ECG" redirects here. For other uses, see ECG (disambiguation).Not to be confused with echocardiogram, electromyogram, electroencephalogram, or EEG.

12 Lead ECG of a 26-year-old male.

Image showing a patient connected to the 10 electrodes necessary for a 12-lead ECG

Electrocardiography (ECG, or EKG [from the German Elektrokardiogramm]) is a transthoracic interpretation of the electrical activity of the heart over time captured and externally recorded by skin electrodes.[1] It is a noninvasive recording produced by an electrocardiographic device. The etymology of the word is derived from the Greek electro, because it is related to electrical activity, cardio, Greek for heart, and graph, a Greek root meaning "to write". In English speaking countries, medical professionals often write EKG (the abbreviation for the German word elektrokardiogramm) in order to avoid confusion with EEG.[citation needed]

The ECG works mostly by detecting and amplifying the tiny electrical changes on the skin that are caused when the heart muscle "depolarises" during each heart beat. At rest, each heart muscle cell has a charge across its outer wall, or cell membrane. Reducing this charge towards zero is called de-polarisation, which activates the mechanisms in the cell that cause it to contract. During each heartbeat a healthy heart will have an orderly progression of a wave of depolarisation that is triggered by the cells in the sinoatrial node, spreads out through the atrium, passes through "intrinsic conduction pathways" and then spreads all over the ventricles. This is detected as tiny rises and falls in the voltage between two electrodes placed either side of the

heart which is displayed as a wavy line either on a screen or on paper. This display indicates the overall rhythm of the heart and weaknesses in different parts of the heart muscle.

Usually more than 2 electrodes are used and they can be combined into a number of pairs. (For example: Left arm (LA),right arm (RA) and left leg (LL) electrodes form the pairs: LA+RA, LA+LL, RA+LL) The output from each pair is known as a lead. Each lead is said to look at the heart from a different angle. Different types of ECGs can be referred to by the number of leads that are recorded, for example 3-lead, 5-lead or 12-lead ECGs (sometimes simply "a 12-lead"). A 12-lead ECG is one in which 12 different electrical signals are recorded at approximately the same time and will often be used as a one-off recording of an ECG, typically printed out as a paper copy. 3- and 5-lead ECGs tend to be monitored continuously and viewed only on the screen of an appropriate monitoring device, for example during an operation or whilst being transported in an ambulance. There may, or may not be any permanent record of a 3- or 5-lead ECG depending on the equipment used.

It is the best way to measure and diagnose abnormal rhythms of the heart,[2] particularly abnormal rhythms caused by damage to the conductive tissue that carries electrical signals, or abnormal rhythms caused by electrolyte imbalances.[3] In a myocardial infarction (MI), the ECG can identify if the heart muscle has been damaged in specific areas, though not all areas of the heart are covered.[4] The ECG cannot reliably measure the pumping ability of the heart, for which ultrasound-based (echocardiography) or nuclear medicine tests are used. It is possible to be in cardiac arrest with a normal ECG signal (a condition known as pulseless electrical activity).

Contents

[hide]

1 History 2 ECG graph paper

o 2.1 Layout 3 Leads

o 3.1 Placement of electrodes 3.1.1 Additional electrodes

o 3.2 Limb leads o 3.3 Unipolar vs. bipolar leads o 3.4 Augmented limb leads o 3.5 Precordial leads

4 Waves and intervals 5 Vectors and views

o 5.1 Axis o 5.2 Clinical lead groups

6 Filter selection 7 Indications 8 Some pathological entities which can be seen on the ECG

o 8.1 Electrocardiogram heterogeneity 9 See also

10 References 11 External links

[edit] History

Alexander Muirhead is reported to have attached wires to a feverish patient's wrist to obtain a record of the patient's heartbeat while studying for his Doctor of Science (in electricity) in 1872 at St Bartholomew's Hospital.[5] This activity was directly recorded and visualized using a Lippmann capillary electrometer by the British physiologist John Burdon Sanderson.[6] The first to systematically approach the heart from an electrical point-of-view was Augustus Waller, working in St Mary's Hospital in Paddington, London.[7] His electrocardiograph machine consisted of a Lippmann capillary electrometer fixed to a projector. The trace from the heartbeat was projected onto a photographic plate which was itself fixed to a toy train. This allowed a heartbeat to be recorded in real time. In 1911 he still saw little clinical application for his work.

Einthoven's ECG device

An initial breakthrough came when Willem Einthoven, working in Leiden, Netherlands, used the string galvanometer that he invented in 1903.[8] This device was much more sensitive than both the capillary electrometer that Waller used and the string galvanometer that had been invented separately in 1897 by the French engineer Clément Ader.[9] Rather than using today's self-adhesive electrodes Einthoven's subjects would immerse each of their limbs into containers of salt solutions from which the ECG was recorded.

Einthoven assigned the letters P, Q, R, S and T to the various deflections, and described the electrocardiographic features of a number of cardiovascular disorders. In 1924, he was awarded the Nobel Prize in Medicine for his discovery.[10]

Though the basic principles of that era are still in use today, there have been many advances in electrocardiography over the years. The instrumentation, for example, has evolved from a cumbersome laboratory apparatus to compact electronic systems that often include computerized interpretation of the electrocardiogram.[11]

[edit] ECG graph paper

One second of ECG graph paper

The output of an ECG recorder is a graph (or sometimes several graphs, representing each of the leads) with time represented on the x-axis and voltage represented on the y-axis. A dedicated ECG machine would usually print onto graph paper which has a background pattern of 1mm squares (often in red or green), with bold divisions every 5mm in both vertical and horizontal directions. It is possible to change the output of most ECG devices but it is standard to represent each mV on the y axis as 1 cm and each second as 25mm on the x-axis (that is a paper speed of 25mm/s). Faster paper speeds can be used - for example to resolve finer detail in the ECG. At a paper speed of 25 mm/s, one small block of ECG paper translates into 40 ms. Five small blocks make up one large block, which translates into 200 ms. Hence, there are five large blocks per second. A calibration signal may be included with a record. A standard signal of 1 mV must move the stylus vertically 1 cm, that is two large squares on ECG paper.

