Heart disease, also called cardiac disease, is actually a term that includes any disorder that affects the heart. This is different from cardiovascular disease, though. Heart disease only has to do with the heart itself, whereas cardiovascular disease deals with disorders of both the heart and blood vessels (arteries and veins). The most common type of heart disease is coronary artery disease, which is a build-up of plaque in the arteries that feed the heart. Other conditions that fall under the umbrella of heart disease include:

• Angina:  Chest pain caused by a lack of oxygen and blood flow to a section of the heart.
• Arrhythmia:  This is the broad term for an irregular heartbeat. It is when the heart beats too fast (Tachycardia), too slow (Bradycardia), or irregularly (Fibrilation).
• Heart Failure:  This is when the heart cannot pump blood efficiently throughout the body. High blood pressure and coronary artery disease can contribute to heart failure since they leave the heart muscle stiff.
• Myocardial Infarction:  This is what is commonly known as a heart attack. It occurs when a portion of the heart muscle is damaged or “dies” from lack of oxygen and blood flow due to a blockage in the arteries that feed the heart. There are several different symptoms.

Sources: http://www.medicalnewstoday.com/articles/237191.php