Angina Pectoris - Prehospital Emergency Care Management

Angina Pectoris

Introduction

Angina pectoris (AP) represents the clinical syndrome occurring when myocardial oxygen demand exceeds supply. The term is derived from Latin; the literal meaning is "the choking of the chest;" angere, meaning "to choke" and pectus, meaning "chest." The first English-written account of recurrent angina pectoris was by English nobleman Edward Hyde, Earl of Clarendon. He described his father as having, with exertion, "a pain in the left arm…so much that the torment made him pale". The first description of angina as a medical disorder came from William Heberden.

Heberden, a prodigious physician, made many noteworthy contributions to medicine during his career. He presented his observations on "dolor pectoris" to the Royal College of Physicians in 1768. Much of his classic description retains its validity today.

Angina pectoris has a wide range of clinical expressions. The symptoms most often associated to angina pectoris are substernal chest pressure or tightening, frequently with radiating pain to the arms, shoulders, or jaw. The symptoms may also be associated with shortness of breath, nausea, or diaphoresis. Symptoms stem from inadequate oxygen delivery to myocardial tissue. No definitive diagnostic tools that capture all patients with angina pectoris exist. This, combined with its varied clinical expression, makes angina pectoris a distinct clinical challenge to the emergency physician. The disease state can manifest itself in a variety of forms:

Stable angina pectoris is classified as a reproducible pattern of anginal symptoms that occur during states of increased exertion.

Unstable angina pectoris (UA) manifests either as an increasing frequency of symptoms or as symptoms occurring at rest.

Prinzmetal angina or variant angina occurs as a result of transient coronary artery spasms.

These spasms can occur either at rest or with exertion. Unlike stable or unstable angina, no pathological plaque or deposition is present within the coronary arteries that elicits the presentation. On angiography, the coronary arteries are normal in appearance with spasm on angiography.

Cardiac syndrome X occurs when a patient has all of the symptoms of angina pectoris without coronary artery disease or spasm.

Frequency

An estimated 6,500,000 people in the United States experience angina pectoris.

Each year, 400,000 new cases of angina pectoris develop.

Conservative 2006 data show 733,000 acute coronary syndrome (ACS) discharges from hospitals.

Mortality/Morbidity

In 2005, 1 in 5 deaths is from coronary heart disease (both angina and myocardial infarction).

Coronary heart disease is the single greatest killer of American men and women.

The estimated direct and indirect cost for Americans with coronary heart disease in 2006 was $142.5 billion.

Race

The Centers for Disease Control and Prevention (CDC) note that the prevalence of angina and/or coronary heart disease is highest and increasing in Hispanics followed by whites and black non-Hispanics (5%, 4.2%, 3.7%, respectively). This information includes the 50 US states, the District of Columbia, Puerto Rico, and the US Virgin Islands.

Sex

Among Americans aged 40-74 years, the age-adjusted prevalence of angina pectoris (AP) was higher among women than men. Although 2005 CDC data suggest that men (5.5%) have a higher prevalence of angina and/or coronary heart disease than women (3.4%).

Age

The incidence of new and recurrent angina increases with age but then declines at around 85 years.

Statistics from American Heart Association (2008 Data) and Centers for Disease Control and Prevention.

Prehospital Emergency Care Management

Often, patients with angina pectoris rest or lie down to alleviate the pain. If the patient is not naive to cardiac disease, he or she may have access to nitroglycerin. Often, the patient uses nitroglycerin at home to palliate his or her symptoms. A patient who has known stable angina often is able to report what exacerbates the condition and what (as well as how often) is a "normal" number of tablets for him or her to use prior to alleviation of anginal symptoms. Patients are often instructed by their physicians that the use of more than 3 tablets of nitroglycerin necessitates a higher level of care (eg, calling for an ambulance). Some patients are instructed to take aspirin as well. A knowledgeable patient who reports a change in the pattern or presentation of his or her symptoms should be suspected as having worsening or unstable angina. However, any patient who presents to the ED with symptoms of angina should be assessed promptly for signs of acute myocardial infarction (AMI).
Most prehospital care for angina pectoris consists of administering nitroglycerin, oxygen, and aspirin. The ability to obtain a prehospital ECG is becoming more prevalent.