Short answers, pulled from the story.
Cardiology is the branch of medicine that deals with disorders of the heart and the cardiovascular system, and is a sub-specialty of internal medicine. It covers congenital heart defects, coronary artery disease, heart failure, valvular heart disease, and electrophysiology. Physicians who specialize in cardiology are called cardiologists.
Helen B. Taussig (1898-1986) is recognized as the founder of pediatric cardiology. She became famous through her work on Tetralogy of Fallot and collaborated with Alfred Blalock and Vivien Thomas at Johns Hopkins Hospital to develop the Blalock-Taussig Shunt, a surgical procedure for treating cyanotic newborns known as blue babies.
In the United States, becoming a cardiologist requires at least six years after medical school: a three-year internal medicine residency followed by a three-year cardiology fellowship. Further sub-specialization, such as clinical cardiac electrophysiology, requires additional training and takes eight years after medical school total.
Coronary artery disease is the most common type of cardiovascular disease and the leading cause of death globally in 2013, resulting in 8.14 million deaths (16.8% of all global deaths). In the United States in 2010, about 20% of people over 65 had coronary artery disease, compared to 7% among those aged 45 to 64 and 1.3% among those aged 18 to 45.
The Blalock-Taussig Shunt is a surgical procedure used to treat Tetralogy of Fallot, the most common congenital heart disease, arising in 1-3 cases per 1,000 births. The modified version places a graft between the subclavian artery and the ipsilateral pulmonary artery to restore correct blood flow in newborns whose deoxygenated blood bypasses the lungs.
Interventional cardiology is a branch of cardiology that treats structural heart diseases using catheter-based procedures rather than open surgery. Procedures include angioplasty, stent implantation, transcatheter aortic valve implantation (TAVR), and MitraClip, all performed by threading a catheter through the femoral or radial artery under X-ray visualization. Primary angioplasty is now the gold standard of care for an acute myocardial infarction.