Heart disease is a generalized term which is used to refer to many different disease entities: cardiomyopathy (muscle disease), arrhythmias/dysrhythmias (irregularities in the rhythm of the heart), congenital (birth) defect, valve dysfunction, rheumatic heart disease, coronary artery disease (build up of plaque on the inner walls of the blood vessels), and infarction (damage to the heart muscle, properly called a heart attack). Another frequently used term in heart disease is heart failure, which simply means the pumping chambers of the heart lose their ability to keep up with the amount of blood flow.
As many as a half million Americans die each year from CAD (coronary artery disease), which makes it the single leading cause of death in the United States today. The majority of CAD is due to the build-up of plaque (atheromas) along the walls of the blood vessels. This plaque is made up of cholesterol (LDL in particular), calcium, triglycerides, and fibrin (one of the body's clotting materials). Over time, the build up of plaque can reduce or eliminate bloodflow through the artery, reducing the oxygen delivered. The plaque can also rupture acutely creating a "snag" where a blood clot forms and blocks the artery. This leads to a heart attack.
As the bloodflow is reduced, and therefore the oxygen, symptoms such as angina (chest, jaw, or arm pain) can occur. This reduced bloodflow is referred to as ischemia. Other symptoms of ischemia can include palpitations, GI symptoms such as a bloated or gassy feeling, or burning sensation as occurs with indigestion or reflux. Some people have no symptoms at all - so the absence of these does not rule out CAD.
If the blood supply is cut off for more than a few minutes, muscle cells suffer permanent injury and die. This is referred to as infarction. It can kill or disable someone, depending on how much heart muscle is damaged.
Once the heart muscle reaches a certain level of damage, it cannot be repaired. So, it is in everyone's best interest to have symptoms evaluated as soon as they appear. Risk factors need to be identified and aggressively managed to prevent future complications.
Diet - a diet that is low in saturated fats will reduce the availability of the building blocks of plaque - LDL and triglycerides.
Hypertension - High blood pressure increases the heart's workload, causing the heart to thicken and become stiffer. It also increases your risk of stroke, heart attack, kidney failure and congestive heart failure. When high blood pressure exists with other risk factors the risk of heart attack increases several times.