Objectives The abnormal prolongation in QT interval in diabetics reflects the electric instability of heart, which is related to the incidence of cardiac arrhythmia. As one of the frequently used antibiotics in clinical practice, Levofloxacin may prolong QT interval, or even lead to lethal ventricular arrhythmia - torsade de pointes (Tdp). The present study was to assess the arrhythmogenic effect of Levofloxacin on diabetic rabbits.
Methods 30 healthy New Zealand rabbits weighing 2.0-2.5 kg were randomised into the control group (n = 10) and the test group (n = 20). The test group was injected with 5% tetraoxypyrimidine in a dosage of 160 mg/kg via the marginal vein to establish the diabetic rabbits model, while the control group was injected with the same dosage of saline. The arterially perfused rabbit ventricular wedge preparations were produced four weeks later, which were infused with Levofloxacin (1.14 mg/ml), and transmural ECG and action potential period from both endocardium (APDEndo) and epicardium (APDEpi) were simultaneously recorded.
Results The QT interval, APDEndo and APDEpi,, andtransmural dispersion of repolarization (TDR) of diabetic rabbits was prolonged, the incidence rate of early after-depolarisation (EAD) and ventricular fibrillation (VF) increased (P < 0.05). After perfusion with Levofloxacin, the QT interval, APDEndo and APDEpi, TDR were longer, the incidence rate of EAD and VF were more increased in control and test group (P < 0.05).
Conclusions In comparison to the control group,ventricular arrhythmia was liable to be induced after Levofloxacin perfusion in the diabetic group.