Background and purpose: Cannabidiol (CBD) is a phytocannabinoid, with anti-apoptotic, anti-inflammatory and antioxidant effects and has recently been shown to exert a tissue sparing effect during chronic myocardial ischaemia and reperfusion (I/R). However, it is not known whether CBD is cardioprotective in the acute phase of I/R injury and the present studies tested this hypothesis. Experimental approach: Male Sprague-Dawley rats received either vehicle or CBD (10 or 50 mg·kg-1 i.v.) 10 min before 30 min coronary artery occlusion or CBD (50 mg·kg-1 i.v.) 10 min before reperfusion (2 h). The appearance of ventricular arrhythmias during the ischaemic and immediate post-reperfusion periods were recorded and...