Paper English 3 EKG & Echo
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Transcript of Paper English 3 EKG & Echo
ELECTROCARDIOGRAPHY AND ECHOCARDIOGRAPHY
Fadillah Nur Herbuono
030.06.085
Medical Faculty of Trisakti University
Jakarta
2010
PREFACE
This paper, titled “Electrocardiography And Echocardiography”, I arranged in order
to complete my English assignment for subject medical English 3 in the faculty of medicine,
trisakti university.
I arrange this paper so simple in order to make these topics easier. I hope this paper’s
topics is compatible and can give the information which needed by friends or everybody as
medical student and physicians both here and abroad.
I realized that this paper is too far from perfect, but I have tried to arrange this paper to be
good enough for us as medical student. I hope all the readers who had read this paper will
continue to find all of things about these topics. So their knowledge didn’t come only from
this paper, but all the information from the other sources.
With this time, I would like to say thank you to my teacher, DR. Dr. H. Ardiyan Boer, Sm.
Hk. who taught and helped, my friends, and everybody who helped and inspiring me during
the process of making this paper so I can finished this paper. Finally I hope this paper can be
useable for us.
Thank you
2
ABSTRACT
Electrocardiography and Echocardiography are diagnostic tool that very useful for
determining whether a person has heart disease. The electrocardiogram (ECG or EKG) is a
diagnostic tool that measures and records the electrical activity of the heart in exquisite detail,
gives a graphic recording of the electric forces generated by the heart during depolarization
and repolarization. Interpretation of these details allows diagnosis of a wide range of heart
conditions. These conditions can vary from minor to life threatening. And Echocardiography
is a unique non-invasive method for imaging the living heart, to create a moving picture of
the heart, to make images of the heart chambers, valves and surrounding structures. It is
based on detection of echoes produced by a beam of ultrasound (very high frequency sound)
pulses transmitted into the heart.
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INTRODUCTION
The electrocardiogram (ECG or EKG) is a diagnostic tool that measures and records the
electrical activity of the heart in exquisite detail. Interpretation of these details allows
diagnosis of a wide range of heart conditions. These conditions can vary from minor to life
threatening.
The term electrocardiogram was introduced by Willem Einthoven in 1893 at a meeting of the
Dutch Medical Society. In 1924, Einthoven received the Nobel Prize for his life's work in
developing the ECG.
The ECG has evolved over the years.
The standard 12-lead ECG that is used throughout the world was introduced in 1942.
It is called a 12-lead ECG because it examines the electrical activity of the heart from
12 points of view.
This is necessary because no single point (or even 2 or 3 points of view) provides a
complete picture of what is going on.
To fully understand how an ECG reveals useful information about the condition of
your heart requires a basic understanding of the anatomy (that is, the structure) and
physiology (that is, the function) of the heart.
And Echocardiography is a unique non-invasive method for imaging the living heart. It is
based on detection of echoes produced by a beam of ultrasound (very high frequency sound)
pulses transmitted into the heart.
4
From its introduction in 1954 to the mid 1970's, most echocardiographic studies employed a
technique called M-mode, in which the ultrasound beam is aimed manually at selected
cardiac structures to give a graphic recording of their positions and movements. M-mode
recordings permit measurement of cardiac dimensions and detailed analysis of complex
motion patterns depending on transducer angulation. They also facilitate analysis of time
relationships with other physiological variables such as ECG, heart sounds, and pulse
tracings, which can be recorded simultaneously.
A more recent development uses electromechanical or electronic techniques to scan the
ultrasound beam rapidly across the heart to produce two-dimensional tomographic images of
selected cardiac sections. This gives more information than M-mode about the shape of the
heart and also shows the spatial relationships of its structures during the cardiac cycle.
A comprehensive echocardiographic examination, utilizing both M-mode and two
dimensional recordings, therefore provides a great deal of information about cardiac anatomy
and physiology, the clinical value of which has established echocardiography as a major
diagnostic tool.
This unit covers the principles of two-dimensional echocardiography in more detail; it
explains the normal two-dimensional recordings in terms of the anatomy of the cardiac
sections scanned by the ultrasound beam. Some supplementary M-mode recordings are
included. Subsequent units will discuss applications of both M-mode and two-dimensional
echocardiography in acquired and congenital disease.
