Background: According to curent guidelines, tilt testing is an established diagnostic tool in patients with recurrent syncope of unknown origin.

Objective: We describe a case of a 76 year-old woman who suffered from two syncopies of unknown origin, while sitting and standing. The 12-lead resting ECG as well as holter monitor and echocardiographic examination carried out in advance were unremarkable, so the patient was presented for outpatient tilt table examination.
Methods: Nitrate stimulated tilt test with a passive tilt phase of 20 minutes, followed by tilt angle of 70° with an observation time of 16 min after 0,4 mg s.l. nitrate administration was performed under continuous ECG and blood pressure monitoring. 
Results: Continuous lowering of blood pressure as an expression of a vasodepressor response, led to newly emerged persistent ST-segment elevations in inferior leads (II, III, aVF) with consecutive ST-segment depression in anterior leads (I, aVL, V2-V4). Immediate left heart catheterization revealed a severe 3 vessel obstructive coronary artery disease with collateralizations and acute total occlusion of the right coronary artery.
Conclusion: In rare cases, vasodepressor response during tilt testing can unmask coronary heart disease and in worst case trigger myocardial infarction.