Causes of myocardial necrosis

Acute myocardial infarction contributes to the development of necrosis of the heart muscle. This occurs as a result of acute coronary insufficiency caused by the sudden cessation of blood flow through a coronary artery or insufficient amount of oxygen and nutrients consumed by the myocardium.

Myocardial infarction can cause blockage of one of the vessels by a blood clot that forms in the area of the atherosclerotic plaque. You must understand that for heart ailments always needed extra help at the first symptoms you must seek help to the doctor, because this insidious disease progresses quickly.

Code the clot blocks the vessel feeding the heart, oxygen supply lasts for 10 seconds. Then another 30 minutes, the heart muscle is viable and during this short period it is still possible to save the heart with the help of intensive therapy. But if you do not assist, then begin the irreversible changes in the cells after 3-6 hours from the onset of impaired patency of blood vessels of the heart muscle in this area is killed.

Necrosis can affect the entire thickness of the myocardium (transmural) or captures a small area, depending on the size of necrotic areas referred to as – large and small focal infarction. The clinical picture of myocardial infarction is complex and diverse, it is difficult to establish the correct diagnosis in the shortest possible time.
The identification of the diagnosis based on three characteristic parameters:

· typical pain syndrome

· ECG changes

· changes of parameters of biochemical analysis of blood

Pain, the first symptom of this disease, it may be different in intensity and duration. A person can feel prolonged squeezing, crushing pain behind the breastbone in the region of the heart, radiating to arm, neck, back area blades, but the symptoms may be discomfort and disruption of the heart.

Sometimes pain is entirely absent and only the pale skin, cold sweat and fainting is a signal of disease. In difficult diagnostic cases, when the disease is manifested by difficulty in breathing with shortness of breath and abdominal pain. Daily cardiologists foster hospital departments diagnose patients who applied with complaints of pain in the thoracic spine.

If during the examination there are problems with the diagnosis then it is necessary to produce the serum markers of myocardial necrosis. Identify the level of markers of myocardial necrosis helps determine the severity of the condition and to choosethe most favorable treatment.

The types of markers of myocardial necrosis

There are criteria requirements for biochemical marker:

· high specificity;

· high sensitivity to myocardial necrosis;

· achieving a significant level in a short time from the start of symptoms and the preservation of it in a few days;

Unfortunately, while this one is the perfect token of having all of these criteria does not exist.

For the diagnosis of myocardial infarction is used:

1. Early marker:

· myoglobin – muscle protein complex, linking a portable hemoglobin oxygen with the formation of oxymyoglobin, provides the working muscles with enough oxygen. This so-called respiratory pigment in human muscle tissue, its concentration in serum is increased within 2 h after the onset of symptoms of infarction. As a separate token is not used because of the low specificnosti.

· cardiac form of creatine phosphokinase( CPK) is also present in human muscle tissue, to diagnose THEM, determine the mass of this enzyme and not its activity, because it has low specificity for myocardial necrosis. Appears in the serum after 3-4 hours after the start of pathological processes.

· cardiac form of the protein that binds fatty acid has sensitivity in the detection of myocardial necrosis;

2. Late marker has high specificity and displays the diagnostic result after 6-9 hours :

· lactate dehydrogenase (LDH) is a cytosolic protein with five isoenzymes. Due to recent increases concentration in the serum marker LDH is not used in the early diagnosis of myocardial infarction.

· aspartate aminotransferase (AST) – contains the liver, has a low specificity for myocardial necrosis. For diagnostics used in combination with normal and specific markers.

· heart troponin I and T - high specificity and sensitivity allows us to call this token the "gold standard"for biochemical research. Currently, this is the most convincing marker.

The duration of detection of the marker helps to clarify the diagnosis of myocardial infarction in the later stages. To determine the exact stage of the disease examined"short-lived" markers of necrosis. Biomarkers of myocardial necrosis are measured in all patients with symptoms of acute coronary syndrome.