When does a left anterior descending stenosis alter flow across a left main segment?: interpreting left main fractional flow reserve with downstream obstruction.

摘要

Attributed to Albert Einstein, the saying, “Everything should be made as simple as possible, but not simpler,” embodies a concept that certainly applies to our understanding and interpretation of fractional flow reserve (FFR) across the most clinically important stenosis interventionalists encounter, the left main (LM) stenosis. Remarkable technical advances supported by multicenter, long-term outcome studies have validated FFR for daily use in the cardiac catheterization laboratory. FFR, the ratio of coronary pressure beyond a stenosis to the aortic pressure (representing the normal coronary pressure in the absence of a stenosis), measured during maximal hyperemia (ie, minimal myocardial bed resistance) identifies the ischemic potential of the lesion.