Layer-specific analysis of left ventricular myocardial contractility in patients with coronary slow-flow phenomenon

PURPOSE: Coronary slow-flow phenomenon (CSFP) is an angiographic diagnosis characterized by delayed coronary opacification in the absence of significant epicardial coronary stenosis. We previously reported impaired left ventricular (LV) function in patients with CSFP. However, the LV wall comprises three myocardial layers whose contractility can be differently affected. Therefore, we evaluated layer-specific (endocardial, mid-myocardial, and epicardial) LV myocardial contractility and assessed its relationships with the number of affected coronary arteries and their flow. METHODS: We studied 60 patients with CSFP and 46 controls. CSFP was diagnosed by thrombolysis in myocardial infarction frame count. Echocardiography was performed within 72 hours after the coronary angiography. LV layer-specific longitudinal strain (LS) was measured using two-dimensional speckle-tracking echocardiography. RESULTS AND CONCLUSIONS: The LS of all three myocardial layers was lower in patients with CSFP than in controls. In patients with CSFP, LS of all three myocardial layers and transmural LS gradient correlated negatively with the number of affected coronary arteries and the mean thrombolysis in myocardial infarction frame count.