[edit] Layout

By definition a 12-lead ECG will show a short segment of the recording of each of the 12-leads. This is often arranged in a grid of 4 columns by three rows, the first columns being the limb leads (I,II and III), the second column the augmented limb leads (aVR, aVL and aVF) and the last two columns being the chest leads (V1-V6). It is usually possible to change this layout so it is vital to check the labels to see which lead is represented. Each column will usually record the same moment in time for the three leads and then the recording will switch to the next column which will record the heart beats after that point. It is possible for the heart rhythm to change between the columns of leads. Each of these segments is short, perhaps 1-3 heart beats only, depending on the heart rate and it can be difficult to analyse any heart rhythm that shows changes between heart beats. To help with the analysis it is common to print one or two "rhythm strips" as well. This will usually be lead II (which shows the electrical signal from the atrium, the P-wave, well) and shows the rhythm for the whole time the ECG was recorded (usually 5–6 seconds). The term "rhythm strip" may also refer to the whole printout from a continuous monitoring system which may show only one lead and is either initiated by a clinician or in response to an alarm or event.

[edit] Leads

The term "lead" in electrocardiography causes much confusion because it is used to refer to two different things. In accordance with common parlance the word lead may be used to refer to the electrical cable attaching the electrodes to the ECG recorder. As such it may be acceptable to refer to the "left arm lead" as the electrode (and its cable) that should be attached at or near the left arm. There are usually ten of these electrodes in a standard "12-lead" ECG.

Alternatively (and some would say properly, in the context of electrocardiography) the word lead may refer to the tracing of the voltage difference between two of the electrodes and is what is actually produced by the ECG recorder. Each will have a specific name. For example "Lead I" (lead one) is the voltage between the right arm electrode and the left arm electrode, whereas "Lead II" (lead two) is the voltage between the right limb and the feet. (This rapidly becomes more complex as one of the "electrodes" may in fact be a composite of the electrical signal from a combination of the other electrodes. (See later.) Twelve of this type of lead form a "12-lead" ECG

To cause additional confusion the term "limb leads" usually refers to the tracings from leads I, II and III rather than the electrodes attached to the limbs.

[edit] Placement of electrodes

Ten electrodes are used for a 12-lead ECG. The electrodes usually consist of a conducting gel, embedded in the middle of a self-adhesive pad onto which cables clip. Sometimes the gel also forms the adhesive.[12] They are labeled and placed on the patient's body as follows:[13][14]

Proper placement of the limb electrodes, color coded as recommended by the American Heart Association (a different colour scheme is used in Europe). Note that the limb electrodes can be far down on the limbs or close to the hips/shoulders, but they must be even (left vs right).[15]

12 leadsElectrode

label (in the USA)

Electrode placement

RA On the right arm, avoiding bony prominences.

LA In the same location that RA was placed, but on the left arm this time.

RL On the right leg, avoiding bony prominences.

LL In the same location that RL was placed, but on the left leg this time.

V1In the fourth intercostal space (between ribs 4 & 5) just to the right of the sternum (breastbone).

V2 In the fourth intercostal space (between ribs 4 & 5) just to the left of the sternum.

V3 Between leads V2 and V4.

V4In the fifth intercostal space (between ribs 5 & 6) in the mid-clavicular line (the imaginary line that extends down from the midpoint of the clavicle (collarbone)).

V5

Horizontally even with V4, but in the anterior axillary line. (The anterior axillary line is the imaginary line that runs down from the point midway between the middle of the clavicle and the lateral end of the clavicle; the lateral end of the collarbone is the end closer to the arm.)

V6Horizontally even with V4 and V5 in the midaxillary line. (The midaxillary line is the imaginary line that extends down from the middle of the patient's armpit.)

[edit] Additional electrodes

The classical 12-lead ECG can be extended in a number of ways in an attempt to improve its sensitivity in detecting myocardial infarction involving territories not normally "seen" well. This includes an rV4 lead which uses the equivalent landmarks to the V4 but on the right side of the chest wall and extending the chest leads onto the back with a V7, V8 and V9.

[edit] Limb leads

In both the 5- and 12-lead configuration, leads I, II and III are called limb leads. The electrodes that form these signals are located on the limbs—one on each arm and one on the left leg.[16][17][18] The limb leads form the points of what is known as Einthoven's triangle.[19]

Lead I is the voltage between the (positive) left arm (LA) electrode and right arm (RA) electrode:

I = LA − RA.

Lead II is the voltage between the (positive) left leg (LL) electrode and the right arm (RA) electrode:

II = LL − RA.

Lead III is the voltage between the (positive) left leg (LL) electrode and the left arm (LA) electrode:

III = LL − LA.

Simplified electrocardiograph sensors designed for teaching purposes at e.g. high school level are generally limited to three arm electrodes serving similar purposes. [20]

[edit] Unipolar vs. bipolar leads

There are two types of leads: unipolar and bipolar. Bipolar leads have one positive and one negative pole.[21] In a 12-lead ECG, the limb leads (I, II and III) are bipolar leads. Unipolar leads also have two poles, as a voltage is measured; however, the negative pole is a composite pole (Wilson's central terminal) made up of signals from lots of other electrodes.[22] In a 12-lead ECG, all leads besides the limb leads are unipolar (aVR, aVL, aVF, V1, V2, V3, V4, V5, and V6).

Wilson's central terminal VW is produced by connecting the electrodes, RA; LA; and LL, together, via a simple resistive network, to give an average potential across the body, which approximates the potential at infinity (i.e. zero):

[edit] Augmented limb leads

Leads aVR, aVL, and aVF are augmented limb leads (after their inventor Dr. Emanuel Goldberger known collectively as the Goldberger's leads). They are derived from the same three electrodes as leads I, II, and III. However, they view the heart from different angles (or vectors) because the negative electrode for these leads is a modification of Wilson's central terminal. This zeroes out the negative electrode and allows the positive electrode to become the "exploring electrode". This is possible because Einthoven's Law states that I + (−II) + III = 0. The equation can also be written I + III = II. It is written this way (instead of I − II + III = 0) because Einthoven reversed the polarity of lead II in Einthoven's triangle, possibly because he liked to view upright QRS complexes. Wilson's central terminal paved the way for the development of the augmented limb leads aVR, aVL, aVF and the precordial leads V1, V2, V3, V4, V5 and V6.

