D
Dirk
Folks,
one problem with mechanical heart valves maybe that they produce HITS "High Intensity Transient Signals" or MES "Microembolic Signals" when the arteries going to brain are measured with a doppler echo.
These signals are possibly due to gas bubbles generated at the mechanical valve due to cavitation.
ATS valves produce less HITS than SJM valves. Medtronic Hall valves produce nearly no HITS, also biological valves do not produce them.
There is no correlation between anticoagulation and HITS rate.
Some studies suggest that they have neurological effects, other studies do not find any relation of neurological symptoms.
The situation is unclear, but it does effect the decision making to take a mechanical or biological valve.
Have you any opinion about the situation?
Here are some links:
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9614290
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9731602
http://stroke.ahajournals.org/cgi/content/full/29/9/1821
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9731593
http://stroke.ahajournals.org/cgi/content/full/29/9/1821
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11385377
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12694774
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12614792
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10772054
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11145405
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10735407
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12493511
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12865613
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12380477
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11788250
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10393412
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9445343
Best greetings
Dirk
one problem with mechanical heart valves maybe that they produce HITS "High Intensity Transient Signals" or MES "Microembolic Signals" when the arteries going to brain are measured with a doppler echo.
These signals are possibly due to gas bubbles generated at the mechanical valve due to cavitation.
ATS valves produce less HITS than SJM valves. Medtronic Hall valves produce nearly no HITS, also biological valves do not produce them.
There is no correlation between anticoagulation and HITS rate.
Some studies suggest that they have neurological effects, other studies do not find any relation of neurological symptoms.
The situation is unclear, but it does effect the decision making to take a mechanical or biological valve.
Have you any opinion about the situation?
Here are some links:
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9614290
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9731602
http://stroke.ahajournals.org/cgi/content/full/29/9/1821
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9731593
http://stroke.ahajournals.org/cgi/content/full/29/9/1821
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11385377
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12694774
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12614792
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10772054
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11145405
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10735407
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12493511
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12865613
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12380477
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11788250
http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10393412
http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9445343
Best greetings
Dirk