Patients with severe aortic stenosis combined with severe heart failure often miss the opportunity for surgery, and the prognosis is poor with drug therapy alone.In recent years, the emergence of transcatheter aortic valve replacement (TAVR) has brought new hope for these patients, and since its birth in 2002, TAVR has been widely used internationally, and its safety and efficacy have been confirmed by several large, prospective, randomized controlled studies. Levosimendan is a new type of positive inotropic drug. It not only enhances myocardial contractile force through calcium sensitization, but also activates K+ sensitive channel KATP on the membrane of vascular smooth muscle, relaxes the arteries and veins of the whole body, and reduces the front and back load of the heart, pulmonary vascular resistance and systemic vascular resistance. A series of studies suggested that for patients undergoing thoracotomy in various cardiac surgeries, regardless of whether the patients were accompanied by ventricular systolic dysfunction before surgery, the use of levosimendan resulted in significantly higher postoperative cardiac function and decreased mortality than the control group, and patients with preoperative LVEF \< 40% benefited more. At present, there are no studies to clarify the regulatory effect of levosimendan on cardiac function after TAVR in patients with severe aortic stenosis complicated with cardiac insufficiency. This is a randomized controlled study. On the basis of basic drug therapy, the treatment group was given levosimendan to analyze the regulatory effect of levosimendan on cardiac function after TAVR.