90 Chapter 5 Currently, diagnosis of CMD in routine ICFT protocol focuses mainly on reduced CFR both in presence or absence of abnormal MR as the cause of a reduced oxygen supply provoking ischemic complaints. CFR reflects myocardial blood flow (MBF). However, an unexplored feature of microvascular integrity is the myocardial blood volume (MBV) [%]. The coronary microcirculation determines 90% of the variation in MBF and contains most of the MBV. MBV is the fraction of tissue consisting of blood, and about 50% of the myocardial microcirculation simultaneously contains blood in resting conditions.19, 20 Table 1. Entities of INOCA according to the COVADIS-criteria Ischemia with no obstructive coronary arteries (INOCA) CMD16 1. Symptoms of myocardial ischemia: a. Effort and/or rest angina b. Angina equivalents (i.e. shortness of breath) 2. Absence of obstructive CAD (<50% diameter reduction or FFR >0.80) by a. Coronary computed tomographic angiography b. Invasive coronary angiography 3. Objective evidence of myocardial ischemia: a. Ischemic ECG changes during an episode of chest pain b. Stress-induced chest pain and/or ischemic ECG changes in the presence or absence of transient/reversible abnormal myocardial perfusion and/or wall motion abnormality 4. Evidence of impaired coronary microvascular function: a. Impaired coronary flow reserve b. Coronary microvascular spasm, defined as reproduction of symptoms, ischemic ECG shifts but no epicardial spasm during acetylcholine testing. c. Abnormal coronary microvascular resistance indices d. Coronary slow flow phenomenon Vasospastic angina17 1. Nitrate-response angina At least one of the following: a. Rest angina – especially between night and early morning b. Marked diurnal variation in exercise tolerance – reduced in morning c. Hyperventilation can precipitate an episode d. Calcium-channel blockers (but not β-blockers) suppress episodes 2. Transient ischemic ECG changes Any of the following in at least two contiguous leads during spontaneous episode: a. ST segment elevation ≥0.1 mV b. ST segment depression ≥0.1 mV c. New negative U waves
RkJQdWJsaXNoZXIy MTk4NDMw