Thursday, February 11, 2010
Whether the name on the chart is Bill Clinton or John Q. public, the approach to chest pain in the ER is roughly the same, give or take the presence of a few secret service agents. There are many causes of chest pain but in a patient like Mr. Clinton, who has had previous bypass surgery, heart attack is always a major concern.
The worry is that a heart attack or myocardial infarction might be in progress. When one of the coronary arteries or blood vessels that supplies the heart muscle with oxygen becomes blocked, muscle begins to die. Time is muscle and the rush begins with the triage nurse or even beforehand if an ambulance is called. If the symptoms suggest the potential for heart attack, treatment guidelines suggest that an EKG be completed within 10 minutes of arrival to the hospital. A brief look at the EKG allows the doctor to know that the patient is indeed having a heart attack and the blocked blood vessel needs to be reopened. Two options exist, emergency heart catheterization where a balloon is used to open up the blockage or intravenous clot busting medications like TNK or TPA. (In the US, less than half of hospitals have emergency heart cath capabilities).
If the EKG does not show an acute heart, the diagnostic challenge begins. Angina, the term used to describe pain from heart muscle that isn’t getting enough oxygen, can present in a variety of ways. Patients may adamantly deny pain being present but instead complain of chest tightness or fullness or a squeezing. There may be indigestion and upper abdominal discomfort. The pain or ache may be in the arms or the jaw. There may be no pain or discomfort but the anginal equivalent might be the complaint of shortness of breath. The diagnosis of a potential heart problem begins with listening to the patient, asking probing questions and looking for potential risk factors for heart disease.
Those risk factors include smoking, high blood pressure, high cholesterol, diabetes and family history of heart disease. Other questions might probe recent exercise intolerance or shortness of breath on exertion which might be a clue that symptoms have been developing over time and have been ignored or not recognized by the patient, For Mr. Clinton, his risk factor for heart disease was 100%; he had bypass surgery 6 years ago.
History is also helpful in looking for other potential causes of the chest pain like pulmonary embolus (blood clot to the lung), dissecting aortic aneurysm (damage to the major blood vessel in the chest), pericarditis (inflammation of the sac lining of the heart) and reflux esophagitis (inflammation of the swallowing tube) among numerous others. Physical examination complements the history but the gold is found in talking to the patient.
If the patient continues to have pain at rest and the working diagnosis is that pain is coming from the heart, the goal is to resolve the pain quickly and try to protect the hear t muscle from damage while the diagnosis is confirmed. Aspirin is given to make platelets less sticky and prevent blood clots form occurring in the narrowed coronary artery. Nitroglycerin is given by tablet under the tongue, by paste on the chest or intravenously to dilate the coronary arteries. Heparin is used to thin the blood to again prevent the potential for blood clot formation. It’s a little backwards, treatment is started even before the diagnosis is confirmed but it’s only because heart muscle is so precious, it is better to treat a patient and prove that it’s not a heart problem than to delay treatment for a patient whose heart needs help.
Not every patient who has chest pain needs a heart catheterization to look for blockage. Less invasive ways of checking out the heart can be used but the test needs to be tailored to the patient and their situation. Stress test, echocardiography (heart ultrasound), cardiac CT and MRI are alternatives that may be appropriate to use to assess heart function and blood flow.
Mr. Clinton ended up with a heart catheterization where a small tube is inserted into the femoral artery in the groin or the brachial artery in the elbow and is snaked into the arteries of the heart. Dye is injected, x-rays taken and if a blockage occurs, the same catheter is equipped with a balloon that can be inflated to squash the blockage into the blood vessel wall, reopening it and re-establishing blood supply to the heart muscle. There may be a next step depending upon the situation. Using the same catheter technique, a stent or cage can be inserted to act like a scaffold to keep the blood vessel open and prevent it from reclogging.
The purpose of all this work is to prevent a heart attack from happening. Mr. Clinton listened to his body and sought medical care quickly. While he ended up with a heart cat hand stent, his work isn’t done. He and his doctors will work hard at further decreasing his cardiac risk factors to prevent the next event. He is a young man and at age 63 will want to look forward to years of being able to have a body that allows him to enjoy life, perform public service and participate in family celebrations