The Doppler flow wire in acute myocardial infarction.

Contemporary mechanical reperfusion therapy for acute myocardial infarction is aimed at early and complete restoration of myocardial perfusion. However, successful restoration of epicardial blood flow does not guarantee restoration of flow at the myocardial tissue level. The incidence of inadequate myocardial reperfusion after primary percutaneous coronary intervention (PCI) varies from 15-70%, based upon the diagnostic modality used. The Doppler flow guidewire can be used immediately after primary PCI to identify patients with apparently restored epicardial flow but impaired reperfusion at the myocardial microcirculatory and tissue level. Characteristic findings by intracoronary Doppler flow velocity measurements such as a reduced coronary flow velocity reserve, and, in particular, systolic flow velocity reversal and a short diastolic deceleration time are associated with the presence of microvascular obstruction. Detection of microvascular obstruction by the Doppler flow wire directly after primary PCI can identify patients who may benefit from adjunctive therapy after primary PCI.