The heart is like any other muscle in body. It needs an adequate blood supply to provide oxygen so that the muscle can contract and pump blood to the rest of the body. Not only does the heart pump blood to the rest of the body, it also pumps blood to itself via the coronary arteries. These arteries originate from the base of the aorta (the major blood vessel that carries oxygenated blood from the heart) and then branch out along the surface of the heart.

When one or more coronary arteries narrow, it may make it difficult for adequate blood to reach the heart, especially during exercise. This can cause the heart muscle to ache like any other muscle in the body. Should the arteries continue to narrow, it may take less activity to stress the heart and provoke symptoms. The classic symptoms of chest pain or pressure and shortness of breath due to atherosclerotic heart disease (ASHD) or coronary artery disease (CAD) are called angina.

Should one of the coronary arteries become completely blocked — usually due to a plaque that ruptures and causes a blood clot to form — blood supply to part of the heart may be lost. This causes a piece of heart muscle to die. This is called a heart attack or myocardial infarction (myo=muscle + cardia=heart + infarction= tissue death).

Cardiovascular disease, for this article, will be limited to describing the spectrum of atherosclerosis or hardening of the arteries that ranges from minimal blockage that may produce no symptoms to complete obstruction that presents as a myocardial infarction. Other topics, such as myocarditis, heart valve problems, and congenital heart defects will not be covered.

There are risk factors that increase the potential to develop plaque within coronary arteries and cause them to narrow. Atherosclerosis (athero=fatty plaque + sclerosis=hardening) is the term that describes this condition. Factors that put people at increased risk for heart disease are:

• Smoking
• High blood pressure (hypertension)
• High cholesterol
• Diabetes
• Family history of heart problems, especially heart attacks and strokes
• Obesity

Since cardiovascular disease, peripheral artery disease, and stroke share the same risk factors, a patient who is diagnosed with one of the three has increased risk of having or developing the others.

• The classic symptoms of angina, or pain from the heart, are described as a crushing pain or heaviness in the center of the chest with radiation of the pain to the arm (usually the left) or jaw. There can be associated shortness of breath sweating and nausea.
• The symptoms tend to be brought on by activity and get better with rest.
• Some people may have  indigestion and nausea while others may have upper abdominal, shoulder, or back pain.
• Unstable angina is the term used to describe symptoms that occur at rest, waken the patient from sleep, and do not respond quickly to nitroglycerin or rest.

Not all pain from heart disease have the same signs and symptoms. The more we learn about heart disease, the more we realize that symptoms can be markedly different in different groups of people. Women, people who have diabetes, and the elderly may have different pain perceptions and may complain of overwhelming fatigue and weakness or a change in their ability to perform routine daily activities like walking, climbing steps, or doing household chores. Some patients may have no discomfort at all.

Most often, the symptoms of cardiovascular disease become worse over time, as the narrowing of the affected coronary artery progresses over time and blood flow to that part of the heart decreases. It may take less activity to cause symptoms to occur and it may take longer for those symptoms to get better with rest. This change in exercise tolerance is helpful in making the diagnosis.

Often the first signs and symptoms of heart disease may be a heart attack. This can lead to crushing chest pressure, shortness of breath, sweating, and perhaps sudden cardiac death.

Heart or cardiovascular disease is the leading cause of death in the United States and often can be attributed to the lifestyle factors that increase the risk of atherosclerosis or narrowing of arteries. Smoking, along with poorly controlled hypertension (high blood pressure), and diabetes, causes inflammation and irritation of the inner lining of the coronary arteries. Over time, cholesterol in the bloodstream can collect in the inflamed areas and begin the formation of a plaque. This plaque can grow and as it does, the diameter of the artery narrows. If the artery narrows by 40% to 50%, blood flow is decreased enough to potentially cause the symptoms of angina.

In some circumstances, the plaque can rupture or break open, leading to the formation of a blood clot in the coronary artery. This clot can completely occlude or block the artery. This prevents oxygen-rich blood from being delivered to the heart muscle beyond that blockage and that part of the heart muscle begins to die. This is a myocardial infarction or heart attack. If the situation is not recognized and treated quickly, the affected part of the muscle cannot be revived. It dies and is replaced by scar tissue. Long term, this scar tissue decreases the heart’s ability to pump effectively and efficiently and may lead to ischemic cardiomyopathy (ischemic=decreased blood supply + cardio=heart + myo=muscle + pathy=disease).

Heart muscle that lacks adequate blood supply also becomes irritable and may not conduct electrical impulses normally. This can lead to abnormal electrical heart rhythms including ventricular tachycardia and ventricular fibrillation. These are the heart arrhythmias associated with sudden cardiac death.