Lead augmented vector right (aVR) has the positive electrode (white) on the right arm. The negative electrode is a combination of the left arm (black) electrode and the left leg (red) electrode, which "augments" the signal strength of the positive electrode on the right arm:

Lead augmented vector left (aVL) has the positive (black) electrode on the left arm. The negative electrode is a combination of the right arm (white) electrode and the left leg (red) electrode, which "augments" the signal strength of the positive electrode on the left arm:

Lead augmented vector foot (aVF) has the positive (red) electrode on the left leg. The negative electrode is a combination of the right arm (white) electrode and the left arm (black) electrode, which "augments" the signal of the positive electrode on the left leg:

The augmented limb leads aVR, aVL, and aVF are amplified in this way because the signal is too small to be useful when the negative electrode is Wilson's central terminal. Together with leads I, II, and III, augmented limb leads aVR, aVL, and aVF form the basis of the hexaxial reference system, which is used to calculate the heart's electrical axis in the frontal plane. The aVR, aVL, and aVF leads can also be represented using the I and II limb leads:

[edit] Precordial leads

The electrodes for the precordial leads (V1, V2, V3, V4, V5 and V6) are placed directly on the chest. Because of their close proximity to the heart, they do not require augmentation. Wilson's central terminal is used for the negative electrode, and these leads are considered to be unipolar (recall that Wilson's central terminal is the average of the three limb leads. This approximates common, or average, potential over the body). The precordial leads view the heart's electrical activity in the so-called horizontal plane. The heart's electrical axis in the horizontal plane is referred to as the Z axis.

[edit] Waves and intervals

Schematic representation of normal ECG

Animation of a normal ECG wave.

Detail of the QRS complex, showing ventricular activation time (VAT) and amplitude.

A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave, a QRS complex, a T wave, and a U wave which is normally visible in 50 to 75% of ECGs.[23] The baseline voltage of the electrocardiogram is known as the isoelectric line. Typically the isoelectric line is measured as the portion of the tracing following the T wave and preceding the next P wave.

Feature Description DurationRR interval

The interval between an R wave and the next R wave is the inverse of the heart rate. Normal resting heart rate is between 50 and 100 bpm

0.6 to 1.2s

P waveDuring normal atrial depolarization, the main electrical vector is directed from the SA node towards the AV node, and spreads from the right atrium to the left atrium. This turns into the P wave on the ECG.

80ms

PR interval

The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. The PR interval reflects the time the electrical impulse takes to travel from the sinus node through the AV node and entering the ventricles. The PR interval is therefore a good estimate of AV node function.

120 to 200ms

PR segment

The PR segment connects the P wave and the QRS complex. This coincides with the electrical conduction from the AV node to the bundle of His to the bundle branches and then to the Purkinje Fibers. This electrical activity does not produce a contraction directly and is merely traveling down towards the ventricles and this shows up flat on the

50 to 120ms

ECG. The PR interval is more clinically relevant.

QRS complex

The QRS complex reflects the rapid depolarization of the right and left ventricles. They have a large muscle mass compared to the atria and so the QRS complex usually has a much larger amplitude than the P-wave.

80 to 120ms

J-pointThe point at which the QRS complex finishes and the ST segment begins. Used to measure the degree of ST elevation or depression present.

N/A

ST segment

The ST segment connects the QRS complex and the T wave. The ST segment represents the period when the ventricles are depolarized. It is isoelectric.

80 to 120ms

T wave

The T wave represents the repolarization (or recovery) of the ventricles. The interval from the beginning of the QRS complex to the apex of the T wave is referred to as the absolute refractory period. The last half of the T wave is referred to as the relative refractory period (or vulnerable period).

160ms

ST interval

The ST interval is measured from the J point to the end of the T wave. 320ms

QT interval

The QT interval is measured from the beginning of the QRS complex to the end of the T wave. A prolonged QT interval is a risk factor for ventricular tachyarrhythmias and sudden death. It varies with heart rate and for clinical relevance requires a correction for this, giving the QTc.

300 to 430ms[citation

needed]

U waveThe U wave is not always seen. It is typically low amplitude, and, by definition, follows the T wave.

J waveThe J wave, elevated J-Point or Osborn Wave appears as a late delta wave following the QRS or as a small secondary R wave . It is considered pathognomic of hypothermia or hypocalcemia.[24]

There were originally four deflections, but after the mathematical correction for artifacts introduced by early amplifiers, five deflections were discovered. Einthoven chose the letters P, Q, R, S, and T to identify the tracing which was superimposed over the uncorrected labeled A, B, C, and D.[25]

[edit] Vectors and views

Graphic showing the relationship between positive electrodes, depolarization wavefronts (or mean electrical vectors), and complexes displayed on the ECG.

Interpretation of the ECG relies on the idea that different leads (by which we mean the ECG leads I,II,III, aVR, aVL, aVF and the chest leads) "view" the heart from different angles. This has two benefits. Firstly, leads which are showing problems (for example ST segment elevation) can be used to infer which region of the heart is affected. Secondly, the overall direction of travel of the wave of depolarisation can also be inferred which can reveal other problems. This is termed the cardiac axis . Determination of the cardiac axis relies on the concept of a vector which describes the motion of the depolarisation wave. This vector can then be described in terms of its components in relation to the direction of the lead considered. One component will be in the direction of the lead and this will be revealed in the behaviour of the QRS complex and one component will be at 90 degrees to this (which will not). Any net positive deflection of the QRS complex (i.e. height of the R-wave minus depth of the S-wave) suggests that the wave of depolarisation is spreading through the heart in a direction that has some component (of the vector) in the same direction as the lead in question.

[edit] Axis

Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane.

The heart's electrical axis refers to the general direction of the heart's depolarization wavefront (or mean electrical vector) in the frontal plane. With a healthy conducting system the cardiac axis is related to where the major muscle bulk of the heart lies. Normally this is the left ventricle with some contribution from the right ventricle. It is usually oriented in a right shoulder to left leg direction, which corresponds to the left inferior quadrant of the hexaxial reference system, although −30° to +90° is considered to be normal. If the left ventricle increases its activity or

bulk then there is said to be "left axis deviation" as the axis swings round to the left beyond -30°, alternatively in conditions where the right ventricle is strained or hypertrophied then the axis swings round beyond +90° and "right axis deviation" is said to exist. Disorders of the conduction system of the heart can disturb the electrical axis without necessarily reflecting changes in muscle bulk.

Normal−30° to 90°

Normal Normal

Left axis deviation

−30° to −90°

May indicate left anterior fascicular block or Q waves from inferior MI.

