Điện tâm đồ trong nhồi máu cơ tim.PPT

Điện tâm đồ
trong nhồi máu
cơ tim
TS. Đinh Hiếu Nhân
Acute Myocardial Infarction
•
ST segment elevation MI – persistent complete occlusion of an
artery supplying a significant area of myocardium without adequate
collateral circulation
•
UA/NSTEMI – result from non-occlusive thrombus, small risk area,
brief occlusion, or an occlusion with adequate collaterals
I. Chẩn đoán NMCT
ECG trong NMCT
•
Chẩn đoán (+) NMCT cấp có ST chênh lên.
•
Chẩn đoán giai đoạn NMCT cấp.
•
Chẩn đoán vùng NMCT.
•
Chẩn đoán biến chứng RLNT
ECG changes in AMI
•
In the early stages of AMI the ECG may be normal
•
<50% of patients with AMI have clear diagnostic
changes on their first trace.
•

About 10% of patients with a proved acute myocardial
infarction fail to develop ST segment elevation or
depression.
•
In most cases, however, serial ECG’s show evolving
changes that tend to follow well recognised patterns.
Biến đổi ECG trong NMCT
•
ST – T chênh lên.
•
Sóng Q bệnh lý
J point
ST segment
Last deflection of QRS
Sự tạo thành các biến đổi của sóng ECG
trong NMCT
Tạo thành sóng Q
Tạo thành đạon ST chênh lên hay chênh
xuống
Đoạn ST
•
ST segment of the cardiac cycle represents the period between
depolarization and repolarization of the left ventricle
•
In normal state, ST segment is isoelectric relative to PR segment
Minnesota Code
•
The Minnesota code 9-2 requires ≥1 mm ST elevation in one or more
of leads I, II, III, aVL, aVF, V5, V6, or ≥ 2 mm ST elevation in one or
more of leads V1–V4

•
Menown IB, Mackenzie G, Adgey AA. Optimizing the initial 12-lead electrocardiographic
diagnosis of acute myocardial infarction. Eur Heart J 2000; 21 (4):275-83.
•
Đoạn ST chênh lên ở ít nhất 2 chuyển đạo kế tiếp nhau
ST Segment
Elevation
Acute Myocardial Infarction
•
Irrespective of which definition is used, ST elevation has poor
sensitivity for AMI where up to 50% of patients exhibit ‘atypical’
changes at presentation including isolated ST depression, T inversion
or even a normal ECG
•
Menown IB, Mackenzie G, Adgey AA. Optimizing the initial 12-lead electrocardiographic
diagnosis of acute myocardial infarction. Eur Heart J 2000; 21 (4):275-83.
How To Differentiate STE due to
AMI from Other Causes?
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Magnitude of the elevation
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Morphology
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Distribution
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Prominent Electrical Forces (Voltage Amplitude)
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QRS width
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Other Features

Morphology of the ST
Elevation
Variable Shapes Of ST Segment
Elevations in AMI
Goldberger AL. Goldberger: Clinical Electrocardiography: A Simplified Approach. 7th
ed: Mosby Elsevier; 2006.
Morphology of STE
•
Concave shape STE – non AMI causes
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AMI causes – usually demonstrate convex/straight STE
J point
Apex of T wave
Concave STEConvex STE
Notching or slurring of J
point
Concave STE
Benign Early Repolarization
Large amplitude T
wave
Benign Early Repolarization
•
ECG characteristics:
1. STE <2 mm
2. Concavity of initial portion of the ST segment
3. Notching or slurring of the terminal QRS complex
4. Symmetrical, concordant T wave of large
amplitude
5. Widespread or diffuse distribution of STE
o

Does not demonstrate territorial distribution
1. Relative temporal stability
Distribution
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STE due to AMI usually demonstrate regional or territorial pattern
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Examples:
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Anterior MI – V3-V4
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Septal MI – V2-V3
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Anteroseptal MI – V1/2 – V4/5
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Lateral MI – V5/V6
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Inferior MI – II, III, aVF
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Diffuse STE – non AMI causes, e.g. pericarditis
Lateral Wall MI: I, aVL, V5, V6
Source: The 12-Lead ECG in Acute Coronary Syndromes, MosbyJems, 2006.
Inferior Wall MI II, III, aVF
Source: The 12-Lead ECG in Acute Coronary Syndromes, MosbyJems, 2006.