Pharmacotherapy/Treatment Of Angina Pectoris

Angina pectoris is a disease of the heart. It is caused by reduced blood flow to the heart. It is a symptom of coronary artery disease (CAD). It is as a result of myocardial ischemia caused by an imbalance between myocardial blood supply and oxygen demand.

Blood flow to tissues and organs supplying vital ingredients such as oxygen. When the heart gets less of it, it begins to die. It leads to pain in the chest.

It is more common than we think. It affects about 8.5 non black men and 10.6 non black women in 1000 population. It is estimated to affect 11.8 black men and 20.8 black women in the same 1000 population. Both under the age of 45-55 years.

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Under the age of 55-65 years, 11.9 non black men and 11.2 non black women are affected in 1000 of the population. The number is 10.6 for black men and 19.3 for black women in 1000 of the population.

Looking at the last age range on the statistics of 65-75 years have the following; 13.7 non black men and 13.1 non black women and 8.8 black men with 10 black women under 1000 population.

The above shows that angina pectoris affects more women than men but vary between black than non black.

Symptoms Of Angina Pectoris

Angina pectoris
Image: Wikipedia

1. A chest pain or discomfort that come with pressure, burning, squeezing that may radiate to the arms, neck, jaw, shoulder or back

2. Dizziness, fatigue, nausea, shortness of breath, fainting, impending sense of doom and pain in upper abdomen

3. Sweating

Women may have additional symptoms such as abdominal pain, stabbing pain instead of chest pressure and discomfort in the neck, jaw and back. Pain above the mandible and above the epigastrium is rarely angina in nature.

Types Of Angina Pectoris

Stable Angina: this is the most common form of angina pectoris. The pain comes during physical activity and goes away on rest. Examples of activities that trigger stable angina are walking uphill, emotional stress, heavy meals, smoking or in cold environments. It is characterized by pain in the chest region that lasts a very short time or disappears with rest or anti-angina medication.

Unstable Angina: comes with varying severity and duration. It signals a dangerous form of angina or a heart attack. It occurs even at rest. It can occur anytime, last longer (30 minutes) and more severe. Its main characteristics is that it does not disappear with rest or the use of angina medication.

Variant Angina (prinzmentals): is a rare form of angina. It occurs due to spasm of heart arteries that temporarily reduce blood flow. Attacks occur in clusters during emotional stress, smoking, medication that tighten blood vessels, etc. It can happen during rest and is very severe. May be relieved by angina medication.

Angina decubitus occurs at night while the patient is recumbent. It is induced by an increase in myocardial oxygen demand caused by expansion of blood volume with increased venous return during recumbency.

Microvascular angina: no coronary artery blockage but small arteries are not working the way they should. This causes pain that lasts more than 10 minutes.

Cause Of Angina Pectoris

The most common cause of reduced blood flow to the heart is CAD. It is a situation whereby the heart arteries are narrowed by fatty deposits called plaque. It is called atherosclerosis.

When the heart arteries are narrowed a little, it causes stable angina. This is because at rest, the heart needs little oxygen which the narrow arteries can supply. However, in physical exertion the heart requires much more oxygen which the narrow arteries cannot supply. Serious blockage from blood clot or other forms of blockage cause unstable angina.

Risk Factors

1. Tobacco

2. Diabetes

3. High blood pressure

4. High cholesterol or triglycerides

5. Family history

6. Age

7. Inactivity

8. Obesity

9. Stress

Complication

Heart attack

Prevention

1. Eat healthy while avoiding alcohol

2. Exercise

3. Reduce stress

Diagnosis

A positive Levine sign suggests angina. This is a situation whereby the fist is clenched over the sternum when describing the nature of chest pain.

Other tests are electrocardiogram (ECG or EKG), stress test, chest x-ray, coronary angiography (catheterization), cardiac computerised tomography (CCT) and cardiac magnetic resonance imaging (MRI). There is a blood test that is used to determine angina pectoris. It shows the presence of certain enzymes in the body that leak out when the heart is damaged.

Chest radiography is normal in angina pectoris. May show cardiomegaly in normal patients with previous myocardial infarction, ischemic cardiomegaly, pericardial effusion or acute pulmonary edema.

Stress testing is the most widely used test for the evaluation of patients presenting with chest pain. In patients with established stable angina, it can provide prognostic information about the extent of the disease. This can be in conjunction with other tests like myocardial perfusion scintigraphy test. Discontinue test in the presence of chest pain, drop in systolic blood pressure of more than 10 mmHg, severe shortness of breath, fatigue, dizziness or near syncope, ST depression of more than 2 mm, ST elevation of at least 1 mm without diagnostic Q halves or development of ventricular tachyarrhythmias.

Stress test procedure involves running on a treadmill or other exercise while hooked up to an ECG which monitors the changes in the heart electrical activity. Stress test has overall sensitivity of 78 percent and specificity of 86 percent. Myocardial perfusion scintigraphy test boasts sensitivity of 83 percent and specificity of 71 percent.

Stress echocardiography evaluates segmental wall motion during exercise. It detects changes in regional wall motion that occurs during myocardial ischemia. Normal myocardium becomes hyperdynamic during exercise; ischemic segments become hypokinetic or akinetic.

Echocardiogram or with nuclear image: a mildly radioactive dye (not used in pregnant women or those allergic to it) is injected into the heart to take an image of the heart at rest or during exercise using a rotating camera. The camera shows the blood supply through the heart muscles.

Pathophysiology Of Angina Pectoris

Angina results when there is an imbalance between the heart's oxygen demand and supply. This imbalance can result from an increase in demand (e.g., during exercise) without a proportional increase in supply (e.g., due to obstruction or atherosclerosis of the coronary arteries).

However, the pathophysiology of angina in females varies significantly as compared to males. Non-obstructive coronary disease is more common in females.

Pharmacotherapy/Treatment Of Angina Pectoris

Treatment is both lifestyle, medication and medical procedure. Goal of medical intervention is to reduce frequency and severity of symptoms and lower the risk of heart attack.

Lifestyle Modification

Treating other diseases that can cause angina pectoris such as hypertension, diabetes, etc.

Medication

Nitrates: nitrates relax and widen the blood vessel. It is used for both treatment and prevention. Example is sublingual nitroglycerin. The dose depends on the severity and response. Angina Pectoris (Acute Relief) is treated by using 0.3-0.6 mg SL q5min up to 3 times; use at the first sign of angina. Prompt medical attention needed if no relief. Dissolve under tongue or in a buccal pouch; do not rinse mouth or spit for 5 minutes after administration. Angina Pectoris (Prophylaxis)

1 tablet SL 5-10 minutes before activities likely to provoke angina attacks.

Aspirin: aspirin prevents blood clot and enables blood to flow easily. It is given 75 mg daily. Another is clopidogrel given 75 mg daily when aspirin is contraindicated.

Beta blockers reduce heartbeat and relax blood vessels. Example is propranolol 40 mg given daily.

Stations are another set of drugs used in angina. It is used to lower cholesterol. Stations also help reabsorbed cholesterol that has accumulated and plaque in the arteries walls. This further prevents blockage of the arteries. Examples are simvastatin 10-80 mg daily at night.

Calcium Channel Blockers are another set of drugs used in widening blood vessels. An example is amlodipine given 5-10 mg daily.

When the other drugs fail, angiotensin converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) may be added. ACEI includes losartan given 50mg daily and ARB candesartan 8 mg daily.

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Ranolazine is used alone or with other medications to treat chronic angina. Ranolazine is in a class of medications called anti-anginals. The exact way that ranolazine works is not known at this time. It is used alone or with other angina medication. It is given 375 mg two. Times daily.

Medical Procedure

1. Angioplasty and stenting (percutaneous coronary intervention, PCI): this procedure involves inserting a tiny balloon into the arteries. It is then inflated to the right size to widen the artery. A small wire mesh coil (stent) is inserted to keep the artery open and the balloon removed. This is the best medical procedure.

2. Coronary artery bypass surgery: in this procedure, a vein or artery of the same size from another part of the body is cut and used to replace the damaged heart artery.

3. External counterpulsation (ECP): in this method, blood type cuffs are placed around the calves, things and pelvis to increase blood flow to the heart.