For this lab, my class looked at the graph and shape of the electrical activity in a heart. During this lab, we were given an EKG which allowed us to monitor a group member’s heart beat on a computer. Through exercises, we learned to recognized and compare the different wave forms in EKGs (P Wave, PR interval, QRS Interval, and T wave shape).
During this lab, my group consisted of Olivia G., Kaitlyn O., and Krystal M. We decided to monitor Olivia G.’s heart rate, so Mrs. Kahn attached 3 pads, or electrode
tabs, onto Olivia’s arms (one on Olivia’s right inner wrist and one on each of Olivia’s forearms where a beat can be detected). After, we connected the leads according to the given diagram: green lead to right forearm, red lead to left forearm and black lead to right forearm. Failure to connect the correct colors to the associated tab can result in a graph that resembles a heart attack.
After connecting the EKG system to the computer, we pressed play to start recording and monitoring Olivia’s heart. At first, the system seemed to malfunction because Olivia flat-lined… With Mrs. Kahn’s help, we tightened the plugs, and the EKG system showed a clear graph of Olivia’s heart beat. With little time left, we switched the green and red leads to get a glimpse of how a heart attack would resemble.
After collecting the data, the monitor showed a clear difference between the EKGs having a normal pulse and a heart attack. The top graph shows a person having a heart attack, while the bottom graph shows a person with a normal pulse. The two are mainly differentiated by the T waves. In the EKG with a heart attack, the T waves are not as prominent in comparison to the T waves of a normal heart.
According to the data from a normal heart, ventricular depolarization proceeds from left to right because the direction from the QRS waves are defined by the shape of the T wave. As the T wave is generally larger than the P wave, the ventricular depolarization proceeds from left to right.