The effect of essence of Citrus aurantium on the electrophysiological properties of isolated perfused rabbit AV-node

Pharmacological studies and traditional medical literature point to the cardiovascular effects of the Citrus aurantium L. (Rutaceae) in many instances. In the present study, we used isolated perfused AV-node of rabbit as an experimental model to determine the effect of various concentrations of essence of Citrus aurantium (0.1-0.3 v/v) on electrophysiological properties of isolated heart. The second goal of the present study was to assess the protective role of essence of Citrus aurantium on arrhythmogenic effects of ouabain. This was a semi-experimental study. We used isolated perfused rabbit AV-nodal preparation, in three groups. In the first group, the effect of various concentration of the Citrus aurantium (0.1, 0.2, 0.3 ml/l) was assesed on the AV-node. In the second and third groups, the effect of Citrus aurantium was tested in the presence of ouabain (0.1?molar) and verapamil (0.1?molar). We used 6 rabbit in each group. Statistical analysis was preformed by SPSS Mean±SE was used in the all results. Our results showed depressant effects of extract of Citrus aurantium on Wenchebach Cycle Length (WBCL), AV Conduction Time (AVCT), Effective and Functional Refractory Periods (ERP & FRP). Rate-dependent properties such as Facilitation and fatigue significantly increased by Citrus.a (0.3ml/l). We had significant increase in the AVCT (32.6±3.6 to 40±6.08 msec) and FRP (147±5.1 to 166.6±3.6 msec) by Citrus.a. We had a protective role of Citrus aurantium on ouabain induced AV-nodal depression. The magnitude of facilitation and fatigue in the concentration of 0.3 C.aurantium was 7.5±0.3 and Conclusion6.5±0.5, respectively. The above results indicated potential inhibitory and antiarrhythmic effect of Citrus aurantium in treating supraventricular tachyarrhythmia.