Angina pectoris, commonly called angina, is characterized by chest pain that results from myocardial ischemia.
Stable angina is usually predictable, occurs in situations that increase myocardial oxygen demand such as exercise or stress and is relieved by rest or sublingual nitroglycerin. Unstable angina occurs unexpectedly and usually at rest or lasts longer than stable angina.
Variant angina, also called Prinzmetal’s angina, is a form of unstable angina caused by coronary artery spasm. Unstable angina is considered an emergency and it may be a harbinger of acute myocardial infarction or sudden death.
The most common cause of angina is impaired blood flow secondary to coronary atherosclerosis.
Other causes include coronary artery spasm, or constriction, of very small blood vessels in the coronary circulation, also called Cardiac Syndrome X, and factors that reduce oxygen carrying capacity to blood, such as anemia. Microvascular angina is a diagnosis of dysplasia, which is made when the angina is accompanied by an abnormal exercise test, normal coronary arteries and the absence of inducible coronary artery spasm.
The severity of angina is often graded on a 4-point scale with Functional Class IV being the most severe. This is inability to perform any physical activity without discomfort.
Medications used to treat angina include sublingual nitroglycerin for acute attacks, beta blockers and calcium channel blockers.
Surgery such as coronary artery bypass or angioplasty is recommended in some patients. Comprehensive treatment of angina also includes controlling risk factors such as obesity, hypertension, hyperlipidemia, diabetes and cigarette smoking in order to slow the progression of atherosclerosis and decrease the risk of myocardial infarction.
In healthy volunteers who consumed 5 meals that ranged from 50-75% of a daily end requirements, there was a significant positive correlation between the meal size and myocardial oxygen consumption. This finding suggests that patients who experience postprandial angina could benefit from consuming small frequent meals as opposed to larger less frequent meals.
In a number of cases reported in which attacks of angina were triggered by reactive hypoglycemia, in these cases blood sugar drops too low. In most of these patients, further episodes were prevented by dietary modifications designed to regulate blood glucose levels.
Alcohol consumption has been shown to reduce anginal attacks in a large proportion of patients with variant angina with a lag time of 1.5 to 18 hours and to decrease exercise tolerance in patients with stable exertional angina. Patients with angina should be advised to avoid alcohol or limit its intake not to provoke an attack. Alcohol-induced variant angina may also be aggravated by magnesium deficiency, which is common in heavy alcohol users.
Comprehensive dietary interventions include restriction of fat, elimination of refined sugar, and a consumption of healthy foods such as fruits, vegetables and whole grains and legumes. These studies have resulted in improving the patients. Other lifestyle changes are also recommended.
In addition to preventing spasm of coronary arteries, magnesium plays a role in myocardial energy production by functioning as a cofactor for ATP syntheses. ATP is energy. Several studies have found that magnesium deficiency is common in patients with angina. In some case reports, administration of a series of magnesium injections resulted in complete resolution or marked improvement in some patients with angina. Oral magnesium supplementation was also found in a double-blind trial to be of some benefit to patients with angina.
Plays a role in myocardial energy production by facilitating the transport of fatty acid to the mitochondria. In clinical trials, supplementation with carnitine improved exercise tolerance in patients with stable angina.
As a cofactor in electron transport chain, Q10 plays a role in myocardial energy production. In a double-blind trial, supplementation with Q10 decreased the frequency of anginal episodes and increased exercise tolerance compared with placebo in patients with stable angina. This study was small and was not statistically significant. Large doses of Q10 were not used and Q10 serum levels were not monitored. Further investigation is needed.
As a precursor to nitric oxide, arginine and beets both have a vasodilator effect and have also been shown to improve coronary small vessel endothelial function. There was an improvement of exercise capacity in patients with stable angina and decreased frequency and severity.
Numerous studies have shown supplementation with moderate doses of fish oil, such as 1 to 3 grams, can play an important role in the prevention and treatment of cardiovascular disease and the use of such dose seems reasonable as part of a comprehensive treatment program for patients with angina.
Increased oxidant stress may play a role in the pathogenics of angina and coronary spasm. Antioxidants such as vitamin E might therefore be beneficial for preventing and treating angina and so administered should be in the form of mixed tocopherol as opposed to pure alpha tocopherol in order to prevent alpha tocopherol-induced depletion of gamma tocopherol, which could have deleterious effects on the cardiovascular system.
Angina can result from hypothyroidism and sometimes resolves after treatment with thyroid hormone; however, such treatments may exacerbate preexisting angina or trigger its appearance in patients with coronary heart disease. In addition, treating with thyroid hormone may trigger atrial fibrillation in susceptible individuals, especially the elderly. There are many patients with clinical evidence of hypothyroidism where the laboratory evidence appears normal. There have been reported cases of decreased angina and increased exercise tolerance. In my experience, standard laboratory tests for thyroid function are frequently normal in patients with clinical evidence of hypothyroidism. An empiric trial of thyroid hormone often relieves a wide variety of symptoms.
(see “Congestive Heart Failure” for more a more detailed explanation)
Summary and Recommendations for Angina:
- Eat small, frequent meals.
- Identify and treat hypoglycemia.
- Identify and avoid allergic foods.
- Restrict intake of refined sugar, alcohol and caffeine.
- Consider a vegetation diet.
- Take magnesium, carnitine, Co-enzyme Q10, fish oil, vitamin E, arginine and ribose. The ribose actually will increase cardiac ATP reserve.