ECG

Purpose:  The purpose of this exercise is to introduce the student to the electrocardiograph and how it is used to produce a record of the heart's electrical activity called the electrocardiogram or ECG (or EKG).  Aspects of the ECG will be discussed.

Materials and Methods:  This investigation requires an Intelitool apparatus called Cardiocomp, computer, and LCD projector.  Electrodes will be placed on a student volunteer(s) and the recorded ECGs will be projected on a screen using an LCD projector.

Experiment:  The ECGs observed on the screen should be similar to the top diagram shown below:

Have your ECG printed out and label the P wave, QRS wave, and the T wave on it.  Make sure you identify the length of one or two of the cycles.  Once the length of a cycle is known, calculate the number of heart beats per minute. (Divide 60sec by cycle length.)

Conclusion:  What is the average length of the cardiac cycle at rest?

What does the P wave indicate?

What does the QRS wave indicate?

What does the T wave indicate?

What does the P-Q (or P-R) segment indicate?  Explain you answer using the model below.

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