The baselineThe baseline or isoelectric line is a reference point for the waves, intervals and segments. While the PR segment is often used as the baseline, the TP segment - between the end of the T wave and the beginning of... or isoelectric lineAlso called the baseline, the straight line that is present when no electrical activity is present. The baseline or isoelectric line is a reference point for the waves, intervals and segments.While the PR segment is often used as the baseline,... is a reference point for the waves, intervals and segments. While the PR segmentThe PR segment is the line between the end of the P wave and the beginning of the QRS complex. The PR segment signifies the time taken to conduct through the slow AV junction. This delay allows for atrial kick.... is often used as the baseline, the TP segmentA line between waves. Segments measure time between waves (waves are not included in a segment). While waves are fairly self-explanatory, intervals measure time from the start of one wave to the start of another wave (an interval includes at... – between the end of the T waveThe wave that arrives after the QRS; is a graphical presentation of ventricular repolarization. Expect a T wave to follow every QRS complex. The T wave is a graphic representation of the repolarization of the ventricle. The T wave is... and the beginning of the P waveA wave generated from the depolarization of the atria; the P wave is upright when originating from the SA node. The P wave represents the depolarization of the right and left atria. The P wave begins with the first deviation... – is now generally seen as a more accurate baseline. Note: with fast rates, the TP segment disappears, leaving you with the PR segment as the next best, and only, baseline.
In Figure 4.12, several ECG componentsAn ECG is composed of a series of waves and lines usually ordered into some repeatable pattern. The waves and lines are displayed on either a two dimensional screen or on ECG paper. The height of the tracing represents millivolts... are labelled. Note that a waveformA wave of an ECG. 1. Six Second ECG Guidebook (2012), T Barill, p. 209 is produced when the electrical potential of cardiac cell membranes change. During atrial depolarizationThe rapid influx of positive ions (sodium and/or calcium) into a cell – depolarization is necessary for contraction to occur. A depolarizing wave moves through the myocardium on average along a trajectory or vector. A vector is a force moving..., the atrial cell membranes quickly become more positive producing a P wave. The baseline or isoelectric line represents nothing more than an absence of voltage change to the cardiac cells.
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. 81