A cardiologist is a medical doctor who specializes in the diagnosis and treatment of heart-related conditions. There are several other words or phrases used to describe a cardiologist that could be used interchangeably. These include cardiac surgeon, heart specialist, heart doctor, cardiovascular specialist, and cardiac physician. While each of these terms emphasizes a slightly different aspect of a cardiologist's role, they are all used to describe professionals who work with patients to diagnose and treat conditions related to the heart. Whatever term is used, a cardiologist is a vital part of a patient's healthcare team when it comes to managing heart disease, heart attacks, and other heart-related conditions.