Generality
Myocardial ischemia is the state of suffering of the resulting heart, thanks to an occlusion of the coronaries, from the reduced supply of oxygenated blood to a more or less extended area of myocardium.
By depriving the heart of the oxygen needed to stay healthy, myocardial ischemia is accompanied by a worsening of pumping activity of the same heart; this leads to various symptoms, including: pain and a sense of pressure in the chest, pain in the left shoulder and arm, pain in the neck and / or jaw, dyspnoea, profuse sweating, dizziness, tiredness at the least effort, nausea and vomiting.
Especially related to atherosclerosis, myocardial ischemia requires a thorough diagnosis, because only in this way is it possible to identify the precise site of the coronary occlusion and plan the most appropriate therapy.
Brief review of the term ischemia
In medicine, the term " ischemia " means any reduction in the flow of blood in a certain tissue or organ, such as to cause a decrease in the supply of oxygen and nutrients.
Oxygen and nutrients in the blood are essential for the survival of tissues and organs in the human body. As a result, a tissue or organ victim of ischemia enters a state of critical distress, which can cause death by necrosis of its constituent cells.
What is myocardial ischemia?
Myocardial ischemia, or myocardial ischemia, is the reduction of the supply of oxygenated blood to an area of the myocardium (ie the heart muscle), followed by a suffering of the latter and, inevitably, by a suffering of the cardiac organ as a whole.
A heart suffering from an episode of myocardial ischemia not only risks necrosis of its muscular component, but also becomes less efficient in its vital action of pumping blood towards the tissues and organs of the human body.
Myocardial ischemia is, therefore, a disorder of the heart, which has consequences, sometimes very serious, on the whole organism.
Causes
Coronary arteries (or, more simply, coronary arteries) supply the heart with oxygenated blood.
Myocardial ischemia occurs due to the presence of an occlusion / obstruction of the coronary arteries, a condition which in medicine is called coronary artery disease or, in more jargon, obstructed coronary arteries .
Causes of coronary heart disease
Coronary artery disease recognizes atherosclerosis and its effects at the vascular level ( thrombo-embolism ) and, as less common causes, coronary vasculitis and coronary spasm episodes.
If the cause of myocardial ischemia is coronary artery disease, then the causative factors of the latter are, indirectly, also the causative factors of the myocardial ischemia itself.
ATEROSCLEROSIS AND MIOCARDIC ISCHEMIA
Atherosclerosis is the process of hardening and thickening of the medium and large caliber arteries, which over time creates the formation of atheromas on the wall of the arterial vessels just mentioned.
Also known as atherosclerotic plaque, an atheroma is an aggregate of lipid material (especially cholesterol ), protein and fibrous, which, in addition to narrowing the vessel lumen during formation, can also suffer injury and / or fragmentation.
From any injuries there is a coagulation process which, by drawing in platelets in place, has the involuntary effect of expanding the atheroma itself ( thrombosis ), thus worsening the extent of the vasal narrowing; from the event of fragmentation, on the other hand, the formation of one or more emboli derives, that is, mobile bodies which, circulating freely in the blood, can lead to the complete occlusion of a blood vessel of equal size, even at a considerable distance from the place of origin.
On the basis of what has just been stated, when they are related to atherosclerosis, the phenomena of coronary heart disease and myocardial ischemia may depend on an atheroma inside the coronary arteries - an atheroma which, following a lesion, has recalled platelets, has become larger further and determined occlusion - or from a fragment circulating in the blood of an atheroma located in a different vessel from the coronary arteries.
Causes and risk factors of atherosclerosis:
- Hypertension
- Hypercholesterolemia
- High triglycerides
- Old age
- Cigarette smoking and smoking
- Diabetes mellitus
- Obesity
- Inflammatory diseases such as systemic lupus erythematosus
CORONARY VASCULITE
In medicine, the word "vasculitis" indicates inflammation of the vascular walls; consequently, with coronary vasculitis, doctors understand the inflammation of the coronary artery walls.
Currently, the precise cause of coronary vasculitis episodes is unclear; it is a fact, however, that there is a correlation between the inflammation of the vascular wall and:
- Infections (eg: hepatitis B and hepatitis C);
- Autoimmune diseases (eg: rheumatoid arthritis, juvenile dermatomyositis and scleroderma);
- Allergic reactions to chemical solvents (eg: pesticides) or drugs (eg NSAIDs, sulfonamides and quinolones);
- Tumors to blood cells (eg, leukemia).
SPASMOVASCULAR CHARGE OF THE CORONARIES
Coronary spasm is the sudden narrowing of a coronary artery due to the sudden and sudden contraction of the muscular component of a portion of the vessel wall.
