ATEN 50MG contains Atenolol which belongs to the group of medicines called beta-blockers. It is used in the treatment of high blood pressure (hypertension) and arrhythmia (uneven heart beats). High blood pressure (hypertension) is a condition in which the blood exerts an increased pressure against the walls of blood vessels. If left untreated, it may lead to damage of blood vessel, kidney problems, stroke and other heart problems. Arrhythmia is a heart condition in which there is an improper generation or conduction of cardiac impulses which affects the normal cardiac rhythm.