Relation of heart rate variability, electrocardiographic changes and serum galectin 3 levels in patients with coronary slow flow

Aim: Inflammation, endothelial dysfunction and coronary microvascular dysfunction are known as the most responsible pathophysiological mechanisms in coronary slow flow (CSF) and can cause ischemia-related clinical manifestations. In addition, independent of the underlying mechanism, some changes in electrocardiography and laboratory parameters that may be associated with ischemia and ventricular heterogenity can be observed in CSF. In this study, It is aimed to investigate electrocardiographic changes, heart rate variability parameters and serum Galectin-3 (Gal-3) levels in order to show possible ischemia-related fibrosis in CSF. Method: Forty five patients who were determined CSF in coronary angiography (CA) and 40 patients with normal coronary artery (NCA) as a control group were included into the study. Blood samples for routine biochemical tests, complete blood count and serum Gal-3 levels were collected after 12 hours fasting from all patients. Additionally electrocardiographic parameters were also evaluated and 24 hour holter electrocardiography records were obtained for heart rate variability analysis. Results: CSF was more frequent in men (67,4% p=0.007) and with higher body mass index (BMI), (Mean BMI 29,6 kg/m2 in the NCA group and 31,8 kg/m2 in the CSF group, p=0,02). There was no significant difference between the two groups in terms of smoking and drug use. Although PR distance was found to be significantly longer among the electrocardiographic parameters in CSF group. (p=0,038) There was no significant difference between the two groups in the other parameters (QT distance, QTc distance, QTc dispersion, Tp-e, Tp-e / QT ratio, Tp-e / QTc ratio, ST segment depression, fragmented QRS (f-QRS), J wave etc). Similarly, heart rate variability parameters (mean heart rate, mean RR (ms), SDNN (ms), RMSSD (ms), SDNN index (ms), SDANN index (ms), PNN50 (%), VLF (Msec2), HF (msec2), LF / HF ratio, etc.) and serum Gal-3 levels were not significantly different between the groups. Conclusion: The results obtained in this study were not consistent with findings in the literature regarding electrocardiography and heart rate variability parameters associated with CSF. Serum Gal-3, a cardiac fibrosis biomarker previously not studied in CSF, could not be correlated with CSF in this study as well. However, it is concluded that these results may change when a wider group of patients are studied with and additional methods (intravascular ultrasound (IVUS) and optical coherence tomography (OCT) etc.) that can evaluate coronary circulation more objectively are used. Key Words: Electrocardiography, Galectin-3, Heart Rate Variability, Coronary Slow Flow