specialty internal medicine cardiologist united states three year residency internal medicine followed three year fellowship cardiology possible specialize sub specialty recognized sub specialties united states acgme cardiac electrophysiology echocardiography interventional cardiology nuclear cardiology recognized subspecialties united states american osteopathic association bureau osteopathic specialists aoabos include clinical cardiac electrophysiology interventional cardiology india person needs undergo three years residency general medicine pediatrics mbbs three
Applied science Medicine and health Internal medicine Cardiology