Unstable angina (UA) is a type of angina pectoris that is irregular.It is also classified as a type of acute coronary syndrome.
Angina (say ANN-juh-nuh or ann-JY-nuh) is a symptom of heart disease. Angina happens when there is not enough blood flow to the heart muscle. This is often a result of narrowed blood vessels, usually caused by hardening of the arteries (atherosclerosis). Angina can be dangerous. Angina (an-JI-nuh or AN-juh-nuh) is chest pain or discomfort that occurs if an area of your heart muscle doesn't get enough oxygen-rich blood. Angina may feel like pressure or squeezing in your chest. The pain also can occur in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion. Angina isn't a disease; it's a symptom of an underlying heart problem. Angina usually is a symptom of coronary heart disease (CHD). Angina occurs when there is not enough blood flow to the heart. Angina can be dangerous. So it is important to pay attention to your symptoms, know what is typical for you, learn how to control it, and know when to call for help. Symptoms of angina include chest pain or pressure, or a strange feeling in the chest.  Unstable angina (UA) is a type of angina pectoris that is irregular. It is also classified as a type of acute coronary syndrome. It can be difficult to distinguish unstable angina from non–Q-wave myocardial infarction.  Unstable angina worsens and is not relieved by rest or your usual medications. If the blood flow doesn't improve, heart muscle deprived of oxygen dies — a heart attack. Unstable angina is dangerous and requires emergency treatment. 1 Variant angina, also called Prinzmetal's angina, is caused by a spasm in a coronary artery in which the artery temporarily narrows. 2  This narrowing reduces blood flow to your heart, causing chest pain. 3  Variant angina can occur even when you're at rest, and is often severe. Angina pectoris (or angina for short) is chest pain or discomfort that occurs when the heart muscle is temporarily not getting enough oxygen-rich blood. A bout of angina is not a heart attack, but it means that you're more likely to have a heart attack than someone who doesn't have angina. The most common types of angina are stable angina and unstable angina. Unstable angina is a dangerous condition that requires emergency treatment. It occurs more often in older adults and is a sign that a heart attack could occur soon. Unstable angina or sometimes referred to as acute coronary syndrome causes unexpected chest pain, and usually occurs while resting. Causes of Unstable Angina: Blood clots that block an artery partially or totally are what causes unstable angina. Blood clots may form, partially dissolve, and later form again and angina can occur each time a clot blocks blood flow in an artery. Unstable angina is a condition in which your heart doesn't get enough blood flow and oxygen. It may lead to a heart attack. Angina is a type of chest discomfort caused by poor blood flow through the blood vessels (coronary vessels) of the heart muscle (myocardium).  Stable angina does not typically occur more frequently or worsen over time. Unstable angina is chest pain that happens suddenly and becomes worse over time. It occurs seemingly without cause—you may be at rest or even asleep. An attack of unstable angina may lead to a heart attack. Coronary heart disease caused by a buildup of plaque (fatty deposits) along the walls of your arteries (atherosclerosis) is the principal cause of unstable angina. The plaque causes your arteries to narrow and become rigid. That constricts blood flow to your heart.
http://www.webmd.com/heart-disease/tc/angina-topic-overview https://www.nhlbi.nih.gov/health/health-topics/topics/angina/ http://www.webmd.com/heart-disease/tc/heart-attack-and-unstable-angina-overview https://en.wikipedia.org/wiki/Unstable_angina http://www.mayoclinic.org/diseases-conditions/angina/basics/causes/CON-20031194 http://heart-disease.emedtv.com/unstable-angina/unstable-angina.html http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Unstable-Angina_UCM_437513_Article.jsp http://www.nytimes.com/health/guides/disease/unstable-angina/overview.html http://www.healthline.com/health/unstable-angina
what is unstable angina