An electrocardiogram, or ECG, is a graphical recording of the electrical events occurring within the heart. Because an ECG is a recording of the heart 's electrical events, it is valuable in diagnosing diseases or ailments that damage the conductive abilities of the heart muscle. When cardiac muscle cells are damaged or destroyed, they are no longer able to conduct the electrical impulses that flow through them. This causes the electrical signal to terminate at the damaged tissue or be directed away from the flow of the signal. The termination or redirection of the electrical signal will alter the manner in which the heart contracts. A cardiologist can look at a patient 's electrocardiogram and determine the presence of damaged cardiac muscle based on the time interval between electrical events.
Material and Methods
A computer system
Chart software version 5.0 or later
Five lead shielded Bio camp & snap-connect Lead Wires
Three reusable clamp electrodes or disposable adhesive electrodes
Push button switch
Step 1: Connecting the push button switch to the BNC socket for input 2
Step 2: Plug the Bio amp cable into the Bio amp socket
Step 3: Connect the leads to earth, CH1 negative and CH1 positive, on the Bio amp cable.
Step 4: Apply the cream to the subject then use the disposable adhesive electrodes for subject 's two wrist and left leg. (Following the Einthoven triangle)
Step 5: Subject needs to be relaxed before starting the reading of the EKG.
Calculation of Heart Rate = 60 / (time interval)
For example: Heart Rate = 60 / 0.762 = 79bpm
A typical ECG tracing consists of five identifiable deflections. Each deflection is noted by one of the letters P, Q, R, S, or T. The P wave is the first waveform in a tracing and represents the depolarization of the heart 's atria. The next waveform is a complex and consists of the Q, R,
References: Marieb, Elaine N. "Human Anatomy and Physiology – Laboratory Manual", 8th Ed. Pearson Benjamin Cummings. 2005, p333. Martini, Frederic H. "Fundamentals of Anatomy & Physiology", 6th Ed. Pearson Benjamin Cummings. 2004, p.701-703.