Valve gradients post surgery

[Mb]

Hello everyone:

I am just curious if anyone knows what the gradients should be for St. Jude mechanical aortic and mitral valves.

My husbands have increased, and I am wondering what that might mean.

Marybeth

 

[Dustin]

Maybeth,

What is your husbands body surface area (BSA) and the size of his St. Jude?

 

[tobagotwo]

Here are the manufacturer's post-surgical study averages for the St. Jude Regent, based on size of the valve. 25mm is the most common size for men: 19mm=9.0; 21mm=8.2; 23mm=5.7, 25mm=6.1. All gradients are measured in millimeters of mercury.

Don't be discouraged if his gradient is somewhat higher than that average. Luck of the genetic draw in valve size or some extra weight can make a difference. These are just averages.

Carbomedics 25mm is 8.3mmHg. The On-X 25mm is 4.2mmHg.

Tissue valves have a wider range: Medtronics Freestyle 25mm comes in at 4.9mmHg; Toronto SPV 25mm is 6.1mmHg; Edwards CEP 25mm is 12.5mmHg; the Medtronics Mosaic 25mm is 13.2mmHg.

Best wishes,

 

[Mb]

Hey guys:

Thank you for the info. I do not have his echo's here, so will have to wait till I have them in hand again. I know his gradients increased since the last echo, as the report indicates that. What does it mean, I guess is the question.

Mb

 

[Dustin]

Hey guys:

Thank you for the info. I do not have his echo's here, so will have to wait till I have them in hand again. I know his gradients increased since the last echo, as the report indicates that. What does it mean, I guess is the question.

Mb

If his gradients have increased it might mean - though it certainly need not - that his valve is too small for his Body Surface Area (BSA) and a larger valve would have been preferred. If this is the case we talk about mild-severe Patient-Prosthesis Mismatch (PPM). In order to diagnose the possible occurance of PPM you could ask your cardiologist about your husbands Indexed Effective Orifice Area (IEOA). In case IEOA <= 0.85 cm²/m² one could conclude "mild" PPM and when IEOA <= 0.65 cm²/m² one could say "severe" PPM. Another definition of PPM is solely based on gradients: If the mean gradient exceeds 21 mmHg one could suspect PPM.

It is possible to get an expected IEOA by the formula IEOA = EOA/BSA, where EOA is the in-vivo reference Effective Orifice Area, which can be obtained from the valve manufacturer.

 

[Mb]

Dear Bob and Dustin:

I will get to my office today, and post the gradients from the last echo. I do know, however, that the gradients were different for each valve he has. (Two St. Jude valves, aortic and mitral). He also needs to have his tricuspid valve repaired through annuloplasty, but he has postponed having that done to January. (Originally scheduled to be done in August) - Both posts only mention one gradient. Do I assume you are only mentioning the aortic gradient?

Marybeth

 

[Dustin]

Dear Bob and Dustin:

I will get to my office today, and post the gradients from the last echo. I do know, however, that the gradients were different for each valve he has. (Two St. Jude valves, aortic and mitral). He also needs to have his tricuspid valve repaired through annuloplasty, but he has postponed having that done to January. (Originally scheduled to be done in August) - Both posts only mention one gradient. Do I assume you are only mentioning the aortic gradient?

Marybeth

Yes, the aortic mean and maximum transvalvular pressure gradients are of interest. PPM frequently occurs after AVR, not MVR. Roughly, when the mean gradient exceeds 21 mmHg and the maximum gradient exceeds 40 mmHg, PPM is suspected.

 

[Mb]

Dear Dustin:

I've arrived at my office, and here are the gradients:

Aortic: April '06 - Peak is 30mmHg Sept. 05 Peak is 41mmHg
Mean is 18mmHg Mean is 21mmHg

Mitral April -06 Peak is 10mmHg Sept. 05 Peak is 12mmHg
Mean is 3mmHg Mean 3mmHg



He also has marked RV dilatation. Severe tricuspid regurgitation.

I didn't realize that they had gone down from the last echo, not up. From the previous echo done, to 9/05, there was increases.

Marybeth

 

[tobagotwo]

By their nature, the aortic and mitral valves usually have different gradients.

If the surgery were five years ago, and this wasn't an issue then, your husband would have had to put on a substantial amount of weight to have a valve/patient mismatch condition at this point. The decreasing gradient would seem to argue that he is not in that situation, if it was not there from the start.

There is not that much difference between the two measurements. The difference can be measurement variations caused by positioning or even having a different tech doing the readings.

The right heart's hypertrophy wouldn't usually affect the gradients in the left heart. Does your husband have pulmonary hypertension or COPD? They are frequent contributors to right-heart woes. The tricuspid regurgitation could be both a result of one of those and a cause of the right heart overworking (which causes hypertrophy).

Best wishes,

 

[Mb]

Dear Bob:

No he has neither PH, or COPD. His cardio thinks the right heart has enlarged due to chronic a-fib. Or, the left side was so bad for so long, that it strained the right side. His right ventricular pressure was only 35 on his last echo, but id did say it was likely an underestimate, based on the velocity of the regurgitation.

Bear in mind that it was on the Sept. '05 echo that it states the gradients have increased. And no, he weighs within 5 lbs. of what he did 5 years ago.
Marybeth