Depriving the heart of the oxygen it needs to stay healthy, myocardial ischemia is accompanied by a worsening of the pumping activity of the same heart; this gives rise to various symptoms, including: pain and a sense of pressure in the chest, shoulder pain and in the left arm, pain in the neck and / or jaw, dyspnoea, profuse sweating, dizziness, tiredness at the slightest 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" refers to any reduction in blood flow in a certain tissue or organ, such as to cause a drop in the supply of oxygen and nutrients.
The oxygen and nutrients contained in the blood are essential for the survival of the tissues and organs of the human body. As a result, a tissue or organ that is affected by ischemia enters a state of critical suffering, which can cause death by necrosis of its constituent cells.
A heart suffering from an episode of myocardial ischemia not only risks the necrosis of a muscle 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 heart disorder, which has consequences, sometimes even very serious, on the whole organism.
, a condition that in medicine is called coronary artery disease or, in more slang terms, obstructed coronary arteries.
Causes of Coronary Artery Disease
Coronary artery disease recognizes atherosclerosis and its vascular effects (thrombo-embolism) as the main causes and, less common causes, coronary vasculitis and episodes of coronary spasm.
If the cause of myocardial ischemia is coronary artery disease, then the causative factors of the latter are, indirectly, also the causal factors of the myocardial ischemia itself.
ATHEROSCLEROSIS AND MYOCARDIAL ISCHEMIA
Atherosclerosis is the process of hardening and thickening of the arteries of medium and large caliber, which over time induces 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 lesions a coagulation process arises which, by recalling platelets in place, has the involuntary effect of expanding the atheroma itself (thrombosis), thus worsening the extent of the vessel narrowing. more emboli, that is mobile bodies which, circulating freely in the blood, can lead to the complete occlusion of a blood vessel of the same size, even at a considerable distance from the site of origin.
On the basis of what has just been stated, when they are related to atherosclerosis, the phenomena of coronary artery disease and myocardial ischemia may depend on an atheroma inside the coronary arteries - atheroma which, following an injury, has attracted platelets, has grown further and resulted in occlusion - or from a circulating fragment in the blood of an atheroma located in a vessel other than the coronaries.
Causes and risk factors of atherosclerosis:
- Hypertension
- Hypercholesterolemia
- High triglycerides
- Old age
- Cigarette smoking and tobacco addiction
- Diabetes mellitus
- Obesity
- Inflammatory diseases such as systemic lupus erythematosus
CORONARY VASCULITIS
In medicine, the word "vasculitis" means inflammation of the vascular walls; consequently, with coronary vasculitis, doctors mean inflammation of the walls of the coronary arteries.
Currently, the precise cause of coronary vasculitis episodes is unclear; it is a fact, however, the existence of a correlation between inflammations 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);
- Blood cell tumors (eg leukemia).
SPASMOVASCULAR CHARACTERISTICS OF THE CORONARIES
Coronary spasm is the sudden narrowing of a coronary artery, due to the abrupt and sudden contraction of the muscular component of a portion of the vessel wall.
Various factors can trigger / promote coronary spasms, including:
- The use of drugs such as cocaine, amphetamines and methamphetamines;
- Excessive exposure to cold;
- Strong emotional stresses;
- Tobacco smoke.
Risk factors
Risk factors for myocardial ischemia are:
- The causes / factors favoring atherosclerosis (eg: hypertension, old age, cigarette smoking, diabetes mellitus, obesity, etc.);
- Conditions associated with episodes of coronary vasculitis (hepatitis B, rheumatoid arthritis, etc.);
- Factors known to induce coronary spasm (ex: drug use, excessive exposure to cold, etc.).
Types of Myocardial Ischemia
Myocardial ischemia can have a transitory character - 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 coronary occlusion and, finally, the death of the heart muscle.
The first type of myocardial ischaemia (transient myocardial ischaemia) is an example of angina pectoris, while the second type of myocardial ischaemia (permanent myocardial ischaemia) is an example of myocardial infarction (or heart attack).
It is easy to understand, among the forms of myocardial ischemia just mentioned, the most serious and with the most dangerous consequences is myocardial infarction.
Therefore, several other manifestations can be added to chest pain, including:
- Pain in the shoulder and / or left arm;
- Pain in the back, neck and / or jaw;
- Dyspnea, i.e. shortness of breath or wheezing
- Tachycardia, that is, an increase in respiratory rate;
- Profuse sweating;
- Dizziness;
- Limitation of physical abilities, with a sense of fatigue 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 particular symptoms or signs.
