Cediran is a cardiac drug in the digitalis class and can be used in clinical practice to treat left heart failure, especially in chronic heart failure combined with atrial fibrillation. In addition, it can also be used to treat arrhythmia. Sometimes, with Sidiran, atrial fibrillation cannot be converted to sinus rhythm. However, it can control the ventricular rate of patients with atrial fibrillation and prevent the heart rate from being too fast. Besides, digitalis can also convert atrial flutter to atrial fibrillation and then play the role of anti-atrial fibrillation, and some patients with valvular disease are also very suitable for such drugs as cediran. Relatively speaking, the contraindications of Sidiran are mainly that it cannot be used in patients with severe heart block, as well as hypertrophic obstructive cardiomyopathy. There are also patients, who have simple mitral stenosis, for whom the application of cediran is not recommended.