Coronary spasms can be triggered / promoted by various factors, including:
- Intake of drugs such as cocaine, amphetamines and methamphetamine;
- Excessive exposure to cold;
- Strong emotional stresses;
- Tobacco smoke.
Risk factors
These are risk factors for myocardial ischemia:
- The causes / factors favoring atherosclerosis (eg hypertension, advanced age, cigarette smoking, diabetes mellitus, obesity, etc.);
- The conditions associated with episodes of coronary vasculitis (hepatitis B, rheumatoid arthritis, etc.);
- Factors known to induce coronary spasm (eg: drug intake, excessive exposure to cold etc.).
Types of Myocardial Ischemia
Myocardial ischemia can have a transitory nature - which implies its spontaneous resolution after a certain period of time, with the consequent restoration of the normal blood supply to the myocardium - or permanent character - which implies the impossibility of its spontaneous resolution, the persistence of occlusion at the coronary level and, finally, the death of the heart muscle.
The first type of myocardial ischemia ( transient myocardial ischemia ) is an example of angina pectoris, while the second type of myocardial ischemia ( permanent myocardial ischemia ) is an example of myocardial infarction (or heart attack ).
As it is easy to understand, among the forms of myocardial ischemia just mentioned, the most serious and the most dangerous consequences is myocardial infarction.
Symptoms and Complications
The most representative symptom of myocardial ischemia is chest pain, combined with a sense of pressure on the same anatomical area.
Therefore, various other manifestations may be added to chest pain, including:
- Shoulder pain and / or left arm;
- Back, neck and / or jaw pain;
- Dyspnea, ie shortness of breath or wheezing;
- Tachycardia, ie increase in respiratory rate;
- Profuse sweating;
- Dizziness;
- Limitation of physical abilities, with a sense of tiredness that emerges even after the slightest effort;
- Nausea and vomit;
- Sense of anxiety.
It is important to point out that, in a small number of patients, myocardial ischemia is asymptomatic, ie it does not cause any symptoms or particular sign.
The absence of symptoms from a myocardial ischemia is a very dangerous occurrence, because it prevents the patient from realizing that he is ill and needs appropriate care.
Why is myocardial ischemia causing symptoms?
The symptoms of myocardial ischemia are the manifestation of the greater fatigue that the myocardium finds in pumping blood in the circulation, after receiving a quantity of oxygenated blood inferior to the needs.
Complications
The phenomenon of myocardial ischemia leads to complications, when the occlusion of the coronary arteries is permanent and the myocardium, due to a prolonged lack of oxygenated blood, undergoes necrosis, that is, the death of its constituent cells.
The death of the myocardium is an irreversible event and seriously compromises the functions of the heart, so as to be fatal for the patient in a fair number of cases.
Specifically, serious cardiac arrhythmias (eg, left ventricular fibrillation ) and heart failure are among the complications attributable to the presence of permanent myocardial ischemia.
Remember : death of the myocardium due to permanent myocardial ischemia coincides with myocardial infarction.
Therefore, apart from permanence, the death of the muscular tissue of the heart distinguishes the heart attack from angina pectoris.
When should I go to the doctor?
Especially in a subject at risk of myocardial ischemia (so if the subject smokes, is obese, leads a sedentary lifestyle, has an unbalanced diet, etc.), it is always a valid reason to contact a doctor, or go to the nearest hospital, the apparently unjustified appearance of a pain in the chest, associated with problems such as dyspnea, nausea, profuse sweating, vomiting, sense of anxiety, pain in the left shoulder and / or arm, dizziness etc.
Diagnosis
In light of the dangerous nature of the myocardial ischemia phenomenon, the diagnosis of the latter must be made very quickly, otherwise the patient could develop serious if not fatal complications.
In general, in the list of investigations useful for identifying myocardial ischemia, the following are included: the patient's account of the symptoms, the physical examination, the anamnesis, the echocardiogram, the electrocardiogram, the exercise test, blood tests, coronary angioTAC and coronary angiography .
Tale of symptoms, physical examination and medical history
- The patient's account of symptoms provides very useful information for diagnostic purposes; unfortunately, however, in the most serious situations, ie those in which the patient is unable to express himself due to a strong state of suffering, it is not a viable road;
- The physical examination and the anamnesis serve to further clarify the symptomatological picture and to identify the possible causal factors of the condition in progress.
Echocardiogram
The echocardiogram is the ultrasound of the heart; it has various functions, including showing myocardial alterations due to myocardial ischemia and coronary occlusion which caused the aforementioned ischemic phenomenon.
Electrocardiogram
The electrocardiogram evaluates the heart rate, ie the rhythm at which the heart beats.
An abnormality in the heart rate could be the signal of the reduced blood supply to the myocardium that can be observed at the occurrence of myocardial ischemia.
Stress test
The exercise test is an assessment, in a controlled environment, of the effects of physical activity on the patient and the heart of the latter.
If physical activity is associated with easy wheezing and fatigue, the heart will most likely not fulfill its functions properly.
Blood analysis
Blood tests are used to quantify substances, such as creatine kinase or troponin (cardiac biomarker), whose levels tend to increase with the occurrence of myocardial necrosis.
Coronary angioTAC
The coronary angioTAC is a radiological examination that allows the study of blood circulation in the coronaries.
In a context of myocardial ischemia, it provides information on the degree of coronary occlusion.
coronary angiography
Coronary angiography is a radiological examination that allows specific analysis of blood flow within the coronary arteries and pinpoints the location and severity of any occlusion.
In a context of myocardial ischemia, coronary angiography is the quintessential diagnostic confirmation test.
Therapy
As a rule, the treatment of myocardial ischemia is based on an adjustment (obviously for the better) of the lifestyle and, depending on whether the coronary occlusion is mild or severe, on a drug therapy or on a surgical treatment .
The objectives of this treatment are, substantially, 4 and, in particular, consist of:
- Eliminate the coronary occlusion responsible for the condition in question, so as to restore normal blood flow to the myocardium;
- Prevent complications related to a reduction in myocardial oxygen supply;
- Combating all conditions that favor atherosclerosis and secondary causes of myocardial ischemia;
- Relieve symptoms.
To remember : in the presence of myocardial ischemia, lifestyle adjustment is as important as drug therapy and surgical treatment.
Lifestyle changes
The lifestyle indicated to those suffering from myocardial ischemia includes: the adoption of a healthy and balanced diet, the abolition of smoking and any type of narcotic drug, a limited consumption of alcohol (elimination would be the best choice), the achievement and maintenance of a normal-weight state, the control of blood pressure and cholesterol and, finally, the regular practice of a correct and measured physical activity.
Pharmacological therapy
The drugs used in the presence of myocardial ischemia include:
- Anticoagulants (eg: heparin) and antiplatelet agents (eg: aspirin). They are beneficial because they improve the symptoms, reduce the size of any atheromas present, dissolve any abnormal blood clots and prevent the formation of new atheromas.
- Nitroglycerin . It is a drug with dilator effects against coronary arteries, but it is effective only in the middle of an episode of angina pectoris or myocardial infarction.
- Beta-blockers, ACE inhibitors and angiotensin II receptor antagonists . They are useful in the presence of myocardial ischemia associated with hypertension, as their intake induces a reduction in blood pressure.
- Statins . They are beneficial in the presence of myocardial ischemia related to hypercholesterolemia, as their intake produces a reduction in cholesterol levels.
Surgical therapy
Angioplasty with coronary stenting and coronary bypass operation are among the surgical treatments suitable for countering the phenomenon of myocardial ischemia.
Did you know that ...
In some particular cases of myocardial ischemia, doctors believe it is essential to use both drugs and surgery.
ANGIOPLASTIC WITH CORONARY STENTING
Angioplasty is the medical procedure that allows you to eliminate or, at least, reduce the narrowing or narrowing of a blood vessel, by using a particular catheter.
Stenting, on the other hand, consists of placing a metal prosthesis ( stent ) inside a blood vessel - previously occluded and reopened by angioplasty - in order to keep it patent over time and avoid second occlusions.
As it can be guessed, in a context of myocardial ischemia, angioplasty with stenting has as its object the coronary artery or the coronary victims of occlusion.
BYPASS CORONARICO
Coronary bypass surgery consists of creating a pathway for the passage of alternative blood to the occluded one, by inserting a new coronary vessel.
In other words, during a coronary bypass operation, the operating physician inserts a new coronary artery, the purpose of which is to replace, in functions, the obstructed original coronary artery.
Coronary bypass is a somewhat delicate surgical procedure reserved for the most serious cases of myocardial ischemia.
Prevention
The cornerstones of the prevention of myocardial ischemia are: eating in a healthy and balanced way, practicing regular physical activity, not smoking, not taking drugs, maintaining blood pressure, blood cholesterol and blood triglycerides, and finally, controlling weight body in order to avoid overweight or obesity.
Prognosis
Myocardial ischemia is the signal of a sick heart, which, as reiterated in more than one circumstance, can lead to death.
Two factors affect mainly the prognosis of myocardial ischemia:
- The degree of severity of coronary occlusion. If the problem of obstructed coronaries is severe, the likelihood of myocardial ischemia having a fatal outcome for the patient increases significantly.
- The timeliness of care. Timely use of the most appropriate therapy reduces the likelihood that myocardial ischemia can lead to complications.
