Agent Orange exposure

My cardiologist has diagnosied me with Coronary Heart Disease, I was in Vietnam in 1968-1969 and was exposed to spraying of Agent Orange defoliant.  But he said I do not have Ischemic Heart Disease.  The VA has put IHD on the list of diseases caused by exposure to Agent Orange. What is the difference in IHD and CHD?

[CCF HeartMD6]

It's diffiult to say as both are often used interchangeably. However, coronary artery disease indicates that there is narrowing of the coronary vessels from atherosclerosis (an objective findings) while ischemic heart disase is often used more in a clinical context -- and to indicate problems and/or symptoms that arise from having underlying coronary heart disease, such as left ventricular dysfunction, valvuolpathy, angina, or heart failure symptoms.