Percutaneous Coronary Intervention (PCI) Enhances the Amplitude of the Early Diastolic Suction Wave in the Treated Artery

Abstract

Background: Coronary flow is critically dependent on suction developed by the myocardium in diastole and left ventricular ejection during systole, both of which accelerate flow. Wave intensity analysis enables quantification and separation of these forces. The impact of (PCI) on the coronary wave intensity (CWI) profile is unclear. Methods: We performed simultaneous intracoronary pressure and velocity measurements in 17 patients undergoing elective PCI. Measurements were made distal to the target lesion prior to and following PCI during adenosine induced hyperaemia. Coronary wave speed (SPc) was calculated utilising the “single point sum-of-squares” method. Wave intensity profiles of ensemble averaged cardiac cycles were constructed applying previously described equations. The peak intensities of the dominant forward travelling “pushing” wave (Wave 2) and the dominant backward travelling “suction” wave (Wave 5) were calculated prior to and following PCI. Results: CWI profiles demonstrated the previously described six major waves. PCI resulted in substantial increases in peak intensity of Wave 2 and Wave 5 (mean increases in peak intensity of 227% p = 0.0007 and 170% p = 0.0005, respectively). Significant decreases were seen in SPc distal to the lesion following PCI (p = 0.003) and with intracoronary adenosine (p = 0.0003). Conclusion: PCI appears to augment both the forward travelling “pushing” wave and backward travelling “suction” waves. These findings are consistent with the enhancement of coronary flow seen with PCI. The decrease in wave speed following PCI and intracoronary adenosine may be explained by an increase in coronary diameter induced by increased flow.