The role of electrocard centers in the diagnosis of myocardial infarction

The article was consulted professionally by Specialist Doctor II Le Dang Van – General Internal Medicine Doctor – Department of Medical Examination and Internal Medicine – Share99 Hai Phong International Health Hub.

Myocardial infarction is the leading cause of death in the world today. The diagnosis of myocardial infarction plays an important role in the orientation of treatment and minimizes mortality from the disease. In particular, diagnosis based on electrocardiinal changes in the electrocardigraphy is one of the main standards in determining myocardial infarction.

1. What is an electrolysym?

Electrocardiogram (ECG) is a graph that records changes in the current inside the heart. The heart contracts to the rhythm and is controlled by a conduction system in the myocardial muscle.

The currents of the heart are very small, only about a thousand volts but can be traced from the electrolyts placed on the hands, legs and chest of the patient transmitted to the recorder.

The electric recorder will amplify the signal and record it on the electrolysic. Electrocard centers are often used in medicine to detect cardiovascular diseases such as arrhythmias, heart failure, myocardial infarction …

2. How to diagnose myocardial infarction with an electrocardigraphy?

When the heart muscle is anemia and lack of nutrients, leading to damage or necrosis of the heart muscle, the electrical conduction of the heart muscle will change. This change can be noted on the electrolysym, which is one of the factors that make up the value of this sub-clinical method.

For the diagnosis of myocardial infarction,it is necessary to observe a chain of beats and 12 trajectory on the electrocardigraph. Diagnosis of myocardial infarction when electrocardigraph imaging has: st segment up to ≥ 1mm in ≥ 2 adjacent trajectories. It is usually accompanied by a st section that spreads down the mirror at side-to-side trajectories. In V2, V3 for accurate diagnosis, ST is required to increase to 2mm in men and 1.5mm in females. Thus, the characteristic variations in myocardial infarction shown through the electrocardigraph include:

  • ST segment increased in damaged myocardial area
  • ST segment down in opposite trajectories (mirroring)
  • Appearance of Q-wave pathology
  • R-wave with amplit margin reduced
  • T-waves are reversed.

Diagnostic standards of acute myocardial infarction on the electrocardigraphy:

  • Q-wave pathology: the time of Q > 0.04 seconds Q wave amplit > 25% R wave and switch
  • The ST section looks at the infarction area and "mirrors" in opposite trajectories
  • Deep and symmetrical T-waves in the vaginas associated with the myocardial region with infarction

The role of electrocard centers in the diagnosis of myocardial infarction

Diagnosis of myocardial infarction by electrocardiary

3. Determination of the stage of myocardial infarction by electrocardigraphy

When coronary insular function occurs suddenly, it may be due to a stress (emotional, exertion, cold …) that acts on the body, a myocardial infarction may arise. Normally, the myocardial region with an infarction will have a necrotic middle area, then a lesion area surrounding it and, in addition, an anethal region surrounding the lesion area. On the electrocardigraphy image myocardial infarction will get all 3 types of those signs but not at the same time but often change through the three main stages are the stages of myocardial infarction:

Phase 1 (level):

Occurs in the first 1.2 days.

Arched waves: may have appeared pathology Q waves, long QT segments.

Phase 2 (semi-level):

From a few days to several weeks is the most common stage: the ST segment spreads lower, the T-wave is deep, pointed, symmetrical (called the Pardee rim wave). At the same time, the Q wave is pronounced and the QT segment is longer.

Stage 3 (chronic)

  • From a few months to several years: the ST segment is co-electric, the T wave can be positive or still negative, and the pathology Q wave usually persists forever.

4. Specific assessment of myocardial infarction by electrocardigraph

The signs on the ationed electrocardigraphy are not present in all the same trajectory, but are only visible in the vagina with the electrolyses placed (direct redirection) on top of the myocardial region with an infarction. So they call those signs direct images.

On the contrary, a vagina with an electrolyte placed in the opposite hexro centre of the infarction zone will receive contradictory signs of the above signs, also known as "mirror images" or "indirect images".

Infarction can appear in various narrow areas of the left left erth (right is rarely suffered). Depending on the damaged area, the electrolysynthies can be classified into a variety of infarctions with the following stage 2 (substecular) signs:

Pre-septal infarction – infarction in the left front wall and the front of the septum:

  • Live images: QS, ST waves, T-negative waves in V2, V3, V4.
  • Sometimes low or negative T waves in V5, V6, aVL, D1 (T1>T3) due to anemia spread to the left (left) side of the left isthle.

Frontal – side infarction: infarction in the outer part of the front and side cities of the left atath:

The role of electrocard centers in the diagnosis of myocardial infarction

The role of electrocard centers in myocardial infarction
  • Live images: deep and wide Q waves, ST segments, deep negative T waves in V5, V6, D1, aVL.
  • Indirect image: ST segment spreads down, positive T waves are very high in D3, sometimes in aVF.

Post- lower infarction: infarction in the back and lower cities of the left erth:

  • Live images: deep, wide Q waves, st segment spread up, deep negative T waves in D3, aVF, sometimes even D2.
  • Indirect image: high positive T wave, can be pointed, symmetrical, ST segment can be reduced in V1, V2, V3, V4.

Intridinal infarction (left erthinal):

  • Mainly front-side: ST segment spreads down, sometimes T waves deform in V5, V6, D1, aVL.
  • Sometimes the following member below: ST spreads down in D3, D2, aVF.

Myocardial infarction has additional branching:

In many cases, coronary insular insular infarction also causes a branch of his bundle to be poorly nourished, spawning a branch, signs of branching will coordinate with the basic signs of myocardial infarction.

  • Left branch + infarction front – side: Block left branch.
  • Right branch + following infarction – below: deep Q waves in D3, D2 + rSR' form in V1, V2.
  • Right branch + infarction in front of the wall: In V1, V2, V3 (V4) there is a QR form with a late intular branch.

An electrocardigraphy is a technique that helps diagnose myocardial infarction effectively. This technique is being successfully applied by Share99 International Health Hub in examining and diagnosing a variety of cardiovascular diseases in general and myocardial infarction in particular.

Specialist Doctor II Le Dang Van has more than 20 years of experience in the field of internal medicine. Especially experienced in cardiovascular specialty and high pressure oxygen treatment. Currently a doctor of General Internal Medicine Department of Share99 Hai Phong International Health Hub.


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About: Minh Quynh

b1ffdb54307529964874ff53a5c5de33?s=90&d=identicon&r=gI am the author of I had been working in Vinmec International General Hospital for over 10 years. I dedicate my passion on every post in this site.


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