5
References Review
I. ELECTROCARDIOGRAPHY (ECG)
Definition(1)
A galvanometer and electrodes with six limb leads and six chest leads. Gives a graphic
recording of the electric forces generated by the heart during depolarization and
repolarization. The electrocardiogram is recorded on graph paper with divisions.
Terminology(1)
- Depolarization:
Electrical activation of the myocardium.
- Repolarization:
Restoration of the electrical potential of the myocardial cell.
- P wave:
ECG deflection representing atrial depolarization. Atrial repolarization occurs during
ventricular depolarization and is obscured.
- QRS wave:
ECG deflection representing ventricular depolarization.
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- T wave:
ECG defection representing ventricular repolarization.
- Normal R Wave Progression:
Vl Consists of a small R wave and a large S wave, whereas V6 consists of a small Q wave
and a large R wave. Since V3 and V4 are located midway between Vl and V6, the QRS
complex would be expected to be nearly isoelectric in one of these leads; i.e., the positive and
negative deflections will be about equal.
Sequence
Depolarization occurs in the sinoatrial (SA) node. Current travels through internodal tracts of
the atria to the atrioventricular (AV) node. Then through Bundle of His, which divides into
right and left bundle branches. Left bundle branch divides into left anterior and posterior
fascicles.
ECG Electrodes(1)
Two arrangements, bipolar and unipolar leads.
1. Bipolar Lead:
One in which the electrical activity at one electrode is compared with that of another. By
convention, a positive electrode is one in which the ECG records a positive (upward)
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deflection when the electrical impulse flows toward it and a negative (downward) deflection
when it flows away from it.
2. Unipolar Lead:
One in which the electrical potential at an exploring electrode is compared to a reference
point that averages electrical activity, rather than to that of another electrode. This single
electrode, termed the exploring electrode, is the positive electrode.
Limb Leads:
I, II, III, aVR, aVL, aVF explore the electrical activity in the heart in a frontal plane; i.e., the
orientation of the heart seen when looking directly at the anterior chest.
Standard Limb Leads:
I, II, III; bipolar, form a set of axes 60° apart
Lead I:
Composed of negative electrode on the right arm and positive electrode on the left arm.
Lead II:
Composed of negative electrode on the right arm and positive electrode on the left leg.
Lead III:
Composed of negative electrode on the left arm and positive electrode on the left leg.
Augmented Voltage Leads:
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aVR, aVL aVF; unipolar ; form a set of axes 60° apart but are rotated 30° from the axes of
the standard limb leads.
aVR: Exploring electrode located at the right shoulder.
aVL: Exploring electrode located at the left shoulder.
aVF: Exploring electrode located at the left foot.
Reference Point for Augmented Leads:
The opposing standard limb lead; i.e., that standard limb lead whose axis is perpendicular to
the particular augmented lead.
Chest Leads:
Vl, V2, V3, V4, V5, V6, explore the electrical activity of the heart in the horizontal plane;
i.e., as if looking down on a cross section of the body at the level of the heart. These are
exploring leads.
Reference Point for Chest Leads:
The point obtained by connecting the left arm, right arm, and left leg electrodes together.
Vl: Positioned in the 4th intercostal space just to the right of the sternum.
V2: Positioned in the 4th intercostal space just to the left of the sternum.
V3: Positioned halfway between V2 and V4.
V4: Positioned at the 5th intercostal space in the mid-clavicular line.
9
V5: Positioned in the anterior axillary line at the same level as V4.
V6: Positioned in the mid axillary line at the same level as V4 and V5.
Vl and V2*: Monitor electrical activity of the heart from the anterior aspect, septum, and
right ventricle.
V3 and V4*: Monitor electrical activity of the heart from the anterior aspect.
V5 and V6*: Monitor electrical activity of the heart from the left ventricle and lateral aspect.
Rhythms(8)
The normal rhythms of the heart known as Sinus Rhythm.
The criteria for a Normal Sinus Rhythm is:
P-wave before each QRS with an interval of 0.12 to 0.20 seconds in duration. A QRS width of 0.04 to 0.12 seconds
Q-T interval of less the 0.40 seconds.
The rate for a normal sinus rhythm is 60 to 100 beats a minute
If the rate is below 60 beats a minute but the rest is the same it is a Sinus Bradycardia.
If the rate is between 100 to 150 beats a minute with the same intervals it is a Sinus
Tachycardia.
