Module 2 - ECG measurements Flashcards
Describe the heart function as a function of time
The SA node is the pacemaker of the heart
Depolarization / contraction of the atrium (P wave)
AV node
AV bundle
LR bundle branches
Purkinje fibres
Depolarization of the ventricles (QRS complex)
Repolarization of the ventricles (T-wave)
What does the term ‘lead’ mean?
Lead refers to the different vectors along which the heart’s depolarization is measured. This system is needed to be able to analyze the ECG systems logically every time
DRAW the three leads
Lead 1 is right shoulder to left shoulder
Lead 2 is right shoulder down
Lead 3 is left shoulder down
Where to the P-wave, QRS complex, and the T-wave stand for?
P-wave is contraction of the atrium
QRS complex is contraction (depolarization) of the ventricles
T-wave is the repolarization of the ventricles
What is the 3D cardiac vector?
It gives the pattern of the cardiac vectors (that are based on the three leads) over time
Gives the pattern of the cardiac vector over time
Give the typical processing steps used in clinical practice over time (for ECG)
- Electrodes / transducing
- Amplification
- Filter
- Analog to Digital conversion
- Post processing (peak detection, qrs detection, event classification, visualize and alarms)
What is going on if the P-wave is long?
P-wave is linked to contraction of the atria. If P-wave is prolonged then there is atrial enlargement. Heart skips beats
What is going on if the P-wave is short
Can indicate AV bypass. Very short contraction of the atria
What does it mean if you have a wide QRS complex
Something wrong with contraction of the ventricles. Can indicate distruption of condction
What does an elevated ST segment mean?
from ventricles depolarization to repolarization. Can indicate a myocardial infarction
What do you see with sinus node dysfunction?
no p-wave
What do you see with AV block
there is a p-wave but no QRS
what do youo see with bundle branch block?
no high r peak, so no smooth contraction
What is the difference between brachycardia and tachycardia?
With tachycardia the heart goes too fast
With brachycardia HR is too slow
DRAWINGS TAB
recognize artefacts
mention all of them and describe what happens”:
Electrical interference; dikke laag op het signaal
Movement artefact: disrupted signal for short time
Techical problem: wandering baseline
Respiration: wandering baseline
Pacemaker spike
Loose electrode: super raar signaal overall
