The phenomenon of R waveFollowing the depolarization of the interventricular septum, ventricular depolarization then progresses from the endocardium through to the epicardium across both ventricles producing an R wave and an S wave. An R wave is the first positive deflection of the QRS... progression utilizes the following six leads: V1, V2, V3, V4, V5, V6. The chest leads provide information on the sagittal plane from the anterior surface across to the lateral surface of the heart.
Notice in Figure 6.17 how the R wave in lead V1 is small (predominant S waveAn S wave is the first wave after the R wave that dips below the baseline (isoelectric line). The end of the S wave occurs where the S wave begins to flatten out. This is called the J point. Figure...), with the R wave progressively increasing in 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 in leads V4 to V5. The R wave (upright wave of the QRS complexThe electrical representation of ventricular depolarization; the atrial repolarization is also a part of the QRS. ECG interpretation relies heavily on the QRS complex. The QRS complex represents the depolarization of the ventricles. The repolarization of the atria is also...) is the dominant wave by lead V3. This gradual increase in the size of the R wave is called a normal R wave progression.
Abnormal R wave progression can occur with acute myocardial infarctions and right ventricular hypertrophyAbnormal R wave progression can occur with acute myocardial infarctions and right ventricular hypertrophy. Large, dominant R waves in leads V1 and V2 may indicate posterior or lateral myocardial infarction and right ventricular hypertrophy. Poor R wave progression (i.e. not.... Large, dominant R waves in leads V1 and V2 may indicate posterior or lateral myocardial infarctionThe necrosis or death of myocardial tissue due to insufficient supply of oxygen to the infarcted region. The ability to identify cardiac ischemia, injury and infarction is vital in the management of the majority of cardiac emergencies. Most sudden cardiac... and right ventricular hypertrophyVentricular hypertrophy is reflected in QRS axis deviation towards the hypertrophied ventricle, increased amplitude in the QRS complex, altered R wave progression, and possibly signs of ventricular strain - ST depression and T wave inversion. Note that ST changes can.... Poor R wave progression (i.e. not until leads V5 or V6) may signal an anterior infarctionThe necrosis of tissue; acute myocardial infarction involves the acute death of myocardial cells. 1. Six Second ECG Guidebook (2012), T Barill, p. 198.
Because the heart is a three dimensional organ, each of the waveforms may reflect or mirror an opposite region of the heart (reciprocal leads). For example, large R waves in leads V1 and V2 (septal, anterior) may reflect prominent Q waves present in posterior or lateral lead ECGs.
In line with QRS axis deviation, abnormal R wave progression does not stand on its own with sufficient strength to form a diagnosis. Placed with other findings, though, abnormal R wave progression may help support a diagnosis when bolstered by other findings.
Figure 6.17 is a normal 12 lead 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. Note the gradual increase in the size of the R wave across the precordial leads with the R wave becoming dominant by V3 or V4.
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. 171-172