Angina & Heart Attack
The worry for patients and healthcare providers is that any chest pain may originate from the heart. Angina is the term given to pain that occurs because blood vessels to the heart muscle narrow and decrease the amount of oxygen that can be delivered to the heart itself. This can cause the classic symptoms of chest pressure or tightness with radiation to the arm or neck associated with shortness of breath and sweating.
Unfortunately, many people don't present with classic symptoms, and the pain may be difficult to describe - or in some people may not even be present. Instead of angina or typical chest pressure, their anginal equivalent (symptom they get instead of chest pain) may be indigestion, shortness of breath, or weakness and malaise. Women and the elderly are at higher risk for having atypical presentation of heart pain.
If one of the blood vessels to the heart (coronary artery) completely occludes (becomes blocked), then the muscle it supplies blood to is at risk of dying. This is a heart attack or myocardial infarction. In most circumstances, this pain is more intense than routine angina, but again, there are many variations in signs and symptoms.
The diagnosis of angina is a clinical one. After the healthcare provider takes a careful history and assesses the potential risk factors, the diagnosis is either reasonably pursued or else it is considered not to be present. If angina is the potential diagnosis, further evaluation may include electrocardiograms (EKG or ECG) and blood tests.
Cardiac enzymes can be measured in the bloodstream when heart muscle is irritated or damaged. If these chemicals are not present, it may be reasonable to perform imaging studies of the heart in a variety of ways depending on the patient's past history:
- Stress tests in which the electrocardiogram is monitored during exercise
- Echocardiography (ultrasound evaluation) of heart structure and function
- Computerized cardiac angiography in which the CT scan can image the heart's blood vessels
- Coronary catheterization, in which tubes are floated through a major blood vessel into the heart and dye is used to directly image heart blood vessels looking for blockage
The purpose of making the diagnosis of angina is restore normal blood supply to heart muscle before a heart attack occurs and permanent muscle damage occurs. Aside from minimizing risk factors by controlling blood pressure, cholesterol, and diabetes, and stopping smoking, medications can be used to make the heart beat more efficiently (for example, beta blockers), to dilate blood vessels (for example, nitroglycerin) and to make blood less likely to clot (aspirin).
An acute heart attack (myocardial infarction) is a true emergency, since complete blockage of blood supply will cause part of the heart muscle to die and be replaced by scar tissue. This lessens the ability of the heart to pump blood to meet the body's needs. As well, injured heart muscle is irritable and can cause electrical disturbances like ventricular fibrillation, a condition in which the heart jiggles like Jello and cannot beat in a coordinated fashion. This is the cause of sudden death in heart attack. The cause of an acute heart attack is the rupture of a cholesterol plaque in a coronary artery. This causes a blood clot to form and occlude the artery.
The treatment for heart attack is emergent restoration of blood supply. Two options include use of a drug like TPA or TNK to dissolve the blood clot (thrombolytic therapy) or emergency heart catheterization and using a balloon to open up the blocked area (angioplasty) and keeping it open with a mesh cage called a stent.