Electrocardiography Flashcards
What is an electrocardiograph?
Instrument with graph paper that moves under a stylus
How does an EKG work?
Electric currents cause the stylus to move up or down as the paper unrolls beneath it
Describe what is happening during each wave
1. P wave:
2. QRS wave:
3. T wave:
- Atria contract
- Ventricles contract
- Muscle relaxation
Define each. State if it’s systolic or diastolic.
1. Depolarization
2. Repolarization
- Process of generating electrical impulse
- Results from movement of cations into heart muscle cells.
- Systolic - Cations are pumped out of the cell
- Results in the outside of the cell having a more positive charge than the inside of the cell.
- Diastolic
Label where the three leads go on the patient
Principles for Depolarization: (1/2)
If the wave of depolarization is generally moving ___ the positive sensing electrode, that electrode will record a ___ deflection above the isoelectric line on the EKG paper
- Toward
- Positive
Principles for Depolarization: (2/2)
If the wave of depolarization is generally moving ___ the positive sensing electrode, that electrode will record a ___ deflection above the isoelectric line on the EKG paper
- Away
- Negative
Isoelectric line is…
If depolarization is running perpendicular to the positive lead then the results is at the base line
(Line is red in image)
The smallest box on the paper is ___mm.
The largest box on the paper is ___mm.
- 1mm
- 5mm
The speed of which paper comes out of the EKG is typically ___mm per second.
25mm/sec
At the speed of 25mm/sec:
A 1mm box is ___seconds
A 5mm box is ___seconds
1mm box = 0.04 seconds
5mm box = 0.20 seconds
To determine a HR from an EKG strip, you must obtain a ___ second tracing, which is also ___ five mm boxes. Then you count the number of ___ waves and multiply by ___ to obtain the HR/min.
- Six second
- 30 five mm boxes
- R waves
- 10
What is the HR?
25mm/sec
120 bpm
Work:
12 R waves x 10 = 120 bpm
Amplitude of the deflected waves is measured in ___.
Voltage of a wave deflected thru
FINISH
State what electrodes each lead goes between/measures:
Lead I is from…
Lead II is from…
Lead III is from…
Lead I: Right arm to left arm
Lead II: Right arm to left leg
Lead III: Left arm to left leg
ECG Recording Technique (6)
- Place Pt on clean floor or non-metal table
- Attach ECG leads, moisten w/alc or electrode gel
- Record in right lateral or standing position
- Keep Pt still & calm as possible
- Record lead II for 30-60sec at 25mm/sec
- Record brief brief tracing at 50mm/sec
ECG Pneumonic with colors
Black
Red
White
Green
Black & Red = Smoke over fire
White & Green = Snow over grass
Arrhythmia is…
Any abnormality in the rate, rhythm, or electrical generation of the heart beat.
Arrythmia pathology is abnormal impulse ___ & ___.
Formation & conduction
Abnormal impulse Formation from arrhythmias can be due to… (4)
- Low O2
- Hypocalcemia or hypercalcemia
- Cardiomyopathy
- Heart tissue trauma/injury
Abnormal impulse Conduction from arrhythmias can be due to…
Anatomic defect of electrical conduction system
Pulse deficit demonstrates altered ____.
Hemodynamics
Arrhythmias cause abnormal ___ in the body blood flow. Blood flow to the brain may be decreased from __% to __%
- Hemodynamics
- 8% to 80%
Define each
1. Sinus rhythm
2. Arrhythmia
3. Bradycardia
4. Tachycardia
5. Asystole
- Normal steady rhythm
- Abnormal rhythm
- Slow heart
- Fast heart
- No contraction
In a canine, bradycardia is ___bpm and tachycardia is __bpm or ___bpm in giant breeds.
Bradycardia: <60bpm
Tachycardia: >180bpm; giant >160bpm
Atrial Fibrillation has no organized ___ contraction, but “quivering” muscle tissue. ___ cardiac output due to poor ventricular filling of blood.
- Atrial
- Decreased
Atrial fibrillation Dx (2)
- Auscultation - “Tennis shoes in the dryer”
- EKG doesn’t have a P wave
Premature Ventricular Contractions is when a heart beat is ___ generated from the Bundle of His ___ of the SA node.
- Spontaneously
- Independent
PVCs
Causes (4)
Dx (2)
Cause
1. Hypoxia or heart trauma
2. Anesthesia or toxins
3. Heart disease
4. Electrolyte abnormalities
Dx
Pulse deficit or EKG
Identify this arrhythmia.
Hint: Use the red circle as guidance
Ventricular Tachycardia is a ___ risk rhythm and is usually fatal within ___ days if left untreated.
- High risk
- Two days
Ventricular Tachycardia
Cardiomyopathy, heart ___, myocarditis, heart ___, may cause PVCs. If a HR is ___bpm due to PVCs, ___ ___ may occur and must be treated.
- Failure
- Tumor
- > 130bpm
- SVDDEN DEATH
Which arrhythmia is this?
PVC or Ventricular Tachycardia
“Ghosts holding hands”
Ventricular Fibrillation is identified by it’s electrical activity in the ____. It doesn’t effectively move ___. It is a rapidly ___ rhythm. Although, it may be ___ with an ___ shock of a defibrillator.
- Ventricles
- Blood
- Fatal
- Reversed
- Electrical
Pulseless electrical activity is a common ___ animal arrhythmia (esp under ___).
ECG pattern is visible, but no ___ and no ____ contraction.
It is fatal within ___ if not resuscitated.
- Small animal
- Anesthesia
- Pulse
- Heart contraction
- Minutes!
Patient has no pulse and their EKG looks like this. What is this called?
Pulseless electrical activity
What is this?
How is it caused?
How do you fix it?
- Electrical interference
- IV pump & other machines cause ECG artifacts; also called “60 cycle”
- Solutions:
- Plug ECG into different outlet
- Turn off unneeded equipment
- Switch to battery mode when possible
What is this?
How is it caused?
How do you fix it?
- Movement artifact
- Animal or lead movement
- Restrain to minimize movement
What is this?
How is it caused?
Who is it normal in?
Common in?
- Sinus arrhythmia
- Variation in rhythm associated with breathing
- Normal in canines & humans
- Common in young athletic animals
