A design approach is a general philosophy that may or may not include a guide for specific methods. Some are to guide the overall goal of the design. Other approaches are to guide the tendencies of the designer. A combination of approaches may be used if they don't conflict.
Bradycardia can be caused by: 1  Changes in the heart that are the result of aging. 2  Diseases that damage the heart's electrical system. These include coronary artery disease, heart attack, and infections such as endocarditis and myocarditis. 3  Conditions that can slow electrical impulses through the heart.
Healthy young adults and athletes often have heart rates of less than 60 beats a minute. In other people, bradycardia is a sign of a problem with the heart's electrical system. It means that the heart's natural pacemaker isn't working right or that the electrical pathways of the heart are disrupted.