The "absence of symptoms by a" myocardial ischemia is a very dangerous event, because it prevents the patient from realizing that he is ill and that he needs appropriate treatment.
Why does myocardial ischemia cause symptoms?
The symptoms of myocardial ischemia are the manifestation of the greater fatigue that the myocardium encounters in pumping blood into the circulation, after it receives a quantity of oxygenated blood lower than it 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, ie the death of its constituent cells.
The death of the myocardium is an irreversible event and seriously compromises the functions of the heart, so much so as to be fatal for the patient in a fair number of cases.
Specifically, the complications attributable to the presence of permanent myocardial ischemia include severe cardiac arrhythmias (eg left ventricular fibrillation) and heart failure.
Remember: myocardial death due to permanent myocardial ischemia coincides with myocardial infarction.
Hence, in addition to permanence, what distinguishes heart attack from angina pectoris is the death of the heart muscle tissue.
When to see a 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 consult a doctor, or go to the nearest hospital , the apparently unjustified appearance of chest pain, associated with problems such as dyspnea, nausea, profuse sweating, vomiting, sense of anxiety, pain in the shoulder and / or left arm, dizziness, etc.
, echocardiogram, electrocardiogram, stress test, blood tests, coronary angioTAC and coronary angiography.Report of symptoms, physical examination and anamnesis
- The report of the symptoms by the patient 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 path;
- 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 changes in the myocardium due to "myocardial ischemia and" coronary occlusion that caused the aforementioned ischemic phenomenon.
Electrocardiogram
The electrocardiogram evaluates the heart rate, which is the rhythm at which the heart beats.
An "eventual abnormality in the heart rate could be the signal of the reduced blood supply to the myocardium observable in the occurrence of a" myocardial ischaemia.
Stress test
The stress test is an assessment, in a controlled environment, of the effects of physical activity on the patient and on the patient's heart.
If physical activity is associated with easy breathlessness and fatigue, the heart is very likely not performing 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 when myocardial necrosis occurs.
Coronary angioTAC
Coronary angioTAC is a radiological examination that allows the study of blood circulation in the coronary arteries.
In a context of myocardial ischaemia, it provides information on the degree of coronary occlusion.
Coronarography
Coronary angiography is a radiological examination that allows to specifically analyze the blood flow inside the coronary arteries and precisely identify the location and severity of a possible occlusion.
In a context of myocardial ischemia, coronary angiography represents the diagnostic confirmation test par excellence.
Pharmacological therapy
Among the drugs used in the presence of myocardial ischemia, there are:
- Anticoagulants (eg heparin) and antiplatelet agents (eg aspirin). They are beneficial because they improve the symptom picture, 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 dilating effects on coronary arteries, but it is only effective in the middle of an episode of angina pectoris or myocardial infarction.
- Beta-blockers, ACE inhibitors and angiotensin II receptor antagonists are useful in the presence of myocardial ischaemia associated with hypertension, as their intake induces a reduction in blood pressure.
- Statins. They are of benefit in the presence of myocardial ischaemia related to hypercholesterolemia, as their intake produces a reduction in cholesterol levels.
Surgical therapy
Among the surgical treatments suitable for countering the phenomenon of myocardial ischemia, there are angioplasty with stenting coronary artery and coronary artery bypass surgery.
Did you know that ...
In some particular cases of myocardial ischemia, doctors consider it essential to resort to both the use of drugs and surgery.
ANGIOPLASTIC WITH STENTING CORONARY
Angioplasty is the medical procedure that allows to eliminate or, at least, reduce the narrowing or narrowing of a blood vessel, through the use of a particular catheter.
The stenting, on the other hand, consists in the placement of a metal prosthesis (stent) inside a blood vessel - previously occluded and reopened by angioplasty - in order to keep it open over time and avoid second occlusions.
In a context of myocardial ischemia, it is possible to understand "angioplasty with stenting has as its object the coronary or coronary arteries victims of occlusion.
CORONARY BYPASS
Coronary artery bypass surgery consists in creating an alternative path for the passage of blood to the occluded one, by means of the insertion of a new coronary vessel.
In other words, during a coronary bypass surgery, the operating doctor inserts a new coronary artery, the purpose of which is to replace the obstructed original coronary artery in the functions.
Coronary artery bypass grafting is a rather delicate surgical procedure, reserved for the most severe cases of myocardial ischaemia.
