Electrocardiogram (ECG) Flashcards
When electrical signals pass across the heart muscle it has been depolarised. What does this mean?
- Depolarisation occurs when stimulus causes channels in membrane to open and allows Na+ ions to flow in and P- ions to flow out
- This raises the charge inside the membrane
What happens when the heart muscle has been re polarised?
- Na+ ions flow out
- P- ions flow in
In an ECG you need to know:
- Too fast
- Too slow
- Deadly
What are you looking for in an ECG?
Heart rate changes
What is the average bpm resting?
60-80 bpm
What is it called when the heart rate is above 80 bpm?
Tachycardia
What is it called when heart rate is below 60 bpm?
Bradycardia
What are the factors that affect heart rate?
- Stress
- Genetics
- Blood pressure
- Exercise (short term & long term)
- Drugs
- Other illnesses
- Age
- Diet
What is the formula to get beats per second from ECG graph?
No. Of squares in 1 sec / no. Of squares from R to R x 60
What is arrhythmia?
An irregular heart beat- a problem with the rate or rhythm of the heart
What is ECG full form?
Electrocardiogram
What does the small boxes horizontally indicate?
Time (seconds) 0.04 seconds
What does the big box horizontally indicate?
Time (seconds) 0.2 seconds
What does the small box vertically indicate?
Voltage (Millivolt) 1mv
What does the big box vertically indicate?
Voltage (millivolt) 5mv
