Ischemic Heart Disease: Symptoms, Causes, and Treatments
What is ischemic heart disease?
Ischemic heart disease is the disease caused by atherosclerosis of the coronary arteries, that is, those responsible for providing blood to the heart muscle (myocardium) . Coronary arteriosclerosis is a slow process of collagen formation and accumulation of lipids (fats) and inflammatory cells (lymphocytes) . These three processes cause narrowing (stenosis) of the coronary arteries.
This process begins in the first decades of life, but does not present symptoms until coronary artery stenosis becomes so severe that it causes an imbalance between the oxygen supply to the myocardium and its needs. In this case, myocardial ischemia ( stable angina pectoris ) or a sudden occlusion due to thrombosis of the artery occurs , which causes a lack of oxygenation of the myocardium that gives rise to acute coronary syndrome (unstable angina and acute myocardial infarction) .
Ischemic heart disease is a disease that can be significantly prevented if its cardiovascular risk factors are known and controlled. The main factors that produce it are:
- Advanced age
- It occurs more in men, although the frequency in women equalizes after menopause
- Family history of premature ischemic heart disease
- Increased total cholesterol numbers, especially LDL (bad)
- Decreased HDL (good) cholesterol values
- Arterial hypertension
- Mellitus diabetes
- sedentary lifestyle
- Having previously presented the disease (patients who have already presented angina or heart attack are at higher risk than those who have not)
Patients with multiple risk factors are more likely to have obstructive coronary artery disease, and therefore more likely to have angina or heart attack. In addition, in the so-called metabolic syndrome, that is, the association of obesity, diabetes, increased cholesterol and hypertension, patients are at greater risk. The probability of having cardiovascular (coronary) disease or of dying from the heart can be calculated by different scores (SCORE, Framingham, etc.).
Types of ischemic heart disease
- Acute myocardial infarction.
- Stable angina pectoris.
- Unstable angina pectoris.
acute myocardial infarction
It is a serious disease that occurs as a consequence of the obstruction of a coronary artery by a thrombus. The final consequence is the death (necrosis) of the territory that supplies the blocked artery. Therefore, the severity of the myocardial infarction will depend on the amount of heart muscle that is lost. A heart attack is usually an unexpected event that can occur in healthy people, although it is generally more frequent in those with risk factors and in patients who have already suffered another manifestation of ischemic heart disease.
The heart attack is manifested by chest pain with characteristics similar to angina, but maintained for more than 20 minutes. It may be accompanied by fatigue, cold sweat, dizziness, or distress. It is frequently associated with a feeling of seriousness, both because of the perception of the patient himself, and because of the urgent responses that it usually provokes in the healthcare environment that cares for him. But the absence of this sensation does not exclude its presence. It can occur at rest and does not remit spontaneously.
The necrosis of the territory that is left without blood supply is progressive. The damage increases over time, and once the portion of the heart muscle dies, it is impossible to recover its function. However, the damage can be interrupted if the myocardium receives blood again through procedures that unclog the blocked artery.
Therefore, it is essential that the person who is suffering a heart attack arrives at the hospital as soon as possible. Ideally, you should receive care within the first hour of the onset of symptoms. If this is not possible, during the hours following the heart attack, treatments such as thrombolysis (drugs administered intravenously that dissolve the thrombus) or angioplasty (mechanical recanalization of the blocked artery with catheters) should be applied. Sometimes it may even require urgent cardiac surgery. The sooner the patient is treated, the greater the chances of avoiding permanent damage.
More information in the section on heart attack.
Stable angina pectoris is manifested by recurrent chest pain due to myocardial ischemia. Those who have suffered it define it with terms such as oppression, tightness, burning or swelling. It is located in the sternum area, although it can radiate to the jaw, throat, shoulder, back, and left arm or wrist. It usually lasts between 1 and 15 minutes. Angina pain is triggered by physical exertion or emotions and is relieved in a few minutes with rest or sublingual nitroglycerin. It usually worsens in circumstances such as anemia, uncontrolled hypertension, and fever. In addition, cold weather, smoking, humidity, or a large meal can increase the intensity and frequency of anginal episodes.
It is performed mainly due to clinical suspicion of chest pain, although additional tests are not ruled out if other atypical symptoms are present. Patients with suspected stable angina pectoris also usually have an electrocardiogram done.
The stress test or ergometry It is the most widely used test when there are doubts in the diagnosis of myocardial ischemia and it is also used to obtain prognostic information in patients with angina. The patient performs continuous exercise on a treadmill or cycle ergometer to assess his clinical response (if there is pain during exercise) and his electrical response (if there are changes in the electrocardiogram during exertion that suggest myocardial ischemia). This test cannot be assessed if there are baseline electrocardiogram abnormalities or if the patient is taking certain drugs (for example, digoxin). Obviously, a stress test cannot be performed if the patient has some locomotor problem that prevents him from walking correctly. In these cases, stress tests are done with drugs (dobutamine) or radioisotopes.
Coronary arteriography (coronary angiography or catheterization ) is the reference method for the diagnosis of coronary narrowing and is also useful in the event that it is necessary for their treatment (dilation and stent implantation). Given that it is an invasive and moderately expensive test, it is reserved for whether the results of the previous tests are conclusive of significant coronary disease and with poor prognostic data. It is also used in patients with atypical symptoms when non-invasive tests are inconclusive.
The prognosis is highly variable, as it depends on the extent of the disease and how damaged the heart muscle is. There are patients who are controlled and who barely present symptoms while others have a short life expectancy. The factors that most influence the prognosis are the good or bad control of coronary risk factors.
Patients with angina should monitor cardiovascular risk factors and follow periodic controls to prevent the appearance of new ones. To correct them you must:
- quit tobacco
- Monitor hypertension and diabetes and their treatment (weight, diet, drugs)
- Follow a diet low in cholesterol and fat
- Achieve an ideal body weight
- Reduce cholesterol until an LDL is less than 70 mg/dl
Regarding drug treatment, except in cases of contraindications, all patients with coronary disease should take acetylsalicylic acid (there are many commercial preparations, but the best known is Aspirin®) chronically, daily and at low doses (100–150 mg). ) for its antiplatelet effect.
Patients are also treated with beta-blockers as the main treatment and nitrates (orally, sublingually or in transdermal patches), calcium antagonists, ivabradine and ranolazine are recommended to improve symptoms. Patients with frequent attacks of angina undergo treatment with several combination drugs.
Some patients with angina are candidates for coronary revascularization treatments (consist of correcting these narrowing), which can be performed by heart bypass surgery (bypass) or by coronary angioplasty (with catheterization). The choice between one or the other depends on the characteristics of the disease:
- Coronary angioplasty . It is performed when coronary disease allows this technique. A catheter is advanced up to the coronary artery and balloon dilated. A stent (metal device like a cylindrical mesh) is then implanted inside the artery to achieve patency whenever possible.
- Bypass . For patients with more diffuse coronary disease, when angioplasty is not possible and especially if there is poor left ventricular function. It is performed with opening of the thorax and general anesthesia.
unstable angina pectoris
It is usually a sign of very high risk of acute myocardial infarction or sudden death. Unstable angina is triggered in the same way as heart attack, but in this case there is no complete occlusion of the coronary artery by the thrombus and cardiac cell death has not occurred. It is manifested at rest by pain or tightness that begins in the center of the chest and can spread to the arms, neck, jaw, and back. That is, the symptoms are the same as those of a heart attack, although generally of less duration and intensity. This angina must be treated as an emergency, since there is a high risk of a heart attack, a serious arrhythmia or sudden death.