Up to 50% of patients undergoing coronary angiography are found to have normal coronary arteries though experiencing angina-like symptoms like dyspnea or chest pain (Ong et al., J Am Coll Cardiol 2012). The origin of their symptoms is frequently found in an impaired vasomotion of the coronary vasculature, either presented by a reduced vasodilative capacity, an increased vasoconstrictive potential or a combination of both. For diagnosis of this disease, the vascular functionality might be tested during coronary angiography right after exclusion of obstructive events. During this so-called Interventional Diagnostic Procedure (IDP) as introduced in the CorMicA (Ford et al. JACC 2018), these two diverging mechanisms might be evaluated. For testing of the vasoconstrictive potential, a vasoconstrictive agent is injected into a selected coronary artery in order to assess if both the patients´ usual symptoms are reproducible and if ischemic ECG changes occur, both serving as an indicator of vascular spasms. Depending on the size of the coronary arteries affected, this severe vasoconstriction might either be visually visible during coronary angiography (indicating epicardial spasm) or remain invisible (indicating microvascular spasm). The vessels´ ability to dilate, on the other hand, is tested by observing the alteration in coronary blood flow and/or vascular resistance after induced dilation of the microvasculature. Depending on the results of IDP, different therapeutic recommendations may result, emphasizing the crucial role of proper early diagnosis. This collection shall describe the different techniques frequently performed during an IDP, varying from center to center.