Page 28 - May 2015 Volume 9, Number 5

You Gotta Have
The heart is a muscular organ located in the chest whose purpose is to pump blood throughout the body. It consists of four chambers – two atria and two ventricles. The right atrium receives blood from the body and pushes it into the right ventricle, which then pumps the blood to the lungs where it is oxygenated. The blood returns to the heart via the left atrium, and then goes into the left ventricle, which is the chamber that pumps blood throughout the rest of the body.
Like all organs, the heart requires oxygen to function and it has its own circulation provided by the coronary arteries. The coronary arteries arise from the aorta (the main artery leading from the heart) just after its junction with the heart. There are two primary coronary arteries, the left and the right. The right coronary artery supplies blood to the right atrium and ventricle as well as a small portion of the left ventricle. The left coronary artery branches into two smaller arteries, the left anterior descending coronary artery (LAD) and the circumflex artery. These arteries supply the left atrium and the bulk of the left ventricle, the heart’s main pump.
As we age, fat deposits on the walls of these arteries (the process begins in the teens) and as the process continues, other substances in the blood, including calcium and proteins, stick to the fat and form what’s called a plaque. These plaques narrow the diameter of the artery, restricting blood flow. Eventually the plaque “cracks” and serves as a nidus for a blood clot to form. These clots can further impede the blood flow causing the heart muscle to become ischemic (deprived of oxygen).
Cardiac ischemia causes chest pain, especially with exertion (angina), shortness of breath, palpitations, nausea, sweating and a feeling of weakness. The chest pain is usually described as a heavy pressure and may radiate into the left shoulder and down the left arm. With rest, angina may subside, but if the degree of ischemia is sufficient, some heart muscle may infarct (die due to lack of oxygen). That’s the classic “heart attack” or myocardial infarction.
While there is certainly a genetic predisposition to developing coronary artery disease (CAD), the
26 • KING AIR MAGAZINE
progression of the condition is lifestyle related. You can minimize the risk of developing CAD by exercising regularly and maintaining your weight at an optimum level. For many years, health authorities advised eating a diet low in fat, but this is now being questioned. In fact, some researchers believe that many people responded to the low fat guidelines by replacing some of the fat in their diets with carbohydrates. That may have led to the increase in obesity and diabetes we’ve seen over the last 30 years. Both diabetes and obesity are risk factors for CAD. Until the role of diet is clearly understood, it’s best for persons to maintain a normal weight and normal blood lipid levels (cholesterol, high and low density lipoproteins and triglycerides).
Clearly coronary artery disease is of concern to the FAA. Myocardial infarction (MI) can result in sudden incapacitation or even death. If a pilot has symptoms of, or has been diagnosed with coronary artery disease, he
by Dr. Jerrold Seckler
Heart
MAY 2015