Coronary artery ectasia (CAE) has been defined as localized or diffuse dilatation of epicardial coronary arteries more than 1.5 fold of adjacent normal segments. Isolated CAE constitutes minor portion of the total CAE cases, with an incidence of 0.1% to 0.79% in which coronary artery stenosis or severe valvular heart diseases are not present. CAE represents not only an anatomical variant but also a clinical constellation of coronary artery disease (CAD) like association with myocardial ischemia and acute coronary syndromes. Patients with CAE without significant coronary narrowing may still present with angina pectoris, positive stress tests, or acute coronary syndromes. Impaired epicardial and microvascular perfusion were demonstrated in ectatic coronary arteries.