Electrocardiographic changes in patients with haemorrhagic fever with renal syndrome

The purpose of the study was to assess the incidence, type and dynamics of electrocardiography (ECG) alterations in patients with haemorrhagic fever with renal syndrome (HFRS) according to different stages of the disease. 79 patients hospitalized at the University Hospital for Infectious Diseases in Zagreb during the large HFRS outbreak in Croatia in 2002 were retrospectively analysed. HFRS diagnosis was confirmed by enzyme-linked immunosorbent assay. A 12-lead resting ECG was obtained. 30 (38%) patients had abnormal ECG findings, most frequently in the oliguric stage. Increased levels of urea and creatinine were observed in all patients with abnormal ECG, along with abnormal chest X-ray in nearly 50% of cases. Sinus tachycardia was the most frequent ECG disorder in the febrile stage, and bradycardia in the oliguric stage. During the course of disease, some other ECG disorders were recorded: bundle branch conduction defects, non-specific ventricular repolarization disturbances, supraventricular and ventricular extrasystoles, prolonged QT interval, low voltage of the QRS complexes in standard limb leads, atrioventricular block first-degree, and atrial fibrillation. Myocarditis was present in 3 patients. In conclusion, abnormal ECG was found in more than one-third of HFRS patients with the most common findings during the oliguric stage. All ECG changes were transient.