When the pattern becomes irregular with normal intervals it is a Sinus Arrhythmia
10
Normal ECG(1)
Pulse rate lies between 60 and 100 beats/minute
Rhythm is regular except for minor variations with respiration.
P-R interval is the time required for completion of aerial depolarization; conduction
through the AV note, bundle of His, and bundle branches; and arrival at the
ventricular myocardial cells. The normal P-R interval is 0 12 to 0.20 seconds.
The QRS interval represents the time required for ventricular cells to depolarize. The
normal duration is 0.06 to 0.10 seconds.
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The Q-T interval is the time required for depolarization and repolarization of the
ventricles.
The time required is proportional to the heart rate. The faster the heart rate, the faster the
repolarization, and therefore the shorter the Q-T interval. With slow heart rates, the Q-T
interval is longer. The Q-T interval represents about 40% of the total time between the QRS
complexes (the R-R interval). In most cases, the Q-T interval lasts between 0.34 and 0.42
seconds.
Dimensions of Grids on ECG Paper:
Horizontal axis represents time. Large blocks are 0.2 seconds in duration, while small blocks
are 0.04 seconds in duration. Vertical axis represents voltage. Large blocks are 5mm, while
small blocks represent 1mm.
Indication(6)
An ECG is used to measure:
Any damage to the heart
How fast your heart is beating and whether it is beating normally
The effects of drugs or devices used to control the heart (such as a pacemaker)
The size and position of your heart chambers
An ECG is a very useful tool for determining whether a person has heart disease. Your doctor
may order this test if you have chest pain or palpitations.
12
An ECG may be included as part of a routine examination in patients over age 40.
Caution(6)
Make sure your health care provider knows about all the medications you are taking, as some
can interfere with test results.
Exercising or drinking cold water immediately before an ECG may cause false results.
Risks(6)
There are no risks. No electricity is sent through the body, so there is no risk of shock.
Preparation(6)
You will be asked to remove your clothes, then you will be asked to lie down. The health care
provider will clean several areas on your arms, legs, and chest, and then attach small patches
called electrodes to the areas. It may be necessary to shave or clip some hair so the electrodes
stick to the skin.
The electrodes may feel cold when first applied. In rare cases, some people may develop a
rash or irritation where the patches were placed.
The number of patches used may vary.
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You usually need to remain still, and you may be asked to hold your breath for short periods
during the procedure. It is important to be relaxed and relatively warm during ECG recording.
Any movement, including muscle tremors such as shivering, can alter the results.
The electrodes are connected by wires to a machine that converts the electrical signals from
the heart into wavy lines, which are printed on paper and reviewed by the doctor.
Sometimes this test is done while you are exercising or under minimal stress to monitor
changes in the heart. This type of ECG is often called a stress test.
Results on ECG(6)
- Normal Results
Heart rate: 50 to 100 beats per minute
Heart rhythm: consistent and even
- Abnormal Results
Abnormal ECG results may be a sign of
Abnormal heart rhythms (arrhythmias)
Cardiac muscle defect
Congenital heart defect
Coronary artery disease
Ectopic heartbeat
14
Enlargement of the heart
Faster-than-normal heart rate (tachycardia)
Heart valve disease
Inflammation of the heart (myocarditis)
Changes in the amount of electrolytes (chemicals in the blood)
Past heart attack
Present or impending heart attack
Slower-than-normal heart rate (bradycardia)
Additional conditions under which the test may be performed include the following:
Alcoholic cardiomyopathy
Anorexia nervosa
Aortic dissection
Aortic insufficiency
Aortic stenosis
Atrial fibrillation/flutter
Atrial myxoma
Atrial septal defect
Cardiac tamponade
Coarctation of the aorta
Complicated alcohol abstinence
(delirium tremens)
Coronary artery spasm
Digitalis toxicity
Dilated cardiomyopathy
Drug-induced lupus erythematosus
Familial periodic paralysis
Guillain-Barre
15
Heart failure
Hyperkalemia
Hypertensive heart disease
Hypertrophic cardiomyopathy
Hypoparathyroidism
Idiopathic cardiomyopathy
Infective endocarditis
Insomnia
Ischemic cardiomyopathy
Left-sided heart failure
Lyme disease
Mitral regurgitation; acute
Mitral regurgitation; chronic
Mitral stenosis
Mitral valve prolapse
Multifocal atrial tachycardia
Narcolepsy
Obstructive sleep apnea
Paroxysmal supraventricular
tachycardia
Patent ductus arteriosus
Pericarditis
o Bacterial pericarditis
o Constrictive pericarditis
o Post-MI pericarditis
Peripartum cardiomyopathy
Primary amyloid
Primary hyperaldosteronism
Primary hyperparathyroidism
Primary pulmonary hypertension
Pulmonary embolus
Pulmonary valve stenosis
Restrictive cardiomyopathy
Right-sided heart failure
Sick sinus syndrome
Stable angina
Stroke 16
Systemic lupus erythematosus
Tetralogy of Fallot
Thyrotoxic periodic paralysis
Transient ischemic attack (TIA)
Transposition of the great vessels
Tricuspid regurgitation
Type 1 diabetes
Type 2 diabetes
Unstable angina
Ventricular septal defect
Ventricular tachycardia
Wolff-Parkinson-White syndrome
II. ECHOCARDIOGRAPHY
Definition(10,11)
Echocardiography is a diagnostic test which uses ultrasound waves to create a moving picture
of the heart, to make images of the heart chambers, valves and surrounding structures. It can
measure cardiac output and is a sensitive test for inflammation around the heart (pericarditis).
