[Effect of stress electrocardiogram on platelet function, concentration of von Willebrand factor and fibrinogen in hypertensive patients and healthy subjects].
The aim of the present study was to investigate the effect of the treadmill electrocardiogram (TMECG) on thrombotic risk factors in hypertensive patients and normal individuals. Twenty patients, 10 males and 10 females between 40 and 55 years of age, were studied and twenty normal persons of matching sex and age were chosen as controls. Blood samples were obtained before and immediately after the TMECG. Platelet counts and function as well as fibrinogen and von Willebrand factor (vWF) levels were determined in each sample. A significant increase in platelet number and aggregation with collagen and ristocetin was observed in all groups after the TMECG. Fibrinogen and von Willebrand factor levels were also significantly increased in all individuals. It is known that platelets play an important role in the formation of thrombi and the enhancement in their number and activity, in certain circumstances, might favor the development of a thrombotic episode. Elevated fibrinogen concentrations are considered an independent cardiovascular risk factor. The above changes in patients with other predisponent factors for cardiovascular events, such as arterial hypertension, enhances the possibility of a vasooclusive episode. It is recommended therefore, that before suggesting a physical activity to a hypertensive patient, other parameters, such as age, previous training and the existence of other cardiovascular risk factors should be considered.
Torres-Guerra
E
E
Instituto de Investigaciones Clínicas, Apartado 1151, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela.
Diez-Ewald
M
M
Vizcaíno
G
G
Arteaga-Vizcaíno
M
M
Sulbarán
T
T
D000328:Adult; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005340:Fibrinogen / Q000032:analysis*; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation; D012307:Risk Factors; D014841:von Willebrand Factor / Q000032:analysis*
D014841:von Willebrand Factor; D005340:Fibrinogen