Relationship between Slow Coronary Flow and Left Atrial Appendage Blood Flow Velocities

Plasma factor XI and XII activity in patients with slow coronary flow

The exact pathophysiology of slow coronary flow (SCF) phenomenon, characterized by delayed opacification of coronary arteries during coronary angiography, is still unknown, although endothelial dysfunction, inflammation, vasomotor disorders and atherosclerosis are shown. The present study was conducted to investigate whether there is a coagulation pathway abnormality in patients with SCF measuring plasma factor XI and XII activity. The study included 55 patients with angiographically proven SCF (group I) and 40 individuals with normal coronary flow (NCF, group II). Baseline demographic properties were similar in both groups. Echocardiographic parameters were also similar in patients with SCF and NCF. Factor XI activity was significantly higher in group I when compared with group II. Factor XII activity was also significantly higher in group I when compared with group II (108.9 ± 19 vs. 98.8 ± 20, P = 0.018 and 131.2 ± 17 vs. 119.1 ± 16, P = 0.001, respectively). We conclude that SCF phenomenon appears to be associated with enhanced procoagulant state, which may support the role of inflammation and atherosclerosis in the pathogenesis of this phenomenon.

Impaired cerebral circulation in patients with slow coronary flow

Slow coronary flow (SCF) is characterized by delayed opacification of coronary arteries during coronary angiography and is associated with myocardial perfusion abnormalities, ischemia or myocardial infarction. We hypothesized that SCF could be a part of systemic circulatory abnormalities. Therefore, the present study was conducted to investigate whether cerebral blood flow velocity is altered in patients with SCF. The study included 16 patients suffering from chest pain with angiographically proven SCF and 16 subjects suffering from atypical chest pain with angiographically normal coronary flow. All study subjects were selected among those who undergone routine cardiac catheterization. SCF was defined based on thrombolysis in myocardial infarction frame count that reflects coronary artery flow. Thrombolysis in myocardial infarction frame count was significantly higher in patients with SCF than those with normal coronary flow. The average peak systolic, end diastolic and mean flow velocities of the middle cerebral artery were measured and recorded in both groups by transcranial Doppler ultrasonography. Baseline demographic properties were similar in both groups. Echocardiographic parameters were also similar in patients with SCF and those with normal coronary flow. In contrast, both right and left middle cerebral artery peak systolic, end diastolic and mean flow velocities were significantly lower in patients with SCF than those with normal coronary flow. We conclude that cerebral blood flow velocity is significantly lower in patients with SCF. SCF phenomenon may reflect a part of impaired systemic circulation.