It can also be used to detect abnormal anatomy or infections of the heart valves. The picture
is much more detailed than a plain x-ray image and involves no radiation exposure.
Echo can be used as part of a stress test and with an electrocardiogram (ECG) to help your
doctor learn more about your heart.
Types(13)
The different types of echocardiograms are:
17
Transthoracic echocardiogram (TTE). This is the most common type. Views of the
heart are obtained by moving the transducer to different locations on your chest or
abdominal wall.
Stress echocardiogram. During this test, an echocardiogram is done both before and
after your heart is stressed either by having you exercise or by injecting a medicine
that makes your heart beat harder and faster. A stress echocardiogram is usually done
to find out if you might have decreased blood flow to your heart (coronary artery
disease, or CAD).
Doppler echocardiogram. This test is used to look at how blood flows through the
heart chambers, heart valves, and blood vessels. The movement of the blood reflects
sound waves to a transducer. The ultrasound computer then measures the direction
and speed of the blood flowing through your heart and blood vessels. Doppler
measurements may be displayed in black and white or in color.
Transesophageal echocardiogram (TEE). For this test, the probe is passed down the
esophagus instead of being moved over the outside of the chest wall. TEE shows
clearer pictures of your heart, because the probe is located closer to the heart and
because the lungs and bones of the chest wall do not block the sound waves produced
by the probe. A sedative and an anesthetic applied to the throat are used to make you
comfortable during this test.
Indication(11)
This test is performed to evaluate the valves and chambers of the heart in a noninvasive way. The echocardiogram allows doctors to diagnose, evaluate, and monitor:
18
Heart murmurs Abnormal heart valves
The pumping function of the heart for people with heart failure
Damage to the heart muscle in patients who have had heart attacks
Infection in the sac around the heart (pericarditis)
Infection on or around the heart valves (infectious endocarditis)
The source of a blood clot or emboli after a stroke or TIA
Congenital heart disease
Atrial fibrillation
Pulmonary hypertension
Risks(11)
There are no known risks associated with this test.
Preparation(11)
You will be asked to remove your clothes from the waist up and lie on an examination table
on your back. Electrodes will be placed on your chest to allow for an echo to be done. A gel
will be spread on your chest and then the transducer will be applied. You will feel a slight
pressure on your chest from the transducer. You may be asked to breathe in a certain way or
to roll over onto your left side.
A trained sonographer performs the test, then your heart doctor interprets the results. An
instrument called a transducer that transmits high-frequency sound waves is placed on your
ribs near the breast bone and directed toward the heart.
19
Additional images will be taken underneath and slightly to the left of your nipple (at the apex
of your heart). The transducer picks up the echoes of the sound waves and transmits them as
electrical impulses. The echocardiography machine converts these impulses into moving
pictures of the heart. The Doppler probe records the motion of the blood through the heart.
An echocardiogram allows doctors to see the heart beating, and to see many of the structures
of the heart. Occasionally, your lungs, ribs, or body tissue may prevent the sound waves and
echoes from providing a clear picture of heart function. If so, the sonographer may inject a
small amount of liquid (contrast) through an IV to better see the inside of the heart.
Very rarely, more invasive testing using special echocardiography probes may be necessary.
