Coronary heart disease is caused by plaque buildup in the arteries that supply the heart, reducing blood flow. Risk factors include diabetes, high blood pressure, high cholesterol, smoking, being overweight, and lack of exercise. Common symptoms are chest pain and fatigue. Inflammatory heart diseases like myocarditis, pericarditis, and endocarditis involve inflammation of the heart muscle, surrounding sac, or inner lining from infection. Heart failure occurs when the heart can no longer sufficiently pump blood due to conditions like coronary artery disease or cardiomyopathy, where the heart muscle deteriorates over time.