The state of systolic and diastolic functions of the left ventricle and heart rate variability in patients with atrial fibrillation after infection of COVID-19

Abstract

Abstract Introduction It is known that atrial fibrillation (AF) is one of the most common arrhythmias in patients (pts) who have had a COVID-19 infection (CI). The aim of our study was to evaluate systolic and diastolic functions of the left ventricle (LV) and heart rate variability (HRV) in pts with AF depending on the past CI. Research material and methods 131 pts with paroxysmal or persistent forms of AF in sinus rhythm were studied. 93 people had a history of an average of 6.2±0.5 months ago of COVID-19 infection. They made up the 1st group of examined pts. The remaining 38 patients did not have a history of this infection. They constituted the 2nd group of the study group, which was the control group. Transthoracic echocardiography and Holter monitoring ECG were performed according to the standard technique. Results of the study We did not find any difference in hemodynamic parameters characterizing the systolic function of LV. So, the values of the end-diastolic volume (117.0±7.6 mm and 116.0±7.2 mm), end-systolic volume (55.7±4.9 mm and 55.2±4.7 mm) and ejection fractions (55.0±2.1% and 54.4±2.0%) in the groups did not differ significantly. However, statistical significance was obtained in indicators characterizing LV diastolic function. So, significantly different flow rates in the 1st and 2nd groups of pts – E (60.8±1.63 sm/s and 94.6±2.97 sm/s, p<0.001), A (61.8±0.83 sm/s and 73.1±1.03 sm/s, p<0.001), their E/A ratios (0.98±0.02 and 1.39 + 0.03, p<0.001) and DE score (175.9±2.20 ms and 202.5±4.03 ms, p<0.001). A more significant violation of LV diastolic function after CI led to an increase in the diameter of the left atrium (LA) (4.99±0.14 cm in the 1st group compared with 4.40±0.004 sm in the 2nd group, p<0.001) and LA index (46.4±0.011 sm in the 1st group compared with 42.93±0.08 in the 2nd group, p<0.001). We also found a significant difference in such indicators of HRV between groups “1” and “2” as – SDANN (102.7±2.33 and 151.7±1.23 ms, p<0.001), SDNN (124, 3±4.06 and 181.3±4.83 ms, p<0.001), and RMSSD (100.4±4.57 and 173.2±13.51 ms, p<0.001). Conclusion In pts with AF, after undergoing CI, the LV diastolic function begins to suffer first, which leads to an increase in the size of the LA. Pts after CI also had a change in the autonomic regulation of the heart rhythm, and as a result, an increase in the electrical instability of the atria. Funding Acknowledgement Type of funding sources: None.