[Abstract] 0bjective : To investigate the relationship between coronary microvascular dysfunction (CMD) and left ventricular systolic function under rest and stress in female patients with non-coronary artery obstruction and ischemic heart disease by two-dimensional speckle tracking technique and transthoracic coronary flow imaging under adenosine stress. Methods: Selected female patients with suspected symptoms of angina pectoris and coronary artery stenosis less than 50% in the past 3 months were examined by transthoracic coronary flow imaging (TTDE) under adenosine load. According to the coronary flow velocity reserve (CFVR) measured by TTDE

the selected people were divided into two groups: CFVR < 2.0 group (n = 26) and control group (n = 33). Routine echocardiography and two-dimensional speckle tracking imaging were performed at rest and adenosine load.The difference between the left ventricular global longitudinal strain (GLS) under load and the GLS at rest is the global left ventricular systolic reserve (ΔGLS). The parameters of routine echocardiography and Δ GLS in resting state were compared between the two groups. Results:The age

systolic and diastolic blood pressure under adenosine stress

resting heart rate

proportion of diabetes

hypertension and hyperlipidemia in the case group were significantly higher than those in the control group (P＞0.05

Table 2). The GLS andΔGLS under adenosine stress in the case group were significantly lower than those in the control group (P< 0.05

Table 2). Correlation analysis showed that CFVR was correlated with resting heart rate（r=-0.378）

GLS （r=0.320）and ΔGLS（r=0.615） under hyperemia (P< 0.05

Table 3). After adjusting the influencing factors of age

diabetes

hypertension

hyperlipidemia

systolic and diastolic blood pressure

resting heart rate and GLS during hyperemia by multiple linear regression analysis

CFVR andΔGLS were still independently correlated (P<0.05

β=0.906

Table 3). Conclusion: CMD is associated with GLS reserve in female patients with non-obstructive ischemic heart disease

and the lower the CFVR

the worse the systolic reserve function of LV. Speckle tracking combined with transthoracic coronary flow imaging can early evaluate the left ventricular systolic reserve function of CMD in female patients with non-obstructive ischemic heart disease.