Acute coronary syndrome (ACS) comprises a spectrum of clinical conditions which initiated by rupture of an atherosclerotic coronary plaque with overlying acute thrombosis.Recent research in the last decade has changed our view ACS from a mere lipid deposition to an inflammatory disease; from ACS exclusively due to plaque rupture to the novel definitions of plaque erosion or calcified nodule; from the notion of a superimposed thrombus with necessary lethal consequences to the concept of healed plaques and thrombus contributing to plaque progression. The coronary thrombus may be completely occlusive, as is frequently seen in ST-segment elevation myocardial infarction (STEMI), or non-occlusive, as can be observed in unstable angina or non-ST-elevation myocardial infarction (UA/NSTEMI). Thrombus on preexisting plaque, dynamic obstruction from coronary spasm or Prinzmetal’s angina, progressive mechanical obstruction, inflammation and/or infection, and secondary unstable angina due to global myocardial oxygen supply and demand mismatch. Slow coronary flow (SCF) phenomenon is a coronary microvascular disease diagnosed by detection of delayed dyeopacification in coronary arteries during an angiography in the lack of obstructive coronary artery disease. The incidence of SCF has been reported to be approximately 1-7% in patients who undergo a diagnostic coronary angiography due to suspected coronary artery disease.In the absence of substantial epicardial coronary stenosis, the coronary slow flow phenomenon (CSFP) is an angiographic clinical entity defined by delayed distal artery opacification. The extensive usage of ECG markers in numerous therapeutic contexts may be influenced by P-wave inscriptions.Thus, the aim of the present study to review coronary flow phenomenon in patients with acute coronary syndrome

Plaque Progression; Slow Coronary Flow Phenomenon; Acute Coronary Syndrome