cardiology
From Longman Dictionary of Contemporary Englishcardiologycar‧di‧ol‧o‧gy /ˌkɑːdiˈɒlədʒi $ ˌkɑːrdiˈɑː-/ noun [uncountable] the medical study of the heartExamples from the Corpuscardiology• The correct person to initiate and oversee coronary rehabilitation is the district cardiologist or physician with an interest in cardiology.• Modern cardiology is a case in point.• When I was first taught cardiology there was little evidence for the efficacy of secondary prevention after myocardial infarction.• He's now in the cardiology unit.