Left axis deviation is considered normal in pregnant women and those with emphysema.

Right axis deviation

+90° to +180°

May indicate left posterior fascicular block, Q waves from high lateral MI, or a right ventricular strain pattern.

Right deviation is considered normal in children and is a standard effect of dextrocardia.

Extreme right axis deviation

+180° to −90°

Is rare, and considered an 'electrical no-man's land'.

In the setting of right bundle branch block, right or left axis deviation may indicate bifascicular block.

[edit] Clinical lead groups

There are twelve leads in total, each recording the electrical activity of the heart from a different perspective, which also correlate to different anatomical areas of the heart for the purpose of identifying acute coronary ischemia or injury. Two leads that look at neighbouring anatomical areas of the heart are said to be contiguous (see color coded chart). The relevance of this is in determining whether an abnormality on the ECG is likely to represent true disease or a spurious finding.

Diagram showing the contiguous leads in the same color

CategoryColor on

chartLeads Activity

Inferior leads

YellowLeads II, III and aVF

Look at electrical activity from the vantage point of the inferior surface (diaphragmatic surface of heart).

Lateral leads

Green I, aVL, V5

and V6

Look at the electrical activity from the vantage point of the lateral wall of left ventricle.

The positive electrode for leads I and aVL should be located distally on the left arm and because of which, leads I and aVL are sometimes referred to as the high lateral leads.

Because the positive electrodes for leads V5 and V6 are on the patient's chest, they are sometimes referred to as the low lateral leads.

Septal leads

Orange V1 and V2Look at electrical activity from the vantage point of the septal wall of the ventricles (interventricular septum).

Anterior leads

Blue V3 and V4Look at electrical activity from the vantage point of the anterior surface of the heart (sternocostal surface of heart).

In addition, any two precordial leads that are next to one another are considered to be contiguous. For example, even though V4 is an anterior lead and V5 is a lateral lead, they are contiguous because they are next to one another.

Lead aVR offers no specific view of the left ventricle. Rather, it views the inside of the endocardial wall to the surface of the right atrium, from its perspective on the right shoulder.

[edit] Filter selection

Modern ECG monitors offer multiple filters for signal processing. The most common settings are monitor mode and diagnostic mode. In monitor mode, the low frequency filter (also called the high-pass filter because signals above the threshold are allowed to pass) is set at either 0.5 Hz or 1 Hz and the high frequency filter (also called the low-pass filter because signals below the threshold are allowed to pass) is set at 40 Hz. This limits artifact for routine cardiac rhythm monitoring. The high-pass filter helps reduce wandering baseline and the low-pass filter helps reduce 50 or 60 Hz power line noise (the power line network frequency differs between 50 and 60 Hz in different countries). In diagnostic mode, the high-pass filter is set at 0.05 Hz, which allows accurate ST segments to be recorded. The low-pass filter is set to 40, 100, or 150 Hz. Consequently, the monitor mode ECG display is more filtered than diagnostic mode, because its passband is narrower.[26]

Electrocardiogram

An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG translates the heart's electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves. See a picture of the EKG components and intervals .

The heart is a muscular pump made up of four chambers . The two upper chambers are called atria, and the two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract and pump blood through the heart to the lungs and the rest of the body. See a picture of the heart and its electrical system .

Why It Is Done

An electrocardiogram (EKG or ECG) is done to:

Check the heart's electrical activity. Find the cause of unexplained chest pain, which could be caused by a heart attack,

inflammation of the sac surrounding the heart (pericarditis), or angina. Find the cause of symptoms of heart disease, such as shortness of breath, dizziness,

fainting, or rapid, irregular heartbeats (palpitations). Find out if the walls of the heart chambers are too thick (hypertrophied). Check how well medicines are working and whether they are causing side effects that

affect the heart. Check how well mechanical devices that are implanted in the heart, such as pacemakers,

are working to control a normal heartbeat. Check the health of the heart when other diseases or conditions are present, such as high

blood pressure, high cholesterol, cigarette smoking, diabetes, or a family history of early heart disease.

How To Prepare

Many medicines may change the results of this test. Be sure to tell your doctor about all the nonprescription and prescription medicines you take. If you take heart medicines, your doctor will tell you how to take your medicines before you have this test.

Remove all jewelry from your neck, arms, and wrists. Men are usually bare-chested during the test. Women may often wear a bra, T-shirtRemove all jewelry from your neck, arms, and wrists. Men are usually bare-chested during the test. Women may often wear a bra, T-shirt, or gown. If you are wearing stockings, you should take them off. You will be given a cloth or paper covering to use during the test.

Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will indicate. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?) .

How It Is Done

An electrocardiogram (EKG or ECG) is usually done by a health professional, and the resulting EKG is interpreted by a doctor, such as an internist, family medicine doctor, electrophysiologist, cardiologist, anesthesiologist, or surgeon.

You may receive an EKG as part of a physical examination at your health professional's office or during a series of tests at a hospital or clinic. EKG equipment is often portable, so the test can be done almost anywhere. If you are in the hospital, your heart may be continuously monitored by an EKG system; this process is called telemetry.

During an EKG:

You will lie on a bed or table. Areas on your arms, legs, and chest where small metal discs (electrodes) will be placed are cleaned and may be shaved to provide a clean, smooth surface to attach the electrode discs. A special EKG paste or small pads soaked in alcohol may be placed between the electrodes and your skin to improve conduction of the electrical impulses, but in many cases disposable electrodes are used that do not require paste or alcohol.

Several electrodes are attached to the skin on each arm and leg and on your chest. These are hooked to a machine that traces your heart activity onto a paper. If an older machine is used, the electrodes may be moved at different times during the test to measure your heart's electrical activity from different locations on your chest. After the procedure, the electrode paste is wiped off.

You will be asked to lie very still and breathe normally during the test. Sometimes you may be asked to hold your breath. You should not talk during the test.

How the Test is Performed

How the Test is Performed

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 patches stick to the skin. The number of patches used may vary.

The patches are connected by wires to a machine that turns the heart's electrical signals into wavy lines, which are often printed on paper. The test results are reviewed by the doctor.

You usually need to remain still during the procedure. The health care provider may also ask you to hold your breath for a few seconds as the test is being done. Any movement, including muscle tremors such as shivering, can alter the results. So it is important to be relaxed and relatively warm during an ECG recording.

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.

How to Prepare for the Test

How to Prepare for the Test

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.

