Platelet adhesion is related to heart rhythm disturbances in the acute phase of myocardial infarction.

This study examines the relationship between platelet adhesion, aggregation and the occurrence of heart rhythm disturbances in 43 consecutive patients (mean age 58) admitted to a coronary care unit with acute myocardial infarction. Blood for platelet studies was taken prior to institution of any medication and heart rhythm was monitored (Holter) for 24 h after admission. The control group consisted of 22 healthy subjects (mean age 55 yr). Platelet adhesion to collagen was measured in EDTA-platelet rich plasma by recording the changes in light transmission in an optical aggregometer. Platelet aggregation was measured by the Born method. Platelet adhesion was increased in the group of patients with acute myocardial infarction as compared to controls and was significantly higher in the patients with complex ventricular arrhythmias (Lown 3-4b, n = 18) than in the patients with stable rhythm. Platelet aggregation in the patients with acute myocardial infarction did not differ significantly from the controls and was not related to heart rhythm disturbances. The causal relationship of increased platelet adhesiveness to collagen and heart rhythm disturbances in acute myocardial infarction remains to be established.