Cardiac arrhythmias, conduction system abnormalities, and autonomic tone in patients with brucellosis

Arrhythmias can occur because of cardiac involvement in patients with brucellosis. We investigated the effect of Brucella (Brucella melitensis) on cardiac arrhythmias in patients without pre-existing arrhythmogenic heart disease.

205 patients with sinus rhythm who were diagnosed with brucellosis and 205 healthy controls were enrolled. ECG was performed, and the parameters were recorded for each patient. 24-hour ambulatory ECG (Holter) monitoring was conducted, and the recordings were analyzed. The time-domain heart rate variability (HRV) results were evaluated.

The average age of the group with brucellosis was 28.9±6.4 years, and 57.1% were male. The ECG parameters, including P dispersion (Pd), QT dispersion (QTd), corrected QTd (QTcd), T-peak to T-end (TpTe), and corrected TpTe (TpTec) were longer and TpTe/QT, TpTe/QTc, TpTec/QT, and TpTec/QTc ratios were higher in the study group compared to the control group (p<0.05). Holter monitoring recorded 33 (16.1%) patients in the study group and 3 (3%) in the control group with abnormal rhythms. In the brucellosis group, low frequency (LF), low/high frequency (LF/HF), and the standard deviation of all R-R intervals (SDNN) values, which are known HRV indicators, were substantially different than in the control group (p<0.001).

We can evaluate the silent involvement of the cardiac conduction system in patients with brucellosis using ECG parameters, which is a non-invasive and simple method in terms of feasibility in clinical follow-up.