Dr. Zhang has been engaged in cardiac surgery for 19 years, focusing on the surgical treatment of coronary heart disease and atrial fibrillation. The basic research of atrial fibrillation is at the leading level. In 2006, he went to the Cardiothoracic Vascular Surgery Department of the Saint Joseph Hospital in Marseille, to study cardiac surgery techniques. In 2011, he went to the Cardiac Surgery Department of the Rangueil Hospital affiliated to the Sabatier University in Toulouse, to study minimally invasive valve surgery, aortic dissection surgery, TAVR surgery and hybrid cardiovascular surgery.