Home > Medical > Heart Health > Overview Overview All sections in Heart » About Heart » Children & Heart Disease » Congenital Heart Disease » Emergency Treatment » FAQs » Diet and your Heart » Health Tips » Heart and Exercise » Heart Attack » Heart Transplants » After a Heart Attack » Multimedia » Heart News » Obesity » Smoking & your Heart » Stress & your Heart » Tests & Procedures » The Heart in Space » Treatment » Women & Heart Disease Learn more about heart health conditions including atrial fibrillation, coronary artery disease, arrhythmia and more in this overview. Arrhythmia An arrhythmia is any deviation from the normal rhythm of the heart. Arrhythmias are important as they cause unpleasant symptoms, which may progress to serious complications. Cardiomyopathy The cardiomyopathies are a group of heart diseases that are defined by myocardial (heart muscle) dysfunction as the initial event. Atrial fibrillation Fibrillation is a rapid and chaotic beating of the many individual heart muscle fibres. load more From our sponsor 3 symptoms of an acute heart failure episode! 5 lifestyle changes to help manage heart failure!