Coronary artery ectasia is a rare angiographical finding, and it accounts for less than 5% of all coronary angiograms. We report a case of a 55-year-old male patient who presented with fatigue and exertional chest pain. Paraclinical tests revealed cardiac ischemia and sinus node dysfunction, as well as coronary artery ectasia without significant coronary stenosis. Factors involved in cardiac ischemia in this context comprise slow flow, poor collateral circulation, microcirculatory dysfunction, lack of adequate exertional coronary vasodilatation, and endothelial dysfunction. Moreover, poor collaterals with rudimentary sinus node artery may explain sinus node dysfunction. Discussion is made in light of the relevant medical literature.