Coronary slow flow (CSF) phenomenon, which is characterized by delayed coronary opacification in the absence of obstructive epicardial coronary artery disease, is a relatively common finding in patients undergoing routine coronary angiography and is often associated with chest pain. In some patients with CSF, blood flow may be heterogeneously distributed in the three coronary arteries, suggesting the heterogeneously distributed microvascular dysfunction in the myocardium. However, the vessel heterogeneity of Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) has not been fully elucidated.~P-wave dispersion (PWD) is defined as the difference between the longest and the shortest P-wave duration recorded from multiple different surface electrocardiogram (ECG) leads, and it has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses5, which are well known electrophysiologic characteristics of the atrium prone to fibrillation. Although it is plausible to hypothesize that PWD might be associated with the heterogeneously distributed microvascular dysfunction, and previous studies have demonstrated the abnormal PWD in patients with CSF, the correlation between TFC heterogeneity and PWD has never been evaluated.~In this study, the investigators aimed to investigate the vessel heterogeneity of TFC in the three coronary arteries, and its relation to PWD, in patients with CSF and otherwise normal coronary arteries.
The investigators aimed to investigate the vessel heterogeneity of Thrombolysis in Myocardial Infarction frame count (TFC) in the three coronary arteries, and its relation to P-wave dispersion, in patients with coronary slow flow and otherwise normal coronary arteries.