Angina Pectoris and Myocardial Infarction

The most common cause of death in the United States is coronary atherosclerosis ( ath ér-ō-skler-ō ́sis; athere = gruel, sclerosis = hardness), or coronary heart disease (see Clinical View, “Atherosclerosis,” in chapter 23).
This condition is characterized by narrowing of the coronary arteries that reduces blood flow to the myocardium and gives rise to chest pain.
Coronary atherosclerosis can lead to either angina pectoris or myocardial infarction.


Angina pectoris (an ́jı¯-nā , an-ji ́na) is not a disease, it is actually a symptom of coronary artery disease caused by narrowing or blockage of coronary arteries. Generally it results from strenuous activity, when workload demands on the heart exceed the ability of the narrowed coronary vessels to supply blood. The pain from angina is typically referred along the sympathetic pathways (T1–T5 spinal cord segments), so an individual may experience pain in the chest region or down the left arm, where the T1
dermatome is located. The pain diminishes shortly after the person stops the exertion, and normal blood flow to the heart is restored. Although many people are successfully treated for years with medications that cause temporary vascular dilation, such as nitroglycerine, the prognosis and longterm therapy for angina depend on the severity of the vascular narrowing.

Myocardial infarction (in-fark ́shūn) (MI), commonly called a heart attack, is a potentially fatal condition resulting from sudden and complete occlusion (blockage) of a coronary artery. A region of the myocardium is deprived of oxygen, and some of this tissue may die (necrose). The symptoms of MI are often different for men and women. Most men experiencing an MI report a sudden, excruciating, and crushing substernal chest pain, and marked sweating, Many women, however, have relatively little chest pain. When they experience pain, they describe it as an “aching,” “tightness,” or “pressure,” rather than pain, and the main locations are in the back and high chest. In addition, women more often experience shortness of breath, but because they do not exhibit t he traditional or classic symptoms that some doctors expect, it is likely for a female to be sent home from the ER with an incorrect diagnosis of heartburn or anxiety, rather than MI.

source : human anatomy