Lecture 4 - The Heart Axis Flashcards
(47 cards)
What is flat line also known as?
Asystole
What is asystole?
A condition in which the heart ceases to beat (no systolic beat) No proper ventricle activity
What is the preferred method of restart?
CPR and/or injection with vasopressin
The equipment: lead
Place on body and it would record a voltage shift as the waves of electrical activity sweep over the heart
If the wave is traveling in the direction of (parallel to) the lead…
It will give a strong signal
If the wave is travelling perpendicular to lead…
It will give no signal as the voltage is not being changed in favour of the positive or negative electrode
Where does a wave of depolarisation travel toward?
Positive lead - positive deflection of the ECG trace
A wave of repolarization travel toward
Positive lead results in the opposite
What results in opposite deflections?
Waves travelling away from positive electrode
What is fibrillation?
When the heart is totally out of sync
What is tachycardia?
Ventricles are beating too fast
What is the Einthoven’s triangle?
Imaginary formation of 3 limb lead in a triangle used in electrocardiography formed by 2 shoulders and pubis
What is lead I?
Right arm to left arm
What is lead II?
Right arm to left leg
What is lead III?
Left arm to left leg
What does the electrode placed on the right leg serve?
As a ground and does not record Reduces noise interference
What are the unipolar leads?
avR, avL and avF
What is he direction of ECG dependent on?
The direction of the depolarisation and depolarisation wave moving across the heart
What is used to view the heart?
2 leads One lead: positive electrode Other:negative electrode
What does unipolar lead measure?
Electric impulses at only one only one point
avR (augmented vector right)
Positive electrode right shoulder
avL (augmented vector left)
Positive electrode left shoulder
AvF (augmented vector foot)
Positive electrode on foot
What can one wave of AP give?
Higher or lower recordings depending on which lead you are considering
