is inflated to occlude the vessel, the pressure measured beyond the occlusion reflects the pressure in the left atrium, assuming normal pulmonary circulation. In some cases, a transeptal puncture can provide direct left atrial pressure measurement. This is the key measurement obtained with this procedure because it links the right-sided study to left-sided filling pressures. Other options aren’t determined by a standard right heart cath: brain perfusion pressure isn’t measured in this context, coronary bypass graft flow is assessed by other techniques, and serum electrolyte levels are obtained from lab blood tests rather than the catheter itself.