AbstractA comparative study of 16 flavones was carried out using 4 experimental models: 1, hyperkinetic ventricular arrhythmias induced by reperfusion in rat isolated heart; 2, arrhythmias following coronary artery ligation‐reperfusion in anaesthetized guinea‐pig; 3, pytressine arrhythmias by coronary spasm in anaesthetized guinea‐pig; and 4, anti‐ischaemic activity using anex vivoperfusion heart technique after coronary occlusion in guinea‐pig. The structure effect relationships of flavone, 3‐hydroxyflavone, 6‐hydroxyflavone, 7‐hydroxyflavone, 6,7‐dihydroxyflavone, 7,8‐dihydroxyflavone, apigenin, apiin, diosmin, 5‐hydroxyflavone, luteolin, luteolin glycoside, orientin, pratol, rhoifolin, vitexin, tested as antiarrhythmic and anti‐ischaemic agents were compared to lidocaine and verapamil at equimolar doses. The results obtained demonstrated that most of these compounds exerted a protective effect against coronary‐spasm and coronary‐ligation induced ischaemic crisis, and against the ischaemic and the post‐ischaemic arrhythmias. The potencies were found to be structurally depe