Novel physiological insight into a lotus root appearance in stable coronary artery diseases; Report of two cases.

So far physiological significance of multiple intraluminal channels separated by thin wall structures, so called "a lotus root appearance", in an angiographic insignificant lesion in patients with suspected angina pectoris has remained undetermined. Here we present two cases that showed a "reverse visual-functional mismatch" phenomenon of a lotus root appearance using the indexes of myocardial fractional flow reserve and/or coronary flow velocity reserve. Our findings may provide a novel physiological insight into a lotus root appearance as a high possibility of critical functional stenosis in those with stable coronary artery diseases.