EDN1 and coronary artery disorder: Previously, intravenous administration of BQ-123 to anaesthetised pigs and, via intracoronary injection, to a small sample of human patients with coronary artery disease has been reported not to alter AV nodal conduction [49], [50], suggestive of a lack of effect of basal endogeneous ET-1 on AV nodal conduction via ETA receptors in those studies.