How the Test Will Feel

How the Test Will Feel

An ECG is painless. No electricity is sent through the body. The electrodes may feel cold when first applied. In rare cases, some people may develop a rashrash or irritation where the patches were placed.

Why the Test is Performed

Why the Test is Performed

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 diseaseheart disease. Your doctor may order this test if you have chest painchest pain or palpitationspalpitations.

Normal Results

Normal Results

Heart rate: 60 to 100 beats per minute Heart rhythm: consistent and even

What Abnormal Results Mean

What Abnormal Results Mean

Abnormal ECG results may be a sign of

Abnormal heart rhythms (arrhythmiasarrhythmias) Cardiac muscle defect Congenital heart defect Coronary artery disease Coronary artery disease Ectopic heartbeat Ectopic heartbeat Enlargement of the heart Enlargement of the heart Faster-than-normal heart rate (tachycardiatachycardia) Heart valve disease Inflammation of the heart Inflammation of the heart (myocarditis) Changes in the amount of electrolyteselectrolytes (chemicals in the blood) Past heart attackheart 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 Anorexia nervosa Aortic dissection Aortic dissection Aortic insufficiency Aortic insufficiency Aortic stenosis Aortic stenosis Atrial fibrillation/flutter Atrial fibrillation/flutter Atrial myxoma Atrial septal defect Atrial septal defect Cardiac tamponade Cardiac tamponade Coarctation of the aorta Coarctation of the aorta Complicated alcohol abstinence (delirium tremens) Complicated alcohol abstinence

(delirium tremens)

Coronary artery spasm Coronary artery spasm Digitalis toxicity Digitalis toxicity Dilated cardiomyopathy Dilated cardiomyopathy Drug-induced lupus erythematosus Drug-induced lupus erythematosus Familial periodic paralysis Familial periodic paralysis Guillain-Barre Guillain-Barre Heart failure Heart failure Hyperkalemia Hyperkalemia Hypertensive heart disease Hypertensive heart disease Hypertrophic cardiomyopathy Hypertrophic cardiomyopathy Hypoparathyroidism Hypoparathyroidism Idiopathic cardiomyopathy Infective endocarditis Infective endocarditis Insomnia Insomnia Ischemic cardiomyopathy Ischemic cardiomyopathy Left-sided heart failure Lyme disease Lyme disease Mitral regurgitation; acute Mitral regurgitation; acute Mitral regurgitation; chronic Mitral regurgitation; chronic Mitral stenosis Mitral stenosis Mitral valve prolapse Mitral valve prolapse Multifocal atrial tachycardia Multifocal atrial tachycardia Narcolepsy Narcolepsy Obstructive sleep apnea Obstructive sleep apnea Paroxysmal supraventricular tachycardia Paroxysmal supraventricular tachycardia Patent ductus arteriosus Patent ductus arteriosus Pericarditis Pericarditis

o Bacterial pericarditis Bacterial pericarditis o Constrictive pericarditis Constrictive pericarditis o Post-MI pericarditis Post-MI pericarditis

Peripartum cardiomyopathy Peripartum cardiomyopathy Primary amyloid Primary amyloid Primary hyperaldosteronism Primary hyperaldosteronism Primary hyperparathyroidism Primary hyperparathyroidism Primary pulmonary hypertension Primary pulmonary hypertension Pulmonary embolus Pulmonary embolus Pulmonary valve stenosis Pulmonary valve stenosis Restrictive cardiomyopathy Restrictive cardiomyopathy Right-sided heart failure Sick sinus syndrome Sick sinus syndrome Stable angina Stable angina Stroke Stroke Systemic lupus erythematosus Systemic lupus erythematosus Tetralogy of Fallot Tetralogy of Fallot Thyrotoxic periodic paralysis Thyrotoxic periodic paralysis Transient ischemic attack (TIA) Transient ischemic attack (TIA)

Transposition of the great vessels Transposition of the great vessels Tricuspid regurgitation Tricuspid regurgitation Type 1 diabetes Type 2 diabetes Type 2 diabetes Unstable angina Unstable angina Ventricular septal defect Ventricular septal defect Ventricular tachycardia Ventricular tachycardia Wolff-Parkinson-White syndrome Wolff-Parkinson-White syndrome

Risks

Risks

There are no risks. No electricity is sent through the body, so there is no risk of shock.

Considerations

Considerations

The accuracy of the ECG depends on the condition being tested. A heart problem may not always show up on the ECG. Some heart conditions never produce any specific ECG changes.

If you have had a heart attack or have heart disease, you may need more than one ECG. Your doctor will tell you when you need the next one.

There is no reason for healthy people to have yearly ECG testing unless they have a family or personal history of specific heart diseases or other medical conditions that affect the heart.

Alternative Names

Alternative Names

ECG; EKG

What Is an Electrocardiogram?An electrocardiogram (e-lek-tro-KAR-de-o-gram), also called an EKG or ECG, is a simple, painless test that records the heart's electrical activity. To understand this test, it helps to understand how the heart works.

With each heartbeat, an electrical signal spreads from the top of the heart to the bottom. As it travels, the signal causes the heart to contract and pump blood. The process repeats with each new heartbeat.

The heart's electrical signals set the rhythm of the heartbeat. For more detailed information and animations, go to the Diseases and Conditions Index How the Heart Works article.

An EKG shows:

How fast your heart is beating Whether the rhythm of your heartbeat is steady or irregular The strength and timing of electrical signals as they pass through each part of your heart

Doctors use EKGs to detect and study many heart problems, such as heart attacks, arrhythmias (ah-RITH-me-ahs), and heart failure. The test's results also can suggest other disorders that affect heart function.

Other Names for an ElectrocardiogramAn electrocardiogram also is called an EKG or ECG. Sometimes the test is called a 12-lead EKG or 12-lead ECG. This is because the heart's electrical activity most often is recorded from 12 different places on the body at the same time.

Who Needs an Electrocardiogram?Your doctor may recommend an electrocardiogram (EKG) if you have signs or symptoms that suggest a heart problem. Examples of such signs and symptoms include:

Chest pain Heart pounding, racing, or fluttering, or the sense that your heart is beating unevenly Breathing problems Tiredness and weakness Unusual heart sounds when your doctor listens to your heartbeat

You may need to have more than one EKG so your doctor can diagnose certain heart conditions.

