Pressure gradient over Aortic tissue valve

[Johan]

I am now a year and a couple of months post AVR with a bovine pericardium valve. All 3 of my post surgery echocardiograms indicated the peak pressure gradient over the new valve to be about 30 mmHg. This is a huge improvement over my old stenotic and diseased valve's peak gradient of over 80 mmHg and I am very grateful for the intervention.

I am just a little disappointed that the new valve is not closer to the 10 to 20 mmHg I believe healthy un-stenosed native aortic valves run at.

A search on the internet and my valve's manufacturers website did not reveal the typical pressure gradient to be expected from a stented bovine pericardium valve of 21 mm diameter. I know it is dependent on the heart's condition, but had hoped for an indication at least.

Can anybody shed some light on this issue?

 

[Mentu]

Hi, Johan! I saw your post and checked my own numbers from the echo cardiogram I had in June. My mean pressure gradient was 18 mmHg with a peak of 31 mmHg. My Cardiologist said that post op pressures can be a little higher with stented valves like ours. He also said that after surgery, the mean pressure gradient is the more informative number rather than the peak. Is your mean figure closer to mine?

Johan, there is another issue with respect to echo cardiogram measurements and that is their reputed tendency to overestimate the value of the pressure gradient sometimes by as much as 10 mmHg. On the whole, I wouldn't worry about it too much unless with time it appears to be increasing.

Johan, I did find one study which reported pressure gradients post op for aortic valve replacement patients. The tests are from echo cardiograms. Here are the basic figures for these patients with stentless valves but at least you get a feel for the range of pressures that others have experienced after surgery. (If these values are representative, Johan, then you and I seem to fit right in but on the low side, especially, since we have stented valves.)

Valve______Mean PG______Number
Size_______mmHg_______of Patients

19 mm......29.8 ± 14.4.................9
21 mm......22.0 ± 8.9...............127
23 mm......19.6 ± 7.6...............176
25 mm......17.0 ± 6.9...............100
27 mm......14.8 ± 5.7................50


Valve______Max PG_______Number
Size_______mmHg_______of Patients

19 mm......54.2 ± 23.2..................9
21 mm......40.4 ± 14.5...............119
23 mm......35.5 ± 12.8...............149
25 mm......31.0 ± 14.9.................80
27 mm......26.7 ± 9.4...................47

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2146998/pdf/1749-8090-2-40.pdf

Take care, Johan.

Larry

 

[Johan]

Thank you Larry for your reassuring post. My reports all just show peak gradients. I will contact the cardiologist about the mean values.

Thanks for that study report, yes we seem to be right there but on the lower side, as you say, which to my mind is a good thing. I shall keep an eye on future values but not be concerned about it anymore. Johan