Angina pectoris is a medical condition in which there is chest pain or discomfort that occurs due to a disease or pathology of the coronary arteries (arteries supplying the heart’s muscle, called coronaries because they resemble a “crown” over the heart). It is a mismatch problem between the heart’s demands and supply of oxygen. Stable angina is the most common type of angina.
Causes of angina pectoris
Stable angina is a gradual process featuring the narrowing of the coronary arteries through the deposition of fatty plaques in the walls of the arteries, better known as atherosclerosis. It takes years to show its effects and rarely occurs before the 40s -although the rising trends of sedentary lifestyles and unhealthy diets have reduced that age considerably-. Such narrowing of the coronaries causes a decrease in the flow of blood that reaches the heart’s muscle and, since the heart is sensitive to drops of oxygen supply, impairs its function.
The causes of such fat deposition are various and are better termed “risk factors”; they include the following:
- Tobacco smoking has a detrimental effect on the health of your heart and blood vessels in general. It also “injures” the blood vessels and eases the process of fat deposition. Smoking also causes hypertension.
- Males are more liable to develop coronary artery disease than females and develop this condition at an earlier age owing to the effect of their sex hormones (testosterone), and how they increase the level of bad cholesterol (LDL). On the other hand, females have estrogen, which helps them increase the level of good cholesterol (HDL), thereby keeping the health of their blood vessels roughly until menopause.
- An unhealthy diet especially that rich in refined sugars and saturated fats. Most of the cholesterol in our body is made in the liver from non-fat sources, most importantly, carbohydrates.
- A sedentary lifestyle and lack of physical exercise, because exercise helps burn calories and increase the blood supply to the heart in the long term. It also guards against hypertension.
- Hypertension accelerates the condition as it injures the blood vessels.
- Diabetes is also a significant contributing factor. In diabetes, the body can’t use glucose appropriately due to insulin deficiency and/or resistance. Therefore it uses fats which increases the level of mobilised cholesterol in the body.
- Obesity causes elevated levels of blood cholesterol and increases insulin resistance, predisposing to type 2 diabetes and related cardiovascular problems.
Angina pectoris symptoms
Some of the symptoms in angina pectoris are quite characteristic, while the rest may be vague. The most prominent symptoms are:
Chest pain is the most critical symptom of angina, and although it is termed “pain”, the sensation is usually more like fullness, discomfort, squeezing or pressure sensation in the chest, usually just behind the breastbone. It may also be felt in the jaw, left shoulder, left arm or in the upper abdomen. It may feel like a burning sensation and is commonly confused with indigestion and heartburn. Anginal pain is characteristically aggravated by effort, emotional upset, anxiety, cold weather and heavy meals, and is relieved by rest and sublingual application of nitrates. Anginal pain is usually brief and lasts from 1 to 10 minutes. Due to the chronic nature of the disease, patients are generally able to predict their attacks according to the effort they exerted. This, however, doesn’t mean that the condition is stationary. Instead, it is slowly progressive and will invariably end in angina at rest if not controlled.
Nausea, vomiting and burning sensation of the stomach
When a part of the heart is not well perfused with blood, it is termed “ischemic”. Ischemic areas tend to irritate the nerve close to them -also known as the vagus nerve-, and when they do, it induces a sensation of nausea and perhaps even vomiting. A burning sensation of the area just under your chest (the epigastrium) may also be felt as a result of irritation of the diaphragm over which the heart lies. Such symptoms should never be ignored, and heartburn is often considered sufficient to perform an ECG in the ER.
Breathlessness is a subjective sensation rather than an actual one. The patient reports difficulty breathing, but not all breathlessness is related to actual problems in the lungs or airways. In angina, breathlessness is the product of many complex mechanisms related to defective heart filling with blood secondary to its ischemia. It is exertional just like the pain and relieved by rest. Breathlessness may also be accompanied by rapid breathing and can be a result of the panic attack accompanying angina.
Sweating is our body’s way of decreasing its temperature to avoid overheating which can literally “boil” our brains. It is activated by the autonomic nervous system -yes you guessed it right; it is called auto-nomic because we have no control over it-. In case of angina, it is no different except that there is no excess heat. Angina causes severe distress, leading to the activation of the sympathetic part of the autonomic nervous system, causing the profuse sweating. Any sweating without fever is considered significant enough that it may be the only prevalent symptom of angina.
Fatigue and sense of weakness
It is a less prevalent symptom and vaguer than the previous one. The patient usually complains of a general sense of weakness and inability to perform usual daily tasks.
