[The platelet factor 4 content of the blood in induced myocardial ischemia in patients with stable stenocardia].

Seventeen patients were studied: 10 with stable angina and coronary atherosclerosis, and 7 with "intact" coronary arteries (a control group). All patients underwent coronarography and catheterization of the coronary sinus. Blood samples were obtained from the left ventricle and coronary sinus in 3 points: at rest, peak pacing, 10 min after pacing. All patients with stable angina had positive atrial pacing test (pain and/or ECG deviations and lactate production), in control group similar changes were not observed. However, no statistically significant difference was found in platelet factor (IV) 4 levels between the groups and following pacing; the level of platelet factor IV was near 90 ng/ml. It is concluded that patients with stable angina during pacing-induced ischemia had no significant platelet activation, which may provoke thrombotic events.