Transcript Presentation

Basic EKG
Interpretation
What is an EKG?
Also called an ECG, it is an
electrocardiogram
Recording of the heart's electrical activity
A series of "waves" that represent the
electrical impulses
Can be used to monitor patients for
extended periods of time
Can be used to test for heart conditions
The Sinoatrial (SA) node starts the
electrical impulse, which travels down
the heart.
Electrodes are placed on specific points of the body.
One electrode is placed on each limb (but are frequently placed on
shoulder and hip areas)
The other electrodes are placed as follows:
• V1- 4th intercostal space, R of sternum
• V2- 4th intercostal space, L of sternum
• V3- 5th intercostal space, halfway
between V2 and V4.
• V4- 5th intercostal space, Left
midclavicular line.
• V5- 5th intercostal space, L anterior
axillary line.
• V6- 5th intercostal space, L
midaxillary line.
An example
of electrode
placement for
EKG.
The electrical impulses cause the heart
muscles to contract. The impulses are
visible as waves, and each wave can be
linked to when each part of the heart
contracts.
WHAT DOES EACH WAVE AND SEGMENT MEAN?
•P Wave - The SA node has
started an impulse, and the
atria contract
•QRS complex - The
Ventricles contract, and the
cells of the atria repolarize (rest
and recharge)
•T Wave - The cells of the
ventricles are repolarizing
(resting and recharging, so
they can contract again)
•U Wave - are not always
present. When they are
present, they are small. U
waves follow T waves. The
source of the U wave is not fully
understood, but really large U
waves, or inverted (upside
down) U waves can indicate
problems.
HOW DO YOU DETERMINE THE HEART RATE (HOW MANY
TIMES PER MINUTE THE HEART BEATS)
•Heart rate is measured in beats per minute (bpm)
•On the EKG strip, look at the paper. Each big box represents 0.2
seconds.
•How many big boxes does it take to make 1 second???
This is one "big box" ... 0.2 seconds
NORMAL SINUS RHYTHM
•The SA node "fires" (sends its impulse) about 60-100 times per minute for the
average adult. 60-100 bmp is the normal adult heart rate.
• The heart rhythm will be regular and constant, meaning that the waves will occur
at regular intervals (versus being irregular, occuring at varying intervals)
•The height (voltage) and spacing of the waves will be "normal" (you will not need
to measure voltage or milliseconds for this lesson).
•Sinus Rhythm can look like any of the following
Watch Normal Sinus Rhythm
Sinus Bradycardia - Occurs when you have a
regular rhythm and normal waveforms, but the rate is
slower than 60 bpm.
Sinus Tachycardia - Occurs when you have a regular
rhythm and normal waveforms, but the rate is greater than 100
bpm for adults.
This is a 6-second recording. Can you
estimate the rate in bpm?
Sinus Arrhythmia - Occurs when the waveforms
are normal, but the rhythm is irregular. The heart
rate may speed up and slow down.
Can you label the following?
A. Sinus Rhythm
C. Sinus Tachycardia
B. Sinus Bradycardia
D. Sinus Arrhythmia
Atrial Fibriliation - An arrhythmia in which the electrical current
does not begin in the SA node, and the electricity in the heart is
disorganized. The atria do not contract normally, but instead, they
fibrillate (quiver).
The rhythm is irregular, and there is not always a distinct P Wave.
A-fib can increase the risk for stroke due to clot formation.
Many patients with A-fib will be on anticlotting medications.
Watch Video on AFIB
Atrial Flutter - occurs when the electrical signal in the
atria travel in a circuit, causing the atria to contract more
than normal. On the EKG, you will see a "sawtooth"
pattern of P Waves. The rhythm is more regular than
that of A Fib.
Watch AFL
Premature Ventricular Contractions - PVC's, an occasional extra
contraction of the ventricles. These do not pump blood out of the
heart, since the atria have not had a chance to pump blood into the
ventricles. Feels like a "flip flop" feeling in the chest.
Ventricular Tachycardia - An area of the ventricle takes
over as the pacemaker, and creates a rapid contraction of
the ventricles.
There will be no pulse, as blood will not be pumped out of
the heart.
The patient may lose consciousness or die if this condition is
not treated.
The condition can be treated with chest compressions and
defibrillation.
Watch VTACH
Ventricular Fibrillation - vfib, chaotic irregular electrical activity
within the ventricles. No QRS complexes are seen. Basically, the
ventricles quiver.
There will be no pulse, as blood will not be pumped out of the heart.
The patient may lose consciousness or die if this condition is not
treated.
The condition can be treated with chest compressions and defibrillation
Watch vtach and vfib
Asystole - There is no electrical activity in the heart, and
shows up as a "flat line" on an EKG.
It can happen suddenly or gradually.
Chest compressions and injected medications may treat
asystole, but a defibrillator will not work!
Watch agonal rhythm to asystole
A "Code Blue" (aka, "code") is called when a person enters
cardiac arrest, experiences pulseless electrical activity (vfib, vtach,
agonal, etc), or asystole and does NOT have an "Allow Natural
Death" order.
These are a FEW of the dysrrhythmias that can occur, and a very basic way
to interpret EKG's.
Questions? Comments?
References:
www.nih.gov
www.medicinenet.com
www.bostonscientific.com
www.quia.com