[Changes of 24-h Holter monitor recordings in association with interferon alpha therapy for chronic hepatitis C].

: We examined cardiovascular complication of interferon (IFN) therapy in 23 patients with chronic hepatitis C who did not have cardiac disease prospectively. Twenty four-h Holter monitor recordings were performed before and during IFN therapy. Seven of these patients (30%) showed abnormalities on their 24-h Holter monitoring recordings. Premature ventricular contraction (PVC) occurred in two patients, intermittent WPW syndrome in one, and ST-T change in four. Only one patient with PVC complained of palpitation. These complications were not severe and immediately after IFN therapy was stopped. There was no correlation between Holter ECG abnormalities and sex, age, quantity of HCV, or 2-5 oligoadenylate synthetase activity. It was suggested that cardiovascular complications caused by IFN therapy occurred more frequently than expected. However, diagnosis of these complications is difficult because most patients have no subjective symptoms and there is scarcely any change in laboratory test results. Careful observation of patients may be required during IFN therapy regardless of cardiovascular symptoms.