Scaramucci was the first to consider the effects that the contracting heart had on coronary arteries and on coronary blood flow in 1696.1 However, it was more than 250 years later that Gregg and Sabiston reported experimental evidence in a landmark paper which described phasic coronary flow.2 They described how the contracting heart muscle behaves as a “throttling mechanism and impedes coronary flow” by compression of the myocardial vascular bed.