Page 71 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax

The Doppler flow wire in acute myocardial infarction
microcirculatory interactions in the coronary circulation. Although promising, WIA has not yet been tested in the setting of acute MI.28
Summary
Microvascular obstruction after acute MI has been associated with ventricular arrhythmias, adverse ventricular remodelling and poor clinical prognosis.4 5 10 Based upon coronary angiography, the incidence of inadequate myocardial reperfusion or a no-reflow phenomenon was approximately 4 15%.8 The results of non-invasive diagnostic techniques such as MCE and contrast-enhanced CMR yielded a higher incidence rate of up to 70% with
CMR.4 5 10 Characteristic findings by intracoronary Doppler flow velocity measurements such as a reduced CFVR secondary to an impaired hyperaemic blood flow velocity, and, in particular, systolic flow velocity reversal and a short diastolic deceleration time, are associated with the presence of microvascular obstruction on MCE and contrast-enhanced CMR. An abnormal CFVR is strongly associated with reduced recovery of left ventricular function after MI.19 22
In primary PCI, the Doppler flow guidewire identifies patients with apparently restored epicardial flow but impaired reperfusion at the myocardial microcirculatory and tissue level. Such patients may benefit from adjunctive treatments such as intracoronary administration of streptokinase, which was recently found to have beneficial effects on infarct size, left ventricular volumes and left ventricular ejection fraction.29
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