ECG parts Flashcards
What does ‘depolarisation’ mean?
Contraction of ventricles/atria
What does ‘repolarisation’ mean?
Relaxing and refilling of ventricles/atria
What does the P wave represent?
Atria depolarise; blood squeezed from atria into ventricles
When does the PR interval start?
At start of P wave
When does the PR interval end?
At start of Q wave
What does the PR interval represent?
The time taken for electrical activity to move between the atria to the ventricles
What does the QRS complex represent?
The depolarisation of the ventricles; blood is squeezed from ventricles to arteries out to body
When does the ST segment start?
Starts at the end of the S wave
When does the ST segment end?
Ends at the start of the T wave
What does the ST segment represent?
Time between depolarisation (contraction) and repolarisation (relaxation) of ventricles
What does the T wave represent?
Ventricular repolarisation (relaxing & refilling)
When does the RR interval start & end?
Starts at the peak of one R wave and ends at the peak of the next R wave
What does the RR interval represent?
The time between two QRS complexes (time between each contraction of the ventricles)
When does the QT interval start & end?
Begins at start of QRS complex
Finishes at end of T wave
What does the QT interval represent?
The time taken for the ventricles to depolarise (contract) and repolarise (relax & refill)
