"Vascular disease of the heart"
Cardiology as a medical specialty did not yet exist, but there were physicians who recognized the "sounds and symptoms" specific to coronary artery disease.The modern stethoscope was just coming into popular use and physicians did not measure blood pressure - so hypertension was not yet a thing. Physicians treated heart disease based on the symptoms and how the physician had been trained. Although we gained a lot of knowledge about hygiene and communicable disease during the Civil War, there was very little advance in the diagnosis and treatment of heart disease.