Donald J. Hagler, M.D., primarily studies the use of echocardiography and interventional cardiac catheterization procedures in the management of complex congenital heart disease. His work taps into the long history of congenital cardiac surgical and medical teamwork at Mayo, which provides the background and basis for clinical research investigating the optimal management of complex congenital heart disease.

Dr. Hagler participates in interventional catheterization studies to determine the effectiveness of atrial and ventricular septal defect closure devices, percutaneously implantable tissue prosthetic valves, and pulmonary artery stenting procedures.