ECG
ECG stands for electrocardiograph. It gives a graphical representation of the electrical activity of the heart during a cardiac cycle which helps to further detect the abnormalities and help us to measure the functioning of the heart. To obtain a standard ECG graph, a patient is connected to the machine with three electrical leads, one to each wrist and to the left ankle, that continuously monitor the heart activity and functioning. The human heart produces an electrical impulse passing through our heart, it generates an electrical impulse by itself.
Explanation of ECG Different Waves
There are mainly three different types of ECG is performed:
Resting ECG: When your body is in resting state. Under this type machine examine your heart beat during resting condition.
Ambulatory ECG: This type of ECG is conducted for 24 hours. The heart’s electrical impulses are measured by a device called the Holter Monitor.
Cardiac Stress Test: This test is used to measure ECG when you are on an exercise bike.
Different Types of Waves Produced by Electrocardiogram
The P-Wave
It represents the electrical excitation (or depolarisation) of the atria, which leads to the contraction of both the atria. Features of P - Wave P duration < 0.12 secP amplitude < 2.5 mm Frontal plane P wave axis: 00 to +750 May see notched P waves in frontal plane
The QRS Complex
It represents the repolarization of the ventricles, which initiates the ventricular contraction. Features of QRS Complex QRS duration ≤ 0.10 secQRS amplitude varies from lead to lead and also from person to person. Two determinants of QRS voltages are:Size of the ventricular chambers (i.e., the larger the chamber, the larger the voltage)Nearness of chest electrodes to ventricular chamber (the closer, the larger the voltage)
T-Wave
It represents the return of the ventricles from excited to normal state (repolarisation) and the end of the T-wave marks the end of systole. The normal peak of the T wave is usually in the same direction as the QRS wave except in the right precordial leads. In the normal ECG the T wave is always upright. By counting the number of QRS complexes that occur in a given time period, a person can determine the heart beat rate of an individual.
ECG Graph
Electrocardiograph Machine Includes
They have small sticky electrodes attached to the arms, chest, legs. These electrodes are connected to the ECG machine with the help of wires that help in detecting the electrical impulses occurring at each heartbeat. These electrodes can detect every minute form of changes happening in heart muscles and draw every depolarising pattern of heartbeat on a graph.
Feature of Normal ECG Heart beat should be in between 60-90 beats per minute (bpm).
PR Interval: 0.12 - 0.20 sec
QRS Duration: 0.06 - 0.10 sec
QT Interval (QTc ≤ 0.40 sec)
(Image will be uploaded soon)
Why is an ECG Done?
ECG is done to determine or detect Abnormal heart rhythm (arrhythmias)
If there are any blocked or narrowed arteries in your heart (coronary artery disease) are causing chest pain or a heart attack.
To find whether you have had a previous heart attack or not.
To monitor if the medicines are causing any side-effects to our body system.
Medical Use of ECG
The main function of ECG is to obtain information regarding the heart impulse. There is a great medical use of this information regarding your health issues like:
Chest pain Shortness of breath Light
headedness Dizziness Fainting spells It is also required prior to any type of heart surgery, including surgery for pacemaker placement.
MCQ Questions on ECG
1. ECG (Electrocardiogram) Was Developed First By
(a) Wilhelm His
(b) Steward
(c) Hubert Mann
(d) Willem Einthoven
Answer: (d)
2. This Is the Classic ECG Change in MI (Myocardial Infarction)
(a) ST-segment elevation
(b) T-wave inversion
(c) Development of an abnormal Q wave
(d) All of these
Answer: (d)
3. In Which of These Conditions Can Widened QRS and Tall-Tented T Waves Be Observed
(a) Hyponatremia
(b) Hyperkalemia
(c) Hyperglycemia
(d) Hyperphosphatemia
Answer: (b)
4. A Particular ECG Change Observed in Hypokalemia is
(a) ST Segment elevation
(b) U Wave(a position deflection after the T wave)
(c) Tall peaked T waves
(d) Widening of the QRS complex and increased amplitude
Answer: (b)
5. ECG Report Must Consist of the Following Information
(a) Rhythm, cardiac axis
(b) Conduction intervals
(c) Description of the ST segments, QRS complexes, T-waves
(d) All of these
Answer: (d)
6. For the Normal Heartbeat, Depolarization Stimulus Originates In
(a) His-bundle areas
(b) Epicardium
(c) Sinoatrial (SA)node
(d) Atrioventricular (AV) node
Answer: (c)
7. The Characteristics – Slurring of the Initial QRS Deflection, Shortened PR Interval, and Prolonged QRS Duration Are of This Condition
(a) Atrial tachycardia
(b) Left bundle branch block
(c) WPW (Wolff-Parkinson-White) syndrome
(d) Myocardial ischemia
Answer: (c)
8. P Wave Indicates
(a) Depolarization of right ventricle
(b) Depolarization of left ventricle
(c) Depolarization of both atria
(d) Atrial to ventricular conduction time
Answer: (c)
9. Ventricular Muscle Depolarization Is Indicated By
(a) PR interval
(b) P wave
(c) U wave
(d) The QRS complex
Answer: (d)
10. ECG Identified by the PR Interval Tends to Become Longer With Every Succeeding ECG Complex Until There Is a P Wave Not Followed by a QRS is Observed in
(a) Third-Degree Atrioventricular Block
(B) Second-Degree Atrioventricular Block, Type II
(C) Second-Degree Atrioventricular Block, Type I
(D) First-Degree Atrioventricular Block, Type II
Answer: (c)
What is Electrocardiogram?
