Investigation of heart rate variability and ventricular repolarization indexes in brucella patients with palpitations

Objective: Brucellosis is the most common zoonotic disease in the world, and the resulting disease can include all human organ systems. It has also become a major economic loss and public health problem, including in developing countries. Tp-e interval and Tp-e / QT ratio have been accepted as new markers in the evaluation of myocardial repolarization and ventricular arrhythmogenesis. Previous studies have focused on the interpretation of the low frequency (LF) and low / high frequency (LF / HF) ratio to demonstrate sympathetic cardiac control and autonomic balance. In this study, we aimed to investigate the relationship between heart rate variability parameters (HRV) and venticular repolarization indices in patients with brucellosis, and to observe the effect of brucella on the autonomic nervous system and to understand whether it is predisposed to arrhythmia. Material and Method: This study was carried out in the Department of Cardiology in Adıyaman University Training and Research Hospital between January 2019 and January 2020. In our study, the results of 24-hour holter and electrocardiography were examined in 50 brucellosis patients and 50 control groups who applied to the Adıyaman University Training and Research Hospital Cardiology Department polyclinic with palpitations. Heart rate variability, time and frequency indices of the two groups were compared. Adjusted QT (QTc), Tp-e dispersion, Tp-e interval, corrected Tp-e and Tp-e / cQT ratio were measured from 12-lead electrocardiograms. These parameters were compared between groups. Results: The study included 50 patients with brucellosis and 50 healthy controls. The rate of males in the brucellosis group was 56% and in the control group it was 46%. Except for QTd measurement, all echocardiographic repolarization parameters were higher in the brucella (+) group than the control group (p <0.005). There was no difference between the groups in terms of time domain indeces in the heart rate variability of the study group (p> 0.005). From the frequency analysis, both daytime and nighttime LF / HF ratios were higher in the brucella (+) group (p <0.001). Both day and night LF / HF ratios were strongly associated with Tpe_cQT (r = 0.700, p <0.001 and r = 0.746, p <0.001, respectively). Conclusion: Our study showed that the ratio of Tp-e dispersion and Tp-e / cQT, which were evaluated electrocardiographically in patients with brucellosis, was prolonged in brucellosis patients. These results may be indicative of subclinical cardiac involvement in brucella patients. Systemic infectious diseases such as brucella are related to variable sympathovagal balance, and an increased LF / HF ratio may be indicative of sympathetic system dominance in brucella patients. For this reason, such infectious diseases should be followed more closely in terms of ventricular arrhythmias in our opinion