A slurring of the upstroke of the QRSThe 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... produced by early 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... (pre-excitationDepolarization of the ventricle(s) is begun via an accessory pathway (other than the AV junction) resulting in an early initiation of a QRS and possibly a Delta wave; meanwhile, the junction and the His-Purkinje network is responsible for depolarizing the...) of a ventricle via an accessory pathwayAlternative connecting pathway between the atria and the ventricles (beside the bundle of His); resulting syndrome is called Woolf-Parkinson-White syndrome. 1. Six Second ECG Guidebook (2012), T Barill,p. 189 (see Woolf-Parkinson-White Syndrome).
Woolf-Parkinson-White Syndrome (WPW)Pre-excitation syndrome characterized by the early depolarization of the ventricle(s) via an accessory pathway (other than the AV junction) resulting in an early initiation of a QRS and possibly a Delta wave; due to the presence of the accessory pathway,...:
Pre-excitation syndrome characterized by the early depolarization of the ventricle(s) via an accessory pathway (other than the AV junctionConducts the impulse through the fibrous plate that separates the atria and the ventricles; consists of the AV node and the bundle of His; functions also to slow the conduction speed to allow for atrial conduction prior to ventricular conduction...) resulting in an early initiation of a QRS and possibly a Delta wave; due to the presence of the accessory pathway, re-entryOne of several causes of dysrhythmias, the re-entry loop often results in tachycardias; the re-entry loop requires an area with slowed speed of conduction, an proximal area with regular conduction speed and cells that are receptive to depolarizing; the loop... phenomena is possible with resulting rhythms such as atrial tachycardiaA fast rhythm with rates commonly 150-240/minute; QRS complex is most often narrow; rhythm is usually generated from a re-entry loop – often making use of an accessory bundle and the AV node. 1. Six Second ECG Guidebook (2012), T Barill, p. 191; note that a Delta wave is present in only about 5% of people with WPW; those with a Delta wave and in atrial fibrillationOne of the most common dysrhythmias, the atria have a host of sites that are concurrently firing at a combined rate of 350-600/minute; since the junction allows maximum 240 impulses through per minute, the result is a chaotic rhythm most... or atrial flutterA rapid atrial rhythm (approximately 300/minute in the atria) caused by a re-entry loop within the atria; since the junction is unable to conduct 300 impulses/ minute (max=240), the junction often allows every 2nd, 3rd, or 4th impulse through; resulting... are at increased risk of sudden cardiac death – avoid medications that slow conductivityThe ability of a cell to receive and transmit an electrical impulse. 1. Six Second ECG Guidebook (2012), T Barill, p. 194 through the AV nodeIs located in the inferior aspect of the right atria; functions to slow the conduction speed to allow for atrial conduction prior to ventricular conduction (atrial kick); also serves as a pacemaker if the SA node fails to fire. The... such as digoxin, adenosine, calcium channel blockers, and beta blockers.
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. 195