Over intracardiac tracings and figures in landscape format. Defines the integral role of "traditional" EGM analysis.
- Maneuver Analysis Everton vs Man C.
- Maneuver Analysis Everton vs Man C─影片 Dailymotion.
- The FCEM Notebook: Revision notes and clinical resource for emergency physicians!
- About This Item!
- Electrophysiological Maneuvers for Arrhythmia Analysis.
Electrophysiology for Clinicians. A concise text to the clinical understanding of basic cardiac electrophysiology and the indications for patient referral.http://daquidezanos.co/wp-content/3935.php
Electrophysiological Maneuvers for Arrhythmia Analysis (Electronic book text, 1st edition)
Electrophysiology: The Basics. A clear, non-technical style, a new full-color Emergency Cardiology Second Edition.
Throughout the book the authors employ an evidence-based No further sub categories. Lai, Luc L. ARKs anbefalinger. Det finnes ingen vurderinger av dette produktet.
Bookstore | Page 3 | AER Journal
Vis forrige. Tips en venn. Mottakers e-postadresse:. Consider finally that the pacing catheters may also not be exactly where you think they are. This partial list emphasizes the need to exercise care and judgment in interpreting any maneuver. There are a plethora of EP maneuvers and "new" maneuvers continue to be published.
This is much less intimidating to the novice if one considers that the great majority are derivatives of a few simple principles such as that of "geography" described previously and the concept of "fusion and reset. This doesn't mean necessarily at a molecular or even cellular level but, for practical purposes, the electrophysiologist needs to know the mechanism well enough to define critical tissue to be ablated while limiting collateral damage to normal tissues. Most clinical tachycardias can be thought of as being either "reentrant" or "focal" although clearly fibrillation, torsades de pointes, and others need to be thought of differently.
This is illustrated graphically in Figure 1. Figure 1. The depolarization resulting from the extrastimulus here is unable to penetrate the circuit to conduct antidromically over the circuit due to refractoriness. However, the same circuit may get into the gap orthodromically and preexcite or advance the "tail" of the circuit. This may advance, delay, or terminate the next cycle depending on the properties of the circuit.
Such a circuit is said to be "reset," although it is possible that reset is not discernable if slowing in the circuit due to prematurity balances the precocity of the extrastimulus. One can appreciate that coincