Angina pectoris is a term for myocardial ischemia (lack of oxygenated blood to heart muscle) resulting in a typical pattern of tightness or heaviness in center of chest that occurs with exertion and decreases with rest.
Unstable angina is any of following:
Increased severity, frequency, or duration of angina attacks.
Angina pectoris at rest or with mild exertion.
Other types of angina:
Prett's angina (rare)
Decubitus angina (lying down)
Epidemiology and statistics
Prevalence of angina pectoris: 6.4 million (Third National Health and Nutrition Survey 1988-1994)
Penetration rate: about 42 people, or 2.35%, or about 1 in 6.4 million people.
The initial diagnosis of unstable angina occurs in one million hospital admissions each year.
The average age is 62.
The proportion of patients older than 65 years is 44%.
The overall rate of death from coronary heart disease is 0.5 per 1000 people.
Early post-hospital mortality is about 4%, and MI is about 10%.
Hypertrophic obstructive cardiomyopathy
Some risk factors increase incidence of disease and its complications.
Age: The incidence rate increases with age and incidence rate at age 50 is 1.5 per 1000. The median age was 62 years and 40% of patients were over 65 years of age.
Gender Men more often than women (especially premenopausal women). Men are five times more likely to develop condition by age of 50.
Serum cholesterol An LDL to HDL ratio greater than 4:1 significantly increases risk. Instead, higher HDL levels appeared to provide protection. Serum cholesterol should be maintained below 200 mg/dl.
Smoking* increases incidence by 60%.
Hypertension: The risk increases during both systole and diastole.
diabetes is known to increase incidence of CHD in both men and women.
Family history Family predispositions are known to exist, in part due to inheritance of above risk factors.
Oral contraceptives are associated with an increased incidence of myocardial infarction.
Gout, personality type A, corneal arches in preterm infants, obesity, hypertriglyceridemia, and diagonal earlobe folds have been reported to increase risk of coronary heart disease.
A patient with typical symptoms (tightness or heaviness in center of chest caused by exercise and relieved at rest). It may radiate to arms, neck, jaw, or teeth. ) + risk factors confirm angina pectoris in 90% of cases.
In patients with atypical symptoms and no risk factors, incidence of angina is <25%.
Associated symptoms include difficulty breathing, nausea, sweating, and fainting.
ECG showing ST segment depression during a seizure or exercise test.
The main problem is to distinguish unstable angina from non-Q wave myocardial infarction. This has been established by detecting elevated enzymes in patients who have had myocardial infarction.
Be aware of risk of myocardial infarction with unstable angina (10–20% without treatment, 5–7% with treatment).
Hospitalization, rest, settling adjustment, and risk factors (eg, lipid-lowering therapy to reduce mortality).
Ischemic therapy: IV nitroglycerin is preferred because drug levels are easy to ascertain. Start at 10mcg per mint and increase to 5mcg per mint to relieve chest pain without affecting circulation. After 24 hours, asymptomatic patients should be switched to a long-acting nitrate preparation. Symptomatic patients may take sublingual nitroglycerin every 1/2 hour. Switch to isosorbide mononitrate for prophylaxis in asymptomatic patients. Be sure to allow 8 hours of nitrate-free time to avoid developing a tolerance. Beta-blockers (atenolol 50-100 mg/day) as this combination reduces risk of myocardial infarction. Second-line calcium channel blockers (diltiazem 90 mg/day or amlodipine 5 mg/day), beta-blockers when contraindicated and only for relief of symptoms of ischemia, because Mi.
Thrombosis suppression: Heparin and aspirin reduce risk of myocardial infarction and subsequent death. Combined drugs are better than single drugs. Heparin was administered at a dose of 80 U/kg followed by an infusion of 18 U/kg/hour. Ampoule of heparin 5000 IU, protamine sulfate antidote 50 mg/10 min IV. Monitor APTT every 6 hours, 1.5-2 times higher than therapeutic level compared to control level. Heparin is usually given within 48 hours or before angiography. Another option is low molecular weight heparin s/c 1 mg/kg s/c without APTT control. Aspirin taken at a dose of 160-325 mg per day can reduce death rate by 34%. Ticlopidine Patients who cannot take this drug. GP IIb/IIIa can start 4 days before PTCA and continue 12 hours later (abciximab). The above three elements (triple antithrombotic therapy) provide most effective treatment for infarction prevention.
Symptoms: Morphine for pain relief (also has a small TD effect).
Special circumstances. Thrombolytics should only be used in patients with persistent ST elevation or new LBBB. Increases risk of myocardial infarction. Intra-aortic balloon pumping should only be used to stabilize patients with PTCA or CABG.
About 80% will receive aggressive treatment.
Asymptomatic individuals after 48 hours of drug treatment should be stratified by exercise testing. (details). Individuals with a markedly positive stress response should be referred to an angiography unit.
Patients with refractory ischemia or elevated baseline enzyme levels are at increased risk of cardiac death and should be referred for coronary angiography and possible revascularization.