Left Atrial Dysfunction in Patients with Coronary Slow Flow

Abstract

Coronary slow flow phenomenon (CSFP) is not an infrequent angiographic finding in patients scheduled for coronary angiography. The incidence varies from 1% to 5.5% [1-3], although some cardiologists believe it is often underrecognized, its incidence could be as high as 34% [4]. The CSFP was firstly described by Tambe in 1972 in 6 subjects presenting with chest pain syndromes [5], and now it attracted intensive attention among interventional cardiologists since its original description. The current adapted diagnostic criteria was proposed by John Beltrame in 2012 [6] where CSFP is defined as delayed distal vessel opacification of contrast in the absence of significant epicardial coronary stenosis (coronary artery stenosis ≤40%), with the Thrombolysis in Myocardial Infarction (TIMI) blood flow grade of 2 or corrected TIMI frame count (cTFC) of greater than 27 frames in one or more epicardial vessel. Currently, it’s believed that CSFP is not just a simple angiographic curiosity, it has significant implications in clinical setting. Its pathophysiological mechanism remains unclear, although several possible mechanisms were proposed. In this article, we will summarize the clinical implications, possible mechanisms, and the alteration of cardiac function, especially the changes of left atrial functions in patients with CSFP according to our research and existing literature. Our purpose is to provide further insight into its clinical significance and pathophysiological mechanisms.