ECG READING EXERCISES-K-MODEL ECG IN HEART ATTACKS

ECG IN ANGINAL ATTACKS

In this article we are to practice the interpretation of ECG reports during various conditions of angina pectoris.

Angina is caused by the imbalance between the supply and demand of oxygen by the arteries of the heart muscles (Coronary Arteries). When the demand exceeds supply the affected area of the heart muscle becomes darkened and weakened to act. This condition is called ischemia. This may result in chest pain.
Some people may suffer from angina but on examination there is no visible ischemia on their heart muscle. This may be due to hidden ischemia in the endothelium of the heart muscle which may be due to the block in micro-arteries of the endothelium.

Angina itself is not life-threatening but if it is left untreated it may precipitate a heart attack.

Anginas are many types but the serious one is the suddenly unstable angina.

Types of Angina:-

1.Unstable Angina-More dangerous and a prediction of an immediate heart attack. It is due to coronary artery blockage by clots, atherosclerosis, or by any other means like an air bubble.

2. Stable Angina-It is less severe than unstable angina. It occurs when a person does some work like running, physical exercise, or any other routine work. A brief rest can relieve anginal pain. But the pain may revert again if the person resumes the work.

3. Microvascular, Variant, or Prinzmetal Angina-These are less severe and less serious but proper food control with doctor's advice is necessary.

RISK FACTORS

1.Diabetes Mellitus

2.Cigarette Smoking

3.High Cholesterol

4.High B.P

5.LifeStyles

6.Family History

7.Kidney Failure

8.Over Stress

9.Obesity.

Model ECG in Unstable Angina:-

Fig-1A

Fig 1B

It is very easy to recognize the presence of Unstable Angina (UA) in ECG. The main recognizable feature is ST-segment depression. Check the model ECG in Fig-1B and inspect the ST-depression marked with a small red circle both in lead II and in lead V3.

Lead V3 shows the depression very clearly as it views the heart more closely from the lateral left side.
The exact appearance of ECG waves is simulated in Fig 1A. Compare the images of Fig-1B with Fig 1A.

ECG in Stable Angina:-

Fig 2A

Fig 2B

In Fig-2A and Fig 2B two ECG models taken in patients with Stable Angina have been presented.
Stable Angina or SA is the condition that occurs when the patient is at work and disappears when the patient is at rest.
In the above two figures the ECG waves are normal at rest and show ST-segment depressions after some physical activities such as routine home or office works or lifting something or running etc.etc.The depressions have been marked by small red circles in Fig-2B.

MICROVASCULAR ANGINA

Fig-3

Microvascular angina occurs when tiny arterial blood flow is blocked by clots, atherosclerosis, or air bubbles.

In a similar manner we can understand variant or Prinzmetal anginas. These three anginas can escape from diagnosis and can be detected by ECG examinations which shows typical ST-segment depressions as shown above.

Commonly all anginas have common symptoms like chest pain or chest pressure radiate from the left arm, followed by sweating headache, nausea, vomiting, and loss of consciousness.

Continued...