Coronary flow velocity at rest: a speed limit for a safe prognostic journey?

The study presented by Zagatina and co-workers in the present issue of the Journal raises an interesting issue. Coronary flow velocity at rest is usually associated with dynamic assessment during stress but it may also have an important pathophysiologic and prognostic meaning when evaluated at rest, before stress. This is new, apparently surprising and counterintuitive. However, at a closer look it fits well with the pathophysiological background and initial preliminary clinical experience available in this important but still largely unexplored field.