Heart 1: ECG - Rest & Exercise
ECG Cable and Pulse Set Up
- Plug the red, black and green leads into the REACH color coded ports.
- Snap the leads onto the stickie electrodes, then place the stickie electrodes like this:
- The black lead goes under the right clavicle.
- The red lead goes on the lower left abdomen.
- The green (ground) lead goes on the lower right abdomen.
Make sure you snap the leads onto the stickie electrodes before putting them on yourself.
- When you are ready to start recording data, just make sure the you relax and sit very still so there is no movement interference on the data.
The ECG and Heart Rate in a Resting Subject
Aim
To measure ECG values and Heart Rate while resting.
Procedure
- While holding the REACH-DL in your hand, use your other hand to click on the Record button.
- Click on the AutoScale button.
- Type "Resting ECG" in the Mark box and click the Mark button. This will make a black mark with text on your screen.
- Record for 5 minutes then click Stop.
- Click File ---> Save As, name the file "ECG-Rest&Exercise", and save your data to your LabScribe Data folder on your Desktop.
Data Analysis
- Go to the beginning of your recording by clicking on the down arrow just to the right of the Mark Button and click the mark "Resting-ECG".
- Make sure to have at least 5 ECG cycles on screen. Double or half the display time by clicking the mountain icons once.
- You will be moving the vertical red cursors into position by clicking and dragging on them to get them into the right locations.
- Place the cursors to measure the amplitudes (V2-V1) and time intervals (T2-T1) of the ECG cycles.
- Use the mouse to click on and drag the cursors to specific points on the ECG recording to measure the following:
- The R-wave amplitude. Place one cursor on the Q wave and the second cursor on the peak of the R wave. The value for V2-V1 on the ECG channel is the amplitude. Measure the amplitudes of two additional R waves. Calculate the mean amplitude by adding these together and then divide by 3.
- The beat period, which is the time interval between two adjacent R waves. To measure the beat period, place one cursor on the peak of an R wave and the second cursor on the peak of the adjacent R wave. The value for T2-T1 is the beat period. Measure the beat period for two additional pairs of R waves and then calculate the mean.
- The P-R interval. Place one cursor at the beginning of the P wave and the second cursor on the Q wave. The value for T2-T1 on the ECG channel is the P-R interval. Measure this time interval for two additional ECG cycles and then calculate the mean.
- The Q-T interval. Place one cursor on the Q wave and the second cursor at end of the T wave. The value for T2-T1 on the ECG channel is the Q-T interval. Measure this time interval for two additional ECG cycles and then calculate the mean.
- The T-P interval. Place one cursor at the end of the T wave and the second cursor at the beginning of the P wave. The value for T2-T1 on the ECG channel is the T-P interval. Measure this time interval for two additional ECG cycles and then calculate the mean.
- Determine your average heart rate.
- Click the "two-mountain" icon to double the display time to show the entire 5 minutes of data. You may have to click it a few times.
- Once you can see all your data, move the cursors to either side of the recording.
- Look at the right side of the Heart Rate channel and read the MEAN value of your resting Heart Rate.
Reset Your Display Time - In the display time box, type 10 and click enter. This will reset your display time to 10 seconds for Exercise 2.
Note - Write all your values on a data table so you can refer back to them when answering the questions.
You can open and close the Journal by clicking the "Notebook" icon.
The ECG and Pulse After Leg Exercises
Aim
To measure the ECG and the pulse immediately after exercise.
Procedure
- After finishing Exercise 1, carefully unsnap the leads from the stickies. Leave the stickies on.
- Exercise for at least 10 minutes - do jumping jacks, go run around, or do some other form of exercise. You should have a very elevated heart rate and be breathing deeply when you are done.
- As soon as your are done exercising, sit down and resnap the leads onto the stickies.
- Click Record. Click AutoScale. While recording, type "0 sec" in the Mark box and click the Mark button.
- Continue recording until your heart rate has returned to normal or for 5 minutes, whichever comes first.
- Enter marks every 30 seconds by typing "30", "60", "90", etc... in the Mark area and click the Mark button.
- Click Stop after 5 minutes even if the your heart rate has not returned to normal.
- Click Save to save your data.
Data Analysis
- Go to the beginning of your recording by clicking on the down arrow just to the right of the Mark Button and click the mark "0 seconds". This will bring you to right when you sat down after exercising.
- Make sure to have at least 5 ECG cycles on screen. Double or half the display time by clicking the mountain icons once.
- You will be moving the vertical red cursors into position by clicking and dragging on them to get them into the right locations.
- Place the cursors to measure the amplitudes (V2-V1) and time intervals (T2-T1) of the ECG cycles.
- Use the mouse to click on and drag the cursors to specific points on the ECG recording to measure the following:
- The R-wave amplitude. Place one cursor on the Q wave and the second cursor on the peak of the R wave. The value for V2-V1 on the ECG channel is the amplitude. Measure the amplitudes of two additional R waves. Calculate the mean amplitude by adding these together and then divide by 3.
- The beat period, which is the time interval between two adjacent R waves. To measure the beat period, place one cursor on the peak of an R wave and the second cursor on the peak of the adjacent R wave. The value for T2-T1 is the beat period. Measure the beat period for two additional pairs of R waves and then calculate the mean.
- The P-R interval. Place one cursor at the beginning of the P wave and the second cursor on the Q wave. The value for T2-T1 on the ECG channel is the P-R interval. Measure this time interval for two additional ECG cycles and then calculate the mean.
- The Q-T interval. Place one cursor on the Q wave and the second cursor at end of the T wave. The value for T2-T1 on the ECG channel is the Q-T interval. Measure this time interval for two additional ECG cycles and then calculate the mean.
- The T-P interval. Place one cursor at the end of the T wave and the second cursor at the beginning of the P wave. The value for T2-T1 on the ECG channel is the T-P interval. Measure this time interval for two additional ECG cycles and then calculate the mean.
- Determine your average heart rate.
- Click the "two-mountain" icon to double the display time to show the entire 5 minutes of data. You may have to click it a few times.
- Once you can see all your data, move the cursors to either side of the recording.
- Look at the right side of the Heart Rate channel and read the MEAN value of your resting Heart Rate.
- Click the down arrow to the right of the Mark button and click "30 sec" to bring you to the section of data 30 seconds after sitting down.
- Repeat the data analysis for this section of data. Measure the same parameters as above.
- Move through the sections of data by clicking the down arrow by the Mark button and choosing the next mark ("60", "90" etc...). Measure the same parameters for each 30 second interval throughout the recovery period. Stop when your heart rate returned to normal and note down how long that took.
Note - Write all your values on a data table so you can refer back to them when answering the questions.
To open and close the Journal – click the "Notebook" icon.