An EKG also may be done as part of a routine health exam. The test can screen for early heart disease that has no symptoms. Your doctor is more likely to look for early heart disease if your mother, father, brother, or sister had heart disease—especially early in life.

You may have an EKG so your doctor can check how well heart medicine or a medical device, such as a pacemaker, is working. The test also may be used for routine screening before major surgery.

Your doctor also may use EKG results to help plan your treatment for a heart condition.

What To Expect Before an ElectrocardiogramYou don't need to take any special steps before having an electrocardiogram (EKG). However, tell your doctor or his or her staff about the medicines you're taking. Some medicines can affect EKG results.

What To Expect During an ElectrocardiogramAn electrocardiogram (EKG) is painless and harmless. A nurse or technician will attach soft, sticky patches called electrodes to the skin of your chest, arms, and legs. The patches are about the size of a quarter.

Often, 12 patches are attached to your body. This helps detect your heart's electrical activity from many areas at the same time. The nurse may have to shave areas of your skin to help the patches stick.

After the patches are placed on your skin, you'll lie still on a table while the patches detect your heart's electrical signals. A machine will record these signals on graph paper or display them on a screen.

The entire test will take about 10 minutes.

EKG

The picture shows the standard setup for an EKG. In figure A, a heart rhythm recording shows the electrical pattern of a normal heartbeat. In figure B, a patient lies in a bed with EKG electrodes attached to his chest, upper arms, and legs. A nurse oversees the painless procedure.

Special Types of Electrocardiogram

The standard EKG described above, called a resting 12-lead EKG, only records seconds of heart activity at a time. It will show a heart problem only if the problem occurs during the test.

Many heart problems are present all the time, and a resting 12-lead EKG will detect them. But some heart problems, like those related to an irregular heartbeat, can come and go. They may occur only for a few minutes a day or only while you exercise.

Doctors use special EKGs, such as stress tests and Holter and event monitors, to help diagnose these kinds of problems.

Stress Test

Some heart problems are easier to diagnose when your heart is working hard and beating fast. During stress testing, you exercise to make your heart work hard and beat fast while an EKG is done. If you can't exercise, you'll be given medicine to make your heart work hard and beat fast.

For more information, go to the Diseases and Conditions Index (DCI) Stress Testing article.

Holter and Event Monitors

Holter and event monitors are small, portable devices. They record your heart's electrical activity while you do your normal daily activities. A Holter monitor records your heart's electrical activity for a full 24- or 48-hour period.

An event monitor records your heart's electrical activity only at certain times while you're wearing it. For many event monitors, you push a button to start the monitor when you feel symptoms. Other event monitors start automatically when they sense abnormal heart rhythms.

For more information, go to the DCI Holter and Event Monitors article.

What To Expect After an ElectrocardiogramAfter an electrocardiogram (EKG), the nurse or technician will remove the electrodes (soft patches) from your skin. You may develop a rash or redness where the EKG patches were attached. This mild rash often goes away without treatment.

You usually can go back to your normal daily routine after an EKG.

What Does an Electrocardiogram Show?Many heart problems change the heart's electrical activity in distinct ways. An electrocardiogram (EKG) can help detect these heart problems.

EKG recordings can help doctors diagnose heart attacks that are in progress or have happened in the past. This is especially true if doctors can compare a current EKG recording to an older one.

An EKG also can show:

Lack of blood flow to the heart muscle (coronary heart disease) A heartbeat that's too fast, too slow, or irregular (arrhythmia) A heart that doesn't pump forcefully enough (heart failure)

Heart muscle that's too thick or parts of the heart that are too big (cardiomyopathy) Birth defects in the heart (congenital heart defects) Problems with the heart valves (heart valve disease) Inflammation of the sac that surrounds the heart (pericarditis)

An EKG can reveal whether the heartbeat starts in the correct place in the heart. The test also shows how long it takes for electrical signals to travel through the heart. Delays in signal travel time may suggest heart block or long QT syndrome.

What Are the Risks of an Electrocardiogram?An electrocardiogram (EKG) has no serious risks. It's a harmless, painless test that detects the heart's electrical activity. EKGs don't give off electrical charges, such as shocks.

You may develop a mild rash where the electrodes (soft patches) were attached. This rash often goes away without treatment.

Key Points An electrocardiogram (EKG) is a simple, painless test that records the heart's electrical

activity. An EKG shows:

o How fast your heart is beating o Whether the rhythm of your heartbeat is steady or irregular o The strength and timing of electrical signals as they pass through each part of

your heart Doctors use EKGs to detect and study many heart problems, such as heart attacks,

arrhythmias, and heart failure. Your doctor may recommend an EKG if you have signs or symptoms that suggest a heart

problem. An EKG also may be done as part of a routine health exam, to check how medicine or a medical device is working, or for routine screening before major surgery. Your doctor may use EKG results to help plan your treatment for a heart condition.

You don't need to take any special steps before having an EKG. However, tell your doctor or his or her staff what medicines you're taking. Some medicines can affect EKG results.

During an EKG, soft, sticky patches called electrodes are attached to the skin of your chest, arms, and legs. You'll lie still on a table while the patches detect your heart's electrical signals. A machine will record these signals on graph paper or display them on a screen. The entire test will take about 10 minutes.

If you have a heart problem that isn't always present, you may need a special type of EKG, such as a stress test or Holter or event monitor.

You usually can go back to your normal daily routine after an EKG. Many heart problems change the heart's electrical activity in distinct ways. An EKG can

help detect these heart problems. Results from an EKG can suggest problems such as lack of blood flow to the heart muscle, problems with the heart's rhythm or pumping action, birth defects, problems with heart muscle or heart valves, and inflammation of the heart.

An EKG has no serious risks. The test doesn't give off electrical charges, such as shocks. You may develop a mild rash where the electrodes were attached. This rash often goes away without treatment.

ECG Machine Handheld ReadMyHeart

How EKG Machines Really Work The EKG machine, abrievated from the German word "Elektrokardiogramm", is a device that records the activity of the heart over time through the electronic impulses transmitted between heartbeats. It was invented in the late 1800s by an Augustus Waller who was the first person to systemically approach the heart from an electrical standpoint. His very first electrocardiograph machine traced the heart's beats with an electrometer fixed to a projector which then launched the information onto a photographic plate fixed to a toy train. Although transformed into a considerably more advanced medical product with the sophisticated technology available, the principles behind the EKG machine remains the same.

