The present study is a randomized controlled double-blind single center study in order to investigate the effects of verbal suggestions ('vasodilatation') in combination with either a placebo-intervention (sodium chloride 0.9%) or an underdosed vasodilating medication (nitroglycerine) on the diameter of coronary arteries. 60 patients with a clinical indication to undergo a coronary angiogram were recruited in the German Heart Centre Munich. Patients with acute myocardial events and the necessity for coronary intervention were excluded from the study. Patients were randomized into one of four arms of the two experiments: