DATREND Systems AMPS-1, Operating Manual

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AMPS-1 OPERATING MANUAL
3 ECG Normal Sinus Rhythm
3.1 Overview
An electrocardiogram (ECG or EKG) is a recording of the electrical activity of the
muscles of the heart. Electrical impulses cause the heart muscle to pump. These
impulses pass through the body and can be measured at electrodes (electrical contacts)
attached to the skin. Up to 10 electrodes may be placed at standard locations on the
body, providing information from different directions or orientation with respect to the
heart’s ‘standard’ position. An ECG monitor displays the voltage between pairs of these
electrodes (and the muscle activity they represent). This display indicates the overall
rhythm of the heart, and weaknesses in different parts of the heart muscle.
AMPS-1 simulates normal and irregular heartbeats with adjustable settings for heart
rate, amplitude, and ST Segment elevation/depression.
3.2 Normal Sinus Rhythm
In a normal heart rhythm, the sinus (SA) node generates an electrical impulse which
travels through the right and left atrial muscles producing electrical changes which are
represented on the electrocardiogram (ECG) by the P wave. The electrical impulse
then continues to travel through specialized tissue known as the atrioventricular (AV)
node, which conducts electricity at a slower pace. This creates a pause (PR interval)
before the ventricles are stimulated. This pause is helpful since it allows blood to be
emptied into the ventricles from the atriums prior to ventricular contraction to propel
blood out into the body. The ventricular contraction is represented electrically on the
ECG by the QRS complex of waves. This is followed by the T wave which represents
the electrical changes in the ventricles as they are relaxing. The cardiac cycle, after a
short pause, repeats itself.
ECG Normal Sinus Rhythm/Chapter 3
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