[Relationship of paradoxical vasoconstriction induced by acetylcholine to risk factors for ischemic heart disease]

Acetylcholine test is widely used for the investigation of endothelium function. Acetylcholine induces paradoxical vasoconstriction, if endothelium of coronary artery is damaged. The aim of this study was to investigate the endothelium dysfunction among the patients who have complaints of the chest pain and at the same time no significant changes are found in their coronary arteries by angiography. The impact of the risk factors (smoking, hypertension, positive family history, and hypercholesterolemia) to the lack of endothelium function was studied as well. Intracoronary acetylcholine test was performed for 100 patients (52 males and 48 females). Acetylcholine was given in two steps (10(-6) mol/l and 3.3x10(-6) mol/l) followed by the 300 microg of nitroglycerin. The change of the diameter in comparison with baseline was assessed in left anterior descending and left circumflex arteries. Vasoconstriction of more than 5% from baseline was interpreted as endothelium dysfunction. Coronary vessels from 8 patients reacted to the acetylcholine infusion by vasodilatation and in 92 patients paradoxical vasoconstriction of more than 5% was induced. However, such risk factors as smoking, hypertension, positive family history, and acute coronary syndrome in the past had negative impact to the endothelium dysfunction (p<0.05). The more risk factors patient had, the more expressed his reaction to acetylcholine was (p<0.05). The smaller diameter of segment was, the more expressed contraction to acetylcholine it exhibited (p<0.05). Left coronary artery mainly was unresponsive to the acetylcholine.