The process by which an electrocardiogram is produced is known as electrocardiography. The process involves a graphical representation of the Heart impulses. In simple words, a graph of voltage versus time of the electrical activity of the heart using electrodes which are placed on the skin is known as an electrocardiogram. The electrodes used in this particular process are used to detect the small electrical charge that are the consequences of the cardiac muscle depolarization followed by repolarization.
Medical Uses Related to Heart Cardiography
This particular process helps in a lot of medical uses which are related to heart issues. Some of the common medical issues which are solved using this particular process can be listed as described below:
This process is carried out in times when a person gets chest pain or myocardial infarction which is also known as heart attack. This this includes ST elevated myocardial infarction (STEMI) or non ST elevated myocardial infarction (NSTEMI)
If a person has shortness of breath or murmurs, fainting seizures, funny turns or have arrhythmias, then the process is very useful in order to know the internal issues which are causing the particular symptoms.
It is highly useful in cardiac stress testing.
It is highly used in electrolyte abnormalities such as hyperkalemia.
CTA (computed tomography angiography) MRA (magnetic resonance angiography) of the heart are done by the following process which we know widely as electrocardiography.
The world in recent times has recorded a large number of people losing their life due to heart infarction. This process is carried out sometimes in a continuous monitoring process for the most ill patients, those who need special care and medical attention.
FAQs on Electrocardiograph
1. What is the full form of ecg?
ECG stands for electrocardiograph.
2. How many different types of wave are there in ecg?
There are mainly three types of ECG peak:
The P-wave represents the depolarisation of the atria, which leads to the contraction of both the atria.
The QRS complex represents the depolarisation of the ventricles, which leads to the ventricular contraction.
The T-wave represents the return of the ventricles from excited to normal state that is repolarisation and the end of the T-wave marks the end of systole.
3. How is ecg helpful ?
ECG (electrocardiogram) measures or records the electrical activity of our heart at rest and also it provides information about our heart rate and rhythm.
It further shows if there is any enlargement of the heart due to high blood pressure (hypertension).
4. Why is ecg done?
ECG is done because of following reasons:
To detect any heart related issues.
To detect whether you have had any heart attack.
To find out if any medicine is causing any side effect on our body.
To know if there are any blocked arteries.
5. Explain different types of ecg?
There are mainly three different types of ECG is performed:
1. Resting ECG: when your body is in resting state.under this type machine examine your heart beat during resting condition.
2. Ambulatory ECG: This type of ECG is conducted for 24 hours. The heart’s electrical impulses are measured by a device called the Holter Monitor.
3. Cardiac Stress Test: This test is used to measure ECG when you are on an exercise bike.
6. Define some differences between electrocardiogram and echocardiogram.
Both electrogram and electrocardiogram and echocardiogram is used to monitor the heart pulse rate. The major difference which differentiate these two factors is that they give two different tests. Electrocardiogram is used to measure the abnormality in the heart electrical impulses which are done by using the electrodes and placing them in the skin. On the other hand the echocardiogram helps to measure irregularities in the heart structure using an ultrasound.
7. How do you prepare for an electrocardiogram?
In order to prepare yourself for an electrocardiogram you need to follow some of the major steps which are described as below:
Strictly avoid oily or greasy skin creams or lotions during the day you are going to have the electrocardiogram test. This is due to the fact that it causes an interference between the electrodes and skin contact.
Any full-length hosiery is strictly avoided, this is because the electrodes are placed directly on the legs and it would create interference if you would be wearing some full length hoiseries.
Very comfortable shirt which is easily removable in order to place the leads on the chest.
These are some of the important points which you should keep in mind when you are going for an electrocardiogram test.
8. What happens during an echocardiogram?
this particular test also is used to measure the heart pulses. Echocardiogram is a graphical representation of the outlines of the heart's moment. This particular test is carried out under the influence of ultrasound(high frequency sound waves). The process carries out in a different step mentioned below:
A hard held wand will be placed on your chest in order to get the picture of the hearts valves and chambers.
This particular process helps the sonographer to evaluate the pumping action of the heart.
9. Are you awake during a transesophageal echocardiogram?
The following steps will be carried out in order to make the process easier:
While carrying out echocardiogram, a person is given a sedative which would help the patient to relax so that the echocardiogram will be easier.
The patient should be given a number of medications also which should be sprayed down her or his throat.
This number in medication helps the transesophageal ultrasound more comfortable.
You will be able to awake enough to swallow if necessary.
10. What is the P wave on electrocardiogram?
In order to represent the electrical depolarization of the atria of the heart, P waves aur PR segment is used. This is an integral part of an electrocardiogram. The p waves are typically a small positive deflection from the isoelectric baseline which occurs just before the QRS complex.