Technically, precisely what happens when an EKG machine performs during an operation or the like? The first thing you have to understand is the map of the heart. The heart is basically a pump that has four chambers. The two upper chambers are called the atria and the two lower chambers are referred to as ventricles. A natural electrical system causes the heart muscle to contract and pump blood throughout the body. The sympathetic electrical impulses in the heart occur in the sinoatrial node located in the right atrium of the heart and is then channeled through to the heart muscle where they cause it to contract. What a piece of medical equipment!

In order to physically be able to measure it, a trained EKG technician must selectively place electrodes--which is an electrical conductor through which a current is passed--directly on the patient's skin. Small pads may be placed between the electrodes and your skin to imrpove conduction of the electrical impulses. The electrical waves of different sides of the heart measure the different parts of the muscle. The EKG reading will reflect the results on a digital graph, which can then be traced onto paper for easier analysis. An accurate EKG reading is assessed through a sequence of three waves arbitrarily named P, QRS, and T. The P wave is a low amplitude wave that marks the impulse of both of the areas of the heart's atria which receive blood from the veins of the body. The higher amplitude QRS complex, which is often spiked due to the increase in conduction velocity, measures the depolarization of the ventricles. Finally, the T wave oppositionally shows the depolarization and renewal of the ventricles.

ECG Machine Handheld ReadMyHeart , is a device with which you can record your heart's electrical activity in just 25 seconds, view the key parameters on the LCD screen, and later print the trends in heart activity to help your physician detect CardioVascular Diseases.

Monitoring heart's rhythm is made easy, as Personal ECG is a palm-sized device which can take measurements at any time, in any place, whether it's while eating in a restaurant, after exercising in a fitness center, or after taking a specific drug.

Heart disease, the #1 killer

Did you know? Heart related diseases kill more than all the cancers combined. They are also called the “silent killer”, as you may not have any symptoms until the heart attack. Or you may feel discomfort sometimes, but by the time you visit the clinic, the symptoms are gone.

CardioVascular Diseases are the #1 killer in the USA and account for more deaths than all types of cancers combined. Don't take your heart for granted: prevention and monitoring of your heart's health using Heart Rate Monitors are vital steps towards a long and healthy life - remember to keep your heart active through daily exercise; maintain a balanced diet, quit smoking, keep your body hydrated, and monitor your heart's health with handheld electrocardiogram.

Early detection using Heart Rate Monitor is the key to treatment

Early detection gives your doctor more choices to treat the heart disease and will save time, money or even a life. Monitoring blood pressure using Heart Rate Monitors is important, but directly measuring your heart’s activity with personal ECG Machine brings you one step closer in the detection of heart disease.

Better monitoring of trends and assessment of heart health over time: daily monitoring of your heartbeat parameters will reveal trends in heart health and help your doctor in detecting CardioVascular Diseases.

Timely measurement for timely treatment: timely measurement of cardiac rhythm during certain symptoms or event can help your physician assess your heart health.

Reduction of risks associated with drugs: its portability and short recording time make checking for drug effects on your heart easy: record, then print for your physician to assess whether a drug is putting your heart at risk.

More treatment options when a CVD is detected: earlier detection means wider treatment options when a CVD is detected. Earlier detection and early treatment can mean fewer drugs,

prevention of surgery, and can even save your life.

CVD Facts:

Many common factors contribute to CardioVascular diseases including: Age, gender, ethnicity, genetic heritage, weight, inactivity, and diabetes. Take your heart's health into your hands: monitor your heart with ECG Machine.

How does ECG Machine work?

Electrical waves travel through the heart chambers to charge and trigger heartbeats. If the heart's chambers are not synchronized, the blood will not circulate effectively, which can be a symptom or cause of CardioVascular disease. With Personal ECG Machine, you can measure and record your heart's electrical signals as they are emitted through your body.

When your thumbs are in contact with the dry electrodes, the palm-sized device is able to trace and record the micro-current your heart generates during heartbeats, generating the related heart function parameters (PR, QRS, ST).

Handheld ECG Machine is hassle-free: the LCD displays your key heart parameters (QRS, ST), blinks if they are out of range and stores up to 30 records. Download the records on your computer to easily monitor the trend in your heart health with the included software, then print the numbers and trend for your next doctor’s visit.

After each measurement, Heart Rate Monitor stores the key heart parameters, which when downloaded onto a PC, show trends in heart activity over time. Printed trends in heart activity can then be used by physicians in their diagnosis of CardioVascular Diseases. Don't take your heart for granted!

Prevention

Eating healthy & exercising are key in preventing the heart disease. However, there are still

many risk factors you can’t control, such as age, ethnicity, or gender, so check your heart health regularly for abnormalities and trends.

How to Read ECG Electrocardiogramby DR.

The ECG (sometimes called EKG), is short for electrocardiogram. The ECG is one of the most common and important tests done in hospital today.

The electrocardiogram works on the fact that heart muscle is stimulated to contract by electricity and that a normal heart will project this electricity across your chest in a predictable way.

The ecg electrocardiogram has twelve connected electrodes. Each 'lead' acts like one camera angle capturing the path the electricity takes across your chest. By looking at all the printouts of the ecg a trained observer can put them together his/her mind into a three dimensional view of heart activity. Each event in the production of a heart beat makes a characteristic shape or 'signature' on the ecg reading.

Above left is a photograph of a portable ECG machine. And right, you can see how it's connected. There are four 'limb' straps (1) placed around each of your wrists and each ankle. The bulbs (2) are then connected across your chest in predetermined order and a 'trace' of electrical activity drawn by the machine as below.

ECG Q waves Normal ECG Reading ECG T-waves 

 

Certain patterns are read by health practitioners to help diagnose a variety of abnormalities such as abnormal blood chemistry, arrhythmia misfiring, and of course, heart attacks. ECG Q waves and inverted ECG T waves are two diagnostic wave forms seen in old heart attacks and new heart attacks respectively.

Doctors learn to 'read' ecg's by learning these basic patterns to look for, and then fine tune their interpretations through experience reading hundreds to thousands of ECGs. Typically a doctor reads an ecg the way you'd scan a magazine article looking for obvious things that jump off the page, then in more detail from the upper left corner down to the lower right corner.

