Application of intracoronary ultrasonography in the study of coronary artery pathophysiology.

Coronary endothelial function, arterial distensibility, and elastic recoil were assessed in various groups of patients using intracoronary ultrasonic (ICUS) imaging. We found evidence of endothelial dysfunction in patients with risk factors for coronary artery disease even before atherosclerosis could be detected angiographically or with sensitive ICUS imaging. There was marked reduction of arterial distensibility in atherosclerotic arterial segments even with minor disease. Distensibility was partially restored in lesions following coronary balloon angioplasty (PTCA) or directional atherectomy (DCA). We also noted significantly greater elastic recoil following PTCA in soft lesions compared with hard lesions. We conclude that the use of ICUS imaging in cardiac catheterization laboratory provides useful information regarding various physiologic parameters. This capability will add new dimensions to the evaluation and management of patients with coronary artery disease.