Assesment of left atrial function in patients with coronary slow flow

Background: Coronary slow flow phenomenon (CSFP) is the slow transmission of the opaque solution to the distal portion of the coronary artery in the absence of the obsructive coronary lesions. The pathogenesis of the CSFP is not completely understood, but microvascular ischemia may shown as a cause, which is te result of the decrease vazodilator reserve. The aim of this study is to determine the effect of CSFP to the left atrial functions. Material and methods: We chosed the patients who were admitted to our hospital with angina pectoris between january 2013 and november 2014. A total of the 50 patients with angiographically proven CSFP and 40 controls with normal coronary arteries were included in the study. The demografic and clinical features in two groups were similar. We performed coronary angiography to all patients with standard Judkins technic. TIMI frame count was used for the determine of CSFP. Left atriyal functions was measured with the transthorasic apical four chamber view with ecocardiography device(GE VIVID S6). Left atrial volumes were measured with modified simpsons methods, mitral E, A, E/A ratio with pulse wave Doppler , Em and Am with tissue Doppler. Results: E (0.09±0.19; 0.12±0.02, p<0.001), Em/Am (0.83±0.19; 1.2±0.29, p<0.001), E/A (0.99±0.2; 1.1±0.28, p<0.001) was lower in coronary slow flow (CSF) group than kontrols. E/Em was higher in CSF group than controls (7.1±2.1; 5.9±1.3, p=0.003). SAVImax (16.6±4.6, 11.3±2.1, p<0001), SAVImin (6.4±3.3, 5.0±1.3, p=0.001), SAVIpreA (12.8±2.8, 6.8±2.6, p<0.001) was higher in CSF group. In CSF group, passive emptying volume and its fraction was lower, although active emptying volume and its fraction was higher than controls. There was a significant relationship between SAAEF and diastolic parameter E/A (r=-0.4, p=0.003).There was a significant relationship between frame LAD and SAAEF, mean frame and SAAEF (r=0.6, r=0.34, p<0.001, p<0.001, respectively). Conclusions: İn our study, we showed the relationship between left atrial volume and LV diastolic disfunction in patients with CSFP. As a result, significant changes occur in left atrial volumes and active atrial volume increases in patients with CSFP. These results signifies the importance of maintaining sinus rythm in patients with CSFP. Our study showed that CSFP is not innocent and LV diastolic functions should be evaluated in CSFP patients. We need larger prospective studies for treatment and prognosis. Keywords; Coronary slow flow, left atrial functions, left ventricular diastolic disfunction