Triage^® Cardiac Panel: Chest Pain & Acute Coronary Syndromes

The term “heart attack” is commonly used to describe a variety of life-threatening heart conditions, some of which are not heart attacks at all. In the clinical setting, heart attack and acute myocardial infarction (AMI) are synonymous. AMI is not caused by dysfunction within the heart itself, but by a blockage in one or more of the coronary arteries, which perfuse the heart muscle with oxygen-enriched blood. When a blockage reduces or completely obstructs blood flow to part of the heart muscle, the muscle tissue may be damaged or destroyed. The affected area, called the infarct region, may become incapable of contributing to the pumping action of the heart. The larger the infarct region, the greater the likelihood of disability or death.

Blockages in the coronary arteries are typically the result of coronary artery disease (CAD), also known as ischemic heart disease and coronary atherosclerosis. CAD develops over a period of time, usually years, as fatty deposits collect along the walls of the arteries. The fatty deposits form a mass of plaque, which narrows the inner passageway of the vessel. This narrowing is referred to as stenosis. As the stenosis increases, the patient develops myocardial ischemia, the insufficient supply of oxygen to the heart muscle, or myocardium. The first symptom can be chest pain, shortness of breath, or general feeling of impending doom.

A patient experiencing chest pain is not necessarily having a heart attack. The pain may be angina–chest pain attributable to myocardial ischemia, but not causing immediate damage to the heart muscle. In patients with stable angina, chest pain occurs only upon exertion. Unstable angina occurs without correlation to physical activity, indicating that the supply of oxygenated blood to the heart muscle is insufficient. Since it does not resolve with rest, unstable angina requires more immediate attention and usually hospital admission to prevent it from proceeding to a heart attack or acute myocardial infarction.

It may be particularly difficult to distinguish unstable angina from AMI because the symptoms are identical. It may also be difficult to distinguish one form of AMI from another. The symptoms vary from patient to patient and can even be confused with indigestion. A patient suffering from AMI requires immediate treatment to prevent the loss of viable heart muscle. While a patient suffering from unstable angina also requires immediate treatment, the condition is not considered immediately life threatening.

Other coronary syndromes can bring a patient into the emergency department or physician office with chest pain. These include “structural problems,” such as valvular heart disease, aneurysms, and heart failure, or “electrical conduction problems,” such as arrhythmias or fibrillation problems of the chambers of the heart. A critical objective in diagnosing patients with chest pain is to rapidly stratify patients into different levels of risk to ensure that the appropriate treatment is provided and that healthcare resources are properly utilized.