An ECGElectrocardiogram; also called an EKG; a representation of electrical voltage measured across the chest over a period of time. 1. Six Second ECG Guidebook (2012), T Barill, p. 196 is a graphical display of electrical energy generated by the heart over time. ECG graph paper records this cardiac electrical activity, printing at a rateHeart Rate; calculated by counting the number of QRS complexes in six seconds and multiplying by 10; rate is also determined by measuring the number of large squares between two R waves; i.e. –1 large square = heart rate of 300/minute. of 25 mm/second. The paper graph is divided into small 1 mm squares with thicker lines present every 5 mm. It follows then that the width of an ECG tracing is a measurement of time.
Cardiac monitors usually offer two mediums to help identify ECGs: the dynamic ECG viewed on the monitor’s display screen and the static ECG printed on paper. While the screen of a cardiac monitor is useful for recognizing and interpreting rhythms, printing out the ECG on specialized paper provides a much more robust electrical picture of the heart. ECG paper allows for concise measuring of rates, intervals, segments and waveforms.
An ECG is a graphical display of electrical energy generated by the heart over time. ECG graph paper records cardiac electrical activity at a rate of 25 mm/second. The paper is divided into small 1 mm squares with thicker lines every 5 mm.
It follows then that the width of an ECG tracing is a measurement of time. For example, a horizontal accumulation of 25 small 1 mm squares measures electrical activity over one second (as does 5 large squares produced by the thick lines). A six second strip contains a cross-section of 150 small 1 mm squares (6 seconds x 25 small squares/second) or 30 large squares.
Most brands of ECG paper also include hash marks that extend the thicker vertical lines to provide a visual reference for periods of one second and three seconds. This is depicted in Figure 4.8. These hash marks occupy either the top or bottom of the ECG paper strip.
The height (amplitudeThe height or depth of waves and complexes of an ECG in millimetres; represents millivolts where 10 mm is 1 millivolt with a properly calibrated monitor. 1. Six Second ECG Guidebook (2012), T Barill, p. 190) measures electrical voltage. If calibrated properly, a waveformA wave of an ECG. 1. Six Second ECG Guidebook (2012), T Barill, p. 209 with a height of 10 mm equals 1 millivolt. The comparative height or depth of waveforms can yield significant insight about the heart (i.e. ischemiaInsufficient supply of oxygen to meet the oxygen demands of tissue. Anaerobic metabolism becomes increasingly important during periods of ischemia. Ischemia results from an inadequate blood flow that fails to meet the oxygen demands (energy demands) of tissues. If tissues... monitoring).
Figure 4.8 provides details of ECG paper. Note the larger hash marks that indicate 3 second intervals. Two 3 seconds intervals (6 seconds) is often used to determine heart rateThe number of QRS complexes per minute; note that HR may not equal perfused pulse rate. See also: - Step 1 Heart Rate - Rate - Rule of 300s (Triplicate Method) - Six Second Count - The Caliper Method 1.....
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 73-74