Coronary Heart Disease: Diagnosis and Treatment

Diagnosis

• The first step is noting the patient’s history and performing a physical examination.
  
• Blood testing: No blood test can definitively diagnose atherosclerosis. However, studies have shown that high blood levels of cholesterol, fibrinogen, homocysteine, C–reactive protein, and some other molecules in the blood are associated with atherosclerosis and risk for heart disease. Other tests are used to measure the levels of cardiac enzymes in the blood to diagnose a heart attack.
  
• Electrocardiogram (EKG): The pattern of electrical activity on an EKG can be used to diagnose a heart attack.
  
• Stress testing: Stress testing is used to evaluate an individual’s risk for heart attack. Patients exercise on a treadmill under close supervision of a physician. The doctor is able to see how the blood vessels in the heart respond to physical stress. If patients experience chest pain, shortness of breath, or EKG abnormalities while exercising, they may be at high risk for a heart attack and may require immediate preventive treatment.
  
  Patients who cannot exercise on a treadmill can have a pharmacologic stress test, in which medications are administered to speed up the heart, mimicking exercise.
  
• Cardiac catheterization is the most accurate way to assess the arteries of the heart and determine the risk for heart attack. A doctor will insert a small catheter into an artery in the leg and then advance it to the heart, where a dye is injected into the coronary arteries. A picture is taken which will show the locations and severities of atherosclerosis, if present. If a blockage is found, the doctor can use an angioplasty procedure (see Treatment section, below) to widen the artery to improve blood flow to the heart.

Treatment

• Diet and lifestyle changes to modify risk factors are the cornerstone of treatment. Prevention strategies include control of blood pressure, reduction of cholesterol, smoking cessation, dietary changes, and exercise. Unfortunately, many patients are not properly counseled regarding the importance of diet and exercise in the prevention of heart disease.
• Many common medical drugs work by decreasing the workload of the heart, thereby decreasing its oxygen requirements. These include nitrates (e.g., nitroglycerin), beta–blockers (e.g., propranolol, atenolol, and metoprolol), and calcium–channel blockers (e.g., diltiazem, verapamil, nifedipine, and amlodipine).
• Other important cardiac drugs, such as aspirin and clopidogrel, work to “thin” the blood, which decreases the risk of artery blockages.
• Cholesterol–lowering medications include “statins” (e.g., Lipitor), cholestyramine, gemfibrozil, and ezetimibe.
• In high–risk patients, surgical intervention may be necessary. This may include angioplasty, in which a small balloon is inflated within a narrowed artery to widen the area of blood flow and a stent is placed to hold the artery open.