ECG basics Flashcards
Name 1
QRS complex
Name 2
P wave
Name 3
Q wave
Name 4
R wave
Name 5
S wave
Name 6
T wave
What does orange indicate?
PR interval
What does purple indicate?
ST segment
What does blue indicate?
QT interval
What does green indicate?
PR segment
What does the P wave represent?
atrial depolarisation
What does the Q wave represent?
initial depolarisation of the interventricular septum and is defined as the first negative deflection following the P wave and occurring before the R wave
What does the R wave represent?
reflects depolarisation of the main mass of the ventricles
What does the S wave represent?
signifies the final depolarisation of the ventricles, at the base of the heart
What does the T wave represent?
Ventricular repolarisation
What does the QRS complex represent?
ventricular depolarisation
What does the PR interval represent?
represents the time between atrial depolarisation and ventricular depolarisation
What does the ST segment represent?
end of the QRS complex to the beginning of the T wave
It represents the beginning of ventricular repolarisation.
What does the PR segment represent?
reflects the time delay between atrial and ventricular activation.
The PR segment also serves as the isoelectric baseline of the ECG
What does the QT interval represent?
The beginning of the QRS to the end of the T wave. Represents the total duration of electrical activity to the ventricles – the sum of ventricular depolarisation and repolarisation.
The interval is the time it takes for the heart to contract and refill with blood before it beats again
What does the ‘c’ in the QTc stand for?
Corrected
Why is the QTc an important measurement on the ECG? (3)
It is useful in aiding the diagnosis of electrolyte imbalances.
An abnormally short QT interval is associated with an increased risk of developingabnormal heart rhythmsandsudden cardiac death.
An abnormally long QT interval is associated with an increased risk of developingabnormal heart rhythmsandsudden cardiac death.
What is the normal QTc range for an adult male?
350 - 440ms (0.35 - 0.44s) ?
What is the normal QTc range for an adult female?
350 - 460ms (0.35 – 0.46s) ?
What is the normal PR interval range? (Some also refer to this as the PQ range)
120 - 200ms / 0.12s – 0.2s / 3-5 small squares
What is the normal QRS interval range?
<80ms / <0.08s / < 2 small squares ?
less than 3 small squares, or less than 0.12 seconds in duration.
What is the normal heart rate (HR) range?
60 – 100 bpm
What heart rate (HR) constitutes ‘absolute bradycardia’?
< 40 bpm
