The following information was obtained during the insertion of a right heart catheter
|
RA |
14 |
mm Hg |
|
RV |
105/14 |
mm Hg |
|
PA |
33/18 |
mm Hg |
|
PAOP |
14 |
mm Hg |
|
CI |
2.4 |
L/min/m2 |
- What dominant abnormality is indicated by the right heart catheter data?
- List two likely causes
College Answer
a)
Pressure gradient between RV and PA
Pulmonary valve stenosis
Supravalvular or RVOT stenosis
Discussion
This answer relies on the candidate to have some recollection of normal right heart pressures.
In order to make this analysis easier, I will present the data again, but this time with normal values included.
| RA | 14 mmHg | [ 2-6mmHg ] |
| RV | 105/14 mmHg | [ 15/2 - 30/8 mmHg ] |
| PA | 33/18 mmHg | [ 15/8 - 30/15 mmHg ] |
| PAOP | 14 mmHg | [ 6 - 12 mmHg ] |
| CI | 2.4 L/min/m2 | [ 2.5 - 4 L/min/m2 |
One immediately notices the massive difference between the pressure in the RV and the pressure in the pulmonary arteries. Surely, at least the systolic should be the same?
And then one's attention is drawn to the monstrously elevated RV pressure.
Thus, one forms the impression that the RV must generate vastly increased pressures in order to generate a relatively normal PA pressure. This is the case in RVOT obstruction or in pulmonic valve stenosis.
References
Normal Hemodynamic Parameters and Laboratory Values pocket card from Edwards Life Sciences, a manufacturer of Swan-Ganz catheters.