Distinction & description of terms
Distinction & description of terms:
1-Cardiac Syndrome X is now understood as Microvascular Angina, a subtype of INOCA.
2-INOCA (Ischemia with No Obstructive Coronary Artery disease) is the modern, broader preferred term because it reflects true ischemia with clear pathophysiology, not just normal angiograms.
3-So cardiac Syndrome X (older term) described patients—often women—with: chest pain, normal coronary arteries, and positive stress tests. It was once thought to be non-cardiac but later linked to microvascular dysfunction.
4-INOCA is a broader, structured term used in current guidelines (AHA, ESC) and includes:
1-Microvascular angina (replaces Syndrome X)
2-Vasospastic (variant) angina without blockage
3-Other non-obstructive causes of ischemia
