Functional magnetic stimulation: a new modality for enhancing systemic fibrinolysis.
OBJECTIVE
To investigate whether functional magnetic stimulation (FMS) of the leg muscles could enhance systemic fibrinolysis.


METHODS
A within-subject analysis of systemic fibrinolysis before and after 60 minutes of FMS.


METHODS
The Functional Magnetic Stimulation and Special Coagulation Laboratories in the Spinal Cord Injury Service at a Veterans Administration health care facility.


METHODS
Twenty healthy volunteers were recruited. The exclusion criteria were: (1) personal or family history of venous or arterial thrombosis, (2) personal or family history of cardiac arrythmias, (3) current use of medication, and (4) the presence of a cardiac pacemaker or other metallic implants.


METHODS
Whole blood clot lysis time (WBCLT) and tissue plasminogen activator (t-PA) antigen determined at baseline and 10 and 60 minutes after FMS.


RESULTS
A significant decrease was observed in the mean WBCLT after FMS. The WBCLT decreased from 17+/-1.3 h before FMS to 12+/-1.0 h and 11+/-0.8 h at 10 and 60 minutes post-FMS, respectively. The mean t-PA antigen levels did not show a significant change (p = .6701) from pre-FMS (6.7+/-0.91 ng/mL) to 10 min post-FMS (6.8+/-0.91 ng/mL) and 60 min post-FMS (7.0+/-1.02 ng/mL). Several patterns of fibrinolytic response to FMS were observed. They differed in relation to the degree of enhancement, the period at which maximum enhancement occurred, and the corresponding t-PA antigen levels observed.


CONCLUSIONS
The FMS-induced contractions of the leg muscles enhanced systemic fibrinolysis ex vivo. The improvement in fibrinolysis occurred immediately after FMS and was also observed at 60 minutes post-FMS. FMS appears to produce a sustained enhancement of systemic fibrinolysis that may prove useful in deep-vein thrombosis prophylaxis.
D000328:Adult; D000368:Aged; D005342:Fibrinolysis; D006801:Humans; D007866:Leg; D008280:Magnetics / Q000627:therapeutic use*; D008875:Middle Aged; D018482:Muscle, Skeletal; D010959:Tissue Plasminogen Activator / Q000097:blood