MLA Citation for School Reports, Links, and Presentations: DR. "How to Read ECG Electrocardiogram." Doctor Secrets! 10/26/2010. < http://www.doctorsecrets.com/medical-tests/how-the-12-lead-ecg-works.html >

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History of the EKG Machine

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As the heart beats, an electrical current is pumping through it as well. Were it not for this pulse, the heart would not be able to contract and push blood throughout the body. However, if the electrical signals in the heart are abnormal or out of synch, a person’s heart will not operate properly.In 1877, the electrocardiograph, or EKG machine, was first created by Augustus Waller. The machine was designed to interpret and graph the electrical activity of the heart and measure the heart-rate and rhythm of the heart muscle.An EKG machine works by strategically placing electrodes on the skin of the arms, legs and chest. Most of today’s machines use 12 to 15 separate electrodes, but there are some machines that only use three. As the patient’s heart beats, the electrodes transmit the signals of the heart to the EKG monitor, which translates the activity into a sequence of three waveforms. The waves are called P, T, and QRS. P waves are short and mark the activity in the heart’s atria. QRS waves measure the heart’s ventricular activity, and T waves are formed when the ventricles are renewed.The test itself is painless and will not create any kind of electrical shock, but it is important for doctors to be aware of any medications a patient is taking. Some doctors will order an EKG stress test as well, which requires the patient to run on a treadmill while hooked up to machine’s electrodes. A stress test evaluates the heart’s activity while it is in more intense demand for oxygen.Overall, EKG machines are a very valuable tool for doctors to diagnose the cause of chest pains, shortness of breath or heart palpitations. Doctors look for abnormalities in the duration, direction and amplitude of the waveforms, as well as the results of other tests, before offering a diagnosis.

Posted on October 25, 2010 in Used Medical Equipment, ecg machine, ekg machineTags: ecg, ECG Machines, EKG, EKG Machines, Used Medical Equipment | Permalink | CommentTechnorati Tags: ecg, ECG Machines, EKG, EKG Machines, Used Medical Equipment

The EKG Machine – An Indispensible Diagnostic Tool

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As a physician or healthcare provider who purchases medical equipment, it is important to make an educated buying decision when choosing an EKG machine. These machines all work with the same basic technology, but some are more reliable than others. A critical machine like an EKG can be used in various ways to diagnose heart disease or heart abnormalities in patients, so it is important to choose the right machine to meet the needs of your organization.

When physicians suspect heart disease, the first piece of equipment they turn to is an electrocardiograph, also known as an ECG or EKG machine. By detecting and recording the heart’s electronic impulses, EKG technicians can diagnose heart problems, but it is best when this test is administered along with a comprehensive physical exam.

The test is usually performed while a patient is lying on an examination table, however sometimes a physician may use an EKG machine in a stress EKG test. A Stress Test requires the patient to walk on a treadmill while the activity in their heart is recorded.

EKG machines work by connecting up to 12 leads, or electrodes to a patient’s chest, arms and legs. By testing the heart’s activity from various angles, doctors can look at several different readings simultaneously.

The readings from an EKG machine appear on a monitor in the form of waves, and these tracings are also printed out on a roll of paper. Once complete, a technician will often mark certain areas on the report for the doctor to review later.

EKG machines are a critical component in the discovery of heart disease and other heart abnormalities, and should be purchased with the utmost attention to detail. For the best prices on the latest machines, start your search with a used medical equipment dealer.

Posted on October 15, 2010 in ECG Machines, EKG Machines, Used Medical EquipmentTags: ecg, ECG Machines, EKG, EKG Machines, Used Medical Equipment | Permalink | CommentTechnorati Tags: ecg, ECG Machines, EKG, EKG Machines, Used Medical Equipment

Maintaining and Monitoring Your Heart Health

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A healthy diet, lots of exercise and regular testing on an EKG machine are three of the best recommendations a cardiologist can give, especially to patients with a family history of heart disease. However, maintaining good heart health doesn’t stop there.

The heart is the body’s most important organ, and it is heart problems are far more worrisome than almost any other health issue. Surprisingly, many people around the world pay very little attention to the heart. As a result, pharmaceutical companies who make drugs for hypertension are thriving, and doctors are starting to administer EKG testing on patients at younger ages than ever before. Even with early intervention, drug therapy and surgery, heart disease is still among the number one killers of people who live in the United States, Canada, England and Australia. As aging population grows, it is more important than ever to adopt a preventative strategy.

Maintaining a Healthy Heart

When it comes to keeping the heart healthy, many people are fighting against the odds. Family history, obesity, smoking, lack of exercise and a poor diet can do a lot to damage the heart. Absent a complete change in habits and regular EKG screenings, a surprisingly large percentage of people will develop some form of heart disease. Both men and women are at risk.

As for vices, there are a few that can actually lower the risk of heart disease. One of these is the consumption of red wine, which is rich in antioxidants and has been shown to lower HDL cholesterol levels in many patients. Another is sexual activity, which releases positive hormones that have a calming effect on the body and mind.

Eating fresh fruits and vegetables, cutting back on salt and fat, and walking for a few hours every week are a few important ways to make a difference in heart health, but nothing can replace regular visits to the doctor. Annual checkups should always include a complete blood test, blood pressure monitoring and a stress test that measures the heart’s rhythms while hooked up to an EKG machine.

EKG Machines: Effective Before and After a Heart Attack

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As most people are already aware, the leading cause of death is a heart attack. Also known as a myocardial infarction, a heart attack occurs when the circulation of blood through the heart is interrupted by a blockage in one of the coronary arteries. While most fatal heart attacks occur in people with several risk factors for heart disease, there are many preventative measures that can be taken to prevent them. Regular physical exams, including a stress test on an EKG machine, are required in order to diagnose and treat heart disease.

The Versatility of EKG Machines

However, while most patients think EKG machines are used for preventative diagnostics only, they also play an important role in post-heart attack care. For example, it is possible to have a heart attack without even realizing it. ECG waves will be pick up signs of a previous attack and help prevent a more severe myocardial infarction down the road. EKG machines can also be used to assess the damage from a heart attack by measuring the strength and duration of the heart’s electrical signals and the rate at which the heart is pumping blood through the body.

Risk Factors for Heart Attacks

With regular medical testing and a healthy lifestyle, it is possible to prevent heart disease – even in people whose family members have all suffered from heart problems. Patients should be aware of any pain in the chest, neck or left arm, as well as other symptoms like shortness of breath or nausea that occurs at the same time. The