Your health care provider may choose to perform a TEE:
If the regular or transthoracic echocardiogram is unclear due to a barrel chest, lung
disease, or obesity
If a much clearer picture is needed of a certain area
With TEE, the back of your throat is numbed and a scope is inserted down your throat. On
the end of the scope is an ultrasonic device that an experienced technician will guide down to
the lower part of the esophagus. It is used to obtain a more clear two-dimensional
echocardiogram of your heart.
Results on Echocardiography(11)
- Normal Results
20
A normal echocardiogram reveals normal heart valves and chambers and normal heart wall
movement.
- Abnormal Results
An abnormal echocardiogram can mean many things. Some abnormalities are very minor and
do not pose significant risks. Other abnormalities are signs of very serious heart disease that
will require further evaluation by a specialist. Therefore, it is very important to discuss the
results of your echocardiogram in depth with your health care provider.
Abnormal results may indicate heart valve disease, cardiomyopathy, pericardial effusion, or other heart abnormalities. This test may also be performed for the following conditions:
Alcoholic cardiomyopathy Aortic dissection
Aortic insufficiency
Aortic stenosis
Arrhythmias
Arterial embolism
Atrial fibrillation/flutter
Atrial myxoma
Atrial septal defect
Cardiac tamponade
Cardiomyopathy
Coarctation of the aorta
Heart attack
Heart failure
Hypertensive heart disease
Mitral regurgitation; acute
Mitral regurgitation; chronic
Mitral stenosis
Mitral valve prolapse
Patent ductus arteriosus
Pericarditis; bacterial
Pericarditis; constrictive
Pericarditis; post-MI
Peripartum cardiomyopathy
Primary amyloidosis
Pulmonary arterial hypertension
Pulmonary valve stenosis
Restrictive cardiomyopathy
Right-sided heart failure
Secondary systemic amyloidosis
Senile cardiac amyloidosis
Stroke
Tetralogy of Fallot
Transient ischemic attack (TIA)
21
Transposition of the great vessels
Tricuspid regurgitation
Ventricular septal defect
22
Conclusion
Both electrocardiography and echocardiography are very useful to help the doctors diagnose
problems on their patients’ heart. Its use for each indication. Altough both of them already
passed many year but those two are still very often used to help to diagnose besides interview,
physical examination and the, laboratory finding.
References
1. R. Richter, MD. Basic Electrocardiography. Available at :
http://www.sh.lsuhsc.edu/fammed/OutpatientManual/BasicECG.htm . Accessed July 3,
2010.
2. Dubin, Dale: Rapid Interpretation of EKG’s, Third Edition. Cover Publishing Company,
Tampa, FL, 1981.
3. Grauer, Ken: 12 Lead EKGs A “Pocket Brain” for Easy Interpretation. KG/EKG Press,
Gainsville, FL.
4. Marriott, Henry JL: Practical Electrocardiography, Sixth Edition. Waverly Press, Inc,
Baltimore, MD. 1981.
5. Milhorn, Jr., HT: Electrocardiology for the Family Physician: Parts 1-5. Family Practice
Recertification. Vol 5, No’s 2,3,4,5 & 6. Months Feb, Mar, Apr, May & June,
respectively, 1983.
6. Basic ECG. Available at www.nlm.nih.gov/medlineplus/ency/article/003868.htm .
Accessed July 11, 2010.
7. Ganz L, Curtiss E. Electrocardiography. In: Goldman L, Ausiello D, eds. Cecil Medicine.
23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 52.
8. Aaron Segel. Sinus Rhythms. Available at
http://www.drsegal.com/medstud/ecg/Sinus.htm . Accessed July 11, 2010.
9. Definition of Echocardiography. Available at
http://www.emedicinehealth.com/script/main/art.asp?articlekey=3182 . Accessed July 11,
2010.
10. Echocardiography. Available at
http://www.nhlbi.nih.gov/health/dci/Diseases/echo/echo_whatis.html . Accessed July 11,
2010.
11. Echocardiography. Available at
http://www.nlm.nih.gov/medlineplus/ency/article/003869.htm . Accessed July 11, 2010.
12. Connolly HM, Oh JK. Echocardiography. In: Libby P, Bonow RO, Mann DL, Zipes DP,
eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed.
Philadelphia, Pa: Saunders Elsevier;2007: chap 14.
13. Echocardiogram. Available at http://www.webmd.com/heart-disease/echocardiogram .
Accessed July 11, 2010.