Left main (LM) lumen diameters >4 mm are the norm and diameter >4.5 mm is present in almost 50% of patients by intravascular ultrasound (IVUS). Normal LM minimum lumen area averages 14.1 mm2 for women and 16.2 mm2 for men, requiring an area stenosis of 57-63% for LM lesion to be hemodynamically significant using the prevailing criterion of 6 mm2 as a cut-off for revascularization. Incomplete LM visualization with IVUS is common (68%) without dedicated and specific LM IVUS techniques.
© 2019 Wiley Periodicals, Inc.