Ecg - Electrocardiogram

Introduction

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

Power lab

Five lead shielded Bio camp & snap-connect Lead Wires

Three reusable clamp electrodes or disposable adhesive electrodes

Electrode cream

Ballpoint pen

Push button switch

Stethoscope

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.

Results

Attached graph

Calculation of Heart Rate = 60 / (time interval)

For example: Heart Rate = 60 / 0.762 = 79bpm

Discussion

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, and S deflection. The QRS complex represents the