Benzopyran derivatives are the potassium channel openers (KCOs) having antihypertensive, cardio-protective,
myocardial protectors, powerful peripheral vasodilators and anti-ischemic activity. Their usage as anti-ischemic including
angina, hypertension and diabetes is thought to be due to the stimulation of KATP channels which are contemplated to
produce vasorelaxation and myocardial protection. It is observed that potassium channels are involved in mediating the
cardio-protective effects of pre-conditioning in animal models and man. KCOs protect heart from an ischemic insult
without contribution from vasodilatation. This review provides an overview of the characteristics of KCOs and their
actions on subtypes used widely for the treatments of various diseases including hypertension, cardiac ischemia,
arrhythmia, smooth muscle relaxation, diabetes, cardio-protective and anti-angiogenic activities.