Coronary artery aneurysm is a focal dilation of a segment of the coronary artery greater than 1.5 times the diameter of an adjacent normal segment.

Coronary artery ectasia is a diffuse dilation in which the length of the dilated segment is greater than 50% of the diameter.

• Until recently, these terms were historically used interchangeably.
• The reported incidence ranges from 0.3%-5%.
• Men are more affected than women.
• The right coronary artery (RCA) is most commonly affected, followed by the left circumflex artery (LCX) and the left anterior descending artery (LAD).

Risk factors / causes:

• Atherosclerosis / coronary artery disease (most common cause in adults)
• Kawasaki disease (most common cause in children)
• Postprocedure (percutaneous coronary intervention [PCI] angioplasty, stent implantation)
• Vasculitides (Takayasu arteritis, systemic lupus erythematosus [SLE], polyarteritis nodosa, rheumatoid arthritis)
• Connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome)
• Infections (bacterial, mycobacterial, fungal, syphilitic, and mycotic infections; Lyme disease, septic emboli, HIV)
• Drug use (cocaine, amphetamines)
• Congenital

Presentation: Most aneurysms are clinically silent and detected incidentally on imaging.

When patients present symptomatically, it is usually due to one of the following complications:

• Atherosclerotic / obstructive disease leads to acute coronary syndrome (ACS)
• Thrombus formation leads to distal embolization / ACS
• Massive enlargement leads to compression of adjacent cardiopulmonary structures
• Aneurysm rupture leads to acute cardiac tamponade
• Stress-induced myocardial ischemia due to microvascular dysfunction