Angina ,definition

Introduction

Angina, or chest pain, is the most common symptom of ischemic heart disease, a major cause of morbidity and mortality worldwide. Chest pain can be due to non-cardiac and cardiac causes, and thorough history and physical is critical in differentiating these causes and identifying patients experiencing acute coronary syndrome. Angina is one of the signs of acute coronary syndrome (ACS) and can further subdivide into stable and unstable angina. Stable angina defines as the occurrence of symptoms with exertion only. Unstable angina or symptoms occurring at rest requires more prompt evaluation and management. Approximately 9 million patients in the United States have symptoms of angina, and recognizing these symptoms is imperative in improving patient outcomes.

Definition: 

Angina is the medical term for chest pain or discomfort caused by a temporary disruption in the flow of blood and oxygen to the heart. People describe angina discomfort as a squeezing, suffocating or burning feeling – usually in the center of the chest, behind the breastbone

Pathophysiology: 

Angina pectoris occurs when :

• Cardiac workload and resultant myocardial oxygen demand exceed the ability of coronary arteries to supply an adequate amount of oxygenated blood. 

• Such imbalance between supply and demand can occur when the arteries are narrowed. Narrowing usually results from coronary artery atherosclerosis but may result from coronary artery spasm or, rarely, coronary artery embolism.  

• Acute coronary thrombosis can cause angina if obstruction is partial or transient, but it usually causes acute myocardial infarction (MI). 

• Because myocardial oxygen demand is determined mainly by heart rate, systolic wall tension, and contractility, narrowing of a coronary artery typically results in angina that occurs during exertion and is relieved by rest. 

• In addition to exertion, cardiac workload can be increased by disorders such as hypertension, aortic stenosis, aortic regurgitation, or hypertrophic cardiomyopathy. In such cases, angina can result whether atherosclerosis is present or not. These disorders can also decrease relative myocardial perfusion because myocardial mass is increased (causing decreased diastolic flow). 

• A decreased oxygen supply, as in severe anemia or hypoxia, can precipitate or aggravate angina. 

Risk factors for angina :

Over time, the coronary arteries are narrowed by a layering of fatty deposits (plaques) in the inner linings of the artery walls "atherosclerosis". These plaques are caused by a combination of factors, including: 

• Unhealthy heavy eating meals 

• Overweight or obesity 

• Insufficient physical activity 

• Smoking 

• High cholesterol levels 

• High blood pressure 

• Unmanaged diabetes 

• With increasing age 

• Genetic factors or having a family history of cardiovascular disease 

• Being a post-menopausal woman 

• Severe mental illness. 

• Exposure to cold 

Signs & symptoms :

• Angina may be a vague, barely troublesome ache or may rapidly become a severe, intense precordial crushing sensation. 
• It is rarely described as "pain." Discomfort is most commonly felt beneath the sternum, although location varies.  
• Discomfort may radiate to the left shoulder and down the inside of the left arm, even to the fingers; straight through to the back; into the throat, jaws, and teeth; and, occasionally, down the inside of the right arm.  
• It may also be felt in the upper abdomen. The discomfort of angina is never above the ears or below the umbilicus

 Types of angina:

 : Stable Angina *

In stable angina, episodes of chest discomfort are usually predictable. They can occur during exertion (such as running to catch a bus) or during mental or emotional stress. Normally, the chest discomfort is relieved with rest, use of nitroglycerin, or both. If you have recurring episodes of chest discomfort, you should see your doctor for a medical evaluation. 

 

 :Unstable Angina *

In unstable angina, chest pain can occur at any time—often while a person is resting. The discomfort may be more severe and last longer than in typical angina. The most common cause is reduced blood flow to the heart muscle because the coronary arteries are narrowed by fatty buildups. If you experience unstable angina you should call your physician immediately as this may be the rise of a more important medical condition. 

 :Variant Angina Pectoris * 

 

Variant angina pectoris can happen at any time. Unlike typical angina, it nearly always occurs when a person is resting. Other names for it are Prinzmetal angina and angina inversa. Attacks can be very painful and usually happen between midnight and 8AM. Variant angina is caused by spasms in the coronary arteries. There is usually no plaque or blood clot. About two-thirds of people with variant angina have severe coronary blockages in at least one major vessel. The spasm usually occurs very close to the blockage.  Smoking or using cocaine may trigger it. Symptoms are severe but get better with medication. Attacks of variant angina usually occur in cycles that come and go. Treatment may 

break the cycles. Variant angina rarely leads to a heart attack.  

:Angina decubitus  *

  

Is angina that occurs spontaneously during rest. It is usually accompanied by a modestly increased heart rate and a sometimes markedly higher BP, which increase oxygen demand. These increases may be the cause of rest angina or the result of ischemia induced by plaque rupture and thrombus formation.  

If angina is not relieved, unmet myocardial oxygen demand increases further, making MI more likely

:Treatment*

                                  

 :The main goals of angina treatment are to

1/   Relieve acute symptoms         

2/  Prevent or reduce ischemia

3/ Prevent future ischemic events 

4/ Modification of risk factors (smoking, BP, lipids) 

5/ Nitroglycerin and calcium channel blockers for symptom control 

6/ Calcium channel blockers are particularly useful if hypertension or coronary spasm is also               present. Different types of calcium channel blockers have different effects. Dihydropyridines   (eg,   nifedipine,   amlodipine, felodipine) have no chronotropic effects and vary substantially in their             negative inotropic effects              

7/ Antiplatelet drugs (aspirin and sometimes clopidogrel, prasugrel, or ticagrelor) to inhibit platelet             aggregation         

8/ Angiotensin-converting enzyme (ACE) inhibitors and statins