Angina in females
Although angina affects both sexes and has an overall higher prevalence in males, females with angina develop a set of symptoms that are different from the classical picture mentioned above. This is due to the difference in the way the disease occurs between males and females. The type of angina that affects females is related to the microcirculation rather than the large blood vessels. It may feature a rather sharp pain instead of the usual squeezing or pressure sensation. Women may also complain of an unusual feeling of weakness, fatigue, loss of concentration, or even depression.
Treatment of angina pectoris
Treatment of angina is a multi-modality therapy, which means that a combination of lifestyle and diet modifications with drugs and even interventions may be needed simultaneously to achieve an optimal quality of life.
Management of risk factors is essential and includes:
- Control of hypertension and diabetes through medications dramatically reduces the progression of angina.
- Smoking cessation is a must for all angina patients, as the relationship between coronary artery disease and smoking is direct enough to necessitate absolute smoking cessation.
- Weight reduction is also very important. Maintaining a BMI (Body Mass Index) below the threshold of obesity (30) has a terrific effect on the outcome of angina.
- Maintaining a healthy lifestyle with regular exercise and a healthy diet. Exercises like running, swimming, or even walking tend to improve the heart’s health, prevent and help control hypertension, and even reverse atherosclerosis.
Controlling the risk factors may be sufficient in mild conditions with minimal symptoms and limitations of daily activities, but when the condition progresses and reduces the quality of life of the patient, medications and interventions become necessary.
Vasodilation is increasing the calibre of blood vessels, thus increasing blood flow and oxygen delivery to a specific organ. In angina, they act mainly on the coronaries to help supply the heart with more blood, decreasing the discomfort. The most commonly used family of drugs for this purpose are called Nitrates, and they are either taken in the form of tablets orally for long term effect or sublingually for quick relief of the angina attack. The sublingual route is so rapid that the patient observes and improvement of his condition within a few minutes. They are usually safe unless the patient has a liability to develop hypotension. Never self-medicate with nitrates, as they can interact with many drugs controlling blood pressure and those used for erectile dysfunction like Viagra.
They are a class of drugs that work by inhibiting the effect of the hormone epinephrine, leading to a slowing of heartbeats and decreasing the oxygen needs of the heart. They also lower blood pressure and help relax the muscles of the coronary arteries leading to an improved blood flow.
Aspirin is an anti-platelet drug, meaning that it prevents the aggregation of platelets, thereby decreasing the risk of blood clots in the narrowed arteries. Other antiplatelet drugs may be used, as in Clopidogrel, which works by a different mechanism than aspirin, but eventually achieves the same effect.
Statins are a group of drugs that work by inhibiting the formation of cholesterol in your liver, reducing the level of circulating cholesterol in the blood, and therefore slowing and reversing atherosclerosis.
Calcium channel blockers
Muscles need calcium to contract, and when the calcium is antagonized, it helps relax those muscles. In the case of angina, we use calcium channel blockers to help relax the blood vessels, relaxing the heart, and leading to improved blood flow to the heart muscle.
It is a relatively novel drug that acts by reducing the tension of the heart muscle, and therefore decreasing its oxygen demand. It may be used alone or in combination with other drugs, such as nitrates, beta-blockers and calcium channel blockers.
Although medical therapy with lifestyle modifications are usually sufficient in most cases, interventions, whether surgical or less invasive approaches, may be necessary in advanced cases.
Options for management in such cases include:
Percutaneous Coronary Intervention (PCI)
It is sometimes called angioplasty, and it involves inserting a catheter, which is a tube-like structure into your blood vessels. The usual choices are either vessels of the thigh (the femoral artery or vein) or those of the forearm (the radial artery). Afterwards, the catheter goes with or against the bloodstream until reaching the heart’s blood vessels (the coronaries), the doctor then inflates a balloon at the tip of the catheter to widen the narrowed part of the blood vessel. This is usually followed by the insertion of a stent (a metal or biologic mesh-like structure that keeps the blood vessels distended). The percutaneous coronary intervention has become the mainstay invasive technique in Cardiology and has largely replaced open-heart surgeries in many cases. It has much fewer complications and patients regain their normal lifestyle faster than open-heart surgeries.
Coronary Artery Bypass Surgery
Coronary artery bypass surgery or CABG is an open-heart surgery that is indicated in some cases of angina, as in narrowing of more than one main coronary artery or reduction of the lumen in the left coronary. As the name implies, it involves “bypassing” the narrow arteries by creating a new route for the blood instead of the narrow segment. This new route is a graft or a “piece of an artery or vein” taken from the calves (saphenous vein), forearms (radial artery) or chest (internal mammary artery) of patients. Artery grafts tend to be better than venous in terms of longevity, while veins are the most commonly used as they are easier to get and provide enough length for more than one graft. CABG surgery has the same complications of all open-heart surgeries, and therefore its use is steadily decreasing.