The relationship between myocardial perfusion and left ventricular longitudinal systolic function in patients with coronary slow flow

Abstract

Objective To investigate whether myocardial perfusion impairment and left ventricular(LV) longituadinal systolic dysfunction had happened in patients with coronary slow flow(CSF), and to assess the relationship between them by myocardial contrast echocardiography(MCE) and speckle tracking imaging(STI). Methods A total of 55 patients underwent coronary angiography for angina were enrolled, of those 35 with coronary slow flow phenomenon as CSF group, 20 patients with normal coronary angiography as control group. STI and MCE were performed from the apical 4-, 3-and 2-chamber views at baseline and after low-dose dobutamine stress echocardiography (LDDSE) in CSF group and control group. STI derived LV global longitudinal strain(GLS) and GLS amplitude of variation(ΔGLS), and MCE derived myocardial blood flow(MBF), and myocardial flow reserve(MFR) were obtained. And the correlation between GLS/ΔGLS and MBF/MFR was analyzed. Results At baseline, the GLS and MBF were similar between CSF group and control group(P>0.05). After LDDSE, both GLS and MBF were significantly increased in two groups(P<0.05). The GLS, ΔGLS, MBF, and MFR in CSF group were significantly lower than those in control group(P<0.05). There was no significant correlation between GLS and MBF at baseline in the CSF group(r=-0.274, P=0.111). However, after LDDSE significant correlation existed between GLS and MBF(r=-0.630, P=0.000). Conclusions LV longituadinal systolic function is impaired in patients with CSF under dobutamine stress test, the impairment of MBF and MFR could be an important contributor to the decrease of LV longituadinal systolic function. Key words: Echocardiography; Microbubbles; Dobutamine; Coronary disease; Ventricular function, left; Speckle tracking imaging