EKG monitoring are used to?
- monitor a patients heart rate
- evaluate pacemaker functions
- evaluate the response to medication
-evaluate the effects due ti diseases or injury to the heart
- to always obtain a baseline recording before, during and after a medical procedure
Electrodes are
paper, plastic, or metal device that contains conduction media which is applied to the patients skin
cables are
the wires that attaches to the electrode and conducts current back to the EKG monitor
Leads are
a recording of electrical activity between two electrodes.
Leads allow viewing of what planes of the heart
Frontal, (coronal) and Horizontal (transverses)
What does a 12 lead EKG do?
provides views of the heart in both the frontal and horizontal planes and views the surface of the left ventricle from 12 different angles using 10 electrodes
How many electrodes does a 12 - lead need?
10
the three types of leads are
- standard limb leads,
- augmented leads,
- chest leads
leads have 2 factors, the first factor is
the dominance of the left ventricle
the 2nd factor is
the position of the positive electrode on the body, and determines which portion of the left ventricle is seen by each lead
a straight line is classed as an
baseline or isoelectric line
a waveform(defection) is
a movement away from the baseline in a + (upward) or - (downward) direction
A biphasic waveform is
partly positive and partly negative
the right foot is considered to be
a positive, negative and ground lead
the frontal plane read the heart in
Superior, inferior, right and left
The horizontal plane reads the heart in
anterior, posterior, right and left
how many leads does it take to view the heart in the frontal plane?
3 bipolar leads, 3 unipolar leads
which leads are standard limb leads / bipolar?
lead I, II and III
which leads are unipolar leads?
AVR, AVl, AVf
the A stands for
augmented
the V stands for
Voltage
The R stands for
Right arm
the L stands for
Left arm
The F stands for
left foot
the 6 precordial leads (chest leads) are
V1, V2, V3, V4, V5, V6
the types of chest leads are
leads that view the heart in the horizontal plane
what leads are considered positive?
Unipolar leads and chest leads
how to tell if lead I is positive
count the many L's in left arm (1)
how to tell if lead II is positive
count the many L's in left leg (2)
how to tell if lead III is positive
count the many L's from left arm, left leg (3)
aVR, aVL, and aVF are known as the:
(center, middle, midway, Midpoint)
the electrical activity from the midway between Left arm, Left leg to right arm is
usually negative, if it doesn't produce a negative deflection you may place the leads wires incorrectly
When no electrical activity is detected it's called
a baseline or isoelectric line (a straight line is recorded)
There are three types of leads in this order
Standard limb leads, augmented limb leads, and chest leads
Frontal plane leads view the heart from the front of the body as if it were flat. Directions in the frontal plane are
superior, inferior, right and left.
Six leads view the heart in the frontal plane
3 bipolar leads and 3 unipolar leads.
Standard limb leads or (bipolar)
Consists of two electrodes if opposite polarity
Standard limb leads or bipolar leads are
Leads 1, 2 and 3
Leads that consist of a single positive electrode and a reference point are called
Unipolar leads or augmented limb leads
AVR, AVL, and AVF are
Augmented limb leads which are all positive
Since the negative electrode is found at the electrical center of the heart and
All chest leads are positive and considered unipolar leads or augmented
Lead AVR records electrical activity from midway between the left arm and left leg to the right arm
Is usually a negative deflection, if it does not produce a negative deflection, you might have the lead wires placed incorrectly
is when the heart muscle contracts
systole
is when the heart muscle relaxes
diastole
what occurs when the heart relaxes?
the chambers of the heart fill with blood, and a person's blood pressure decreases.
The " lub" is the
first heart sound (S1)
What causes the Lub sound?
by the closure of mitral and tricuspid valves at the start of systole
the second heart sound is
Dub (S2)
what causes the second heart sound?
by the closure of aortic and pulmonic valves, marking the end of systole.
What is the myocardium responsible for?
responsible for the heart's pumping action, which supplies the entire body with blood
What does the myocardium consist of?
cardiac muscle, a type of muscle unlike any other muscle in the body
the ecg is recorded at ____mm/sec, calibrated at ____mm/sec
25, 10
what does the y and x axis represent?
the x axis represents time and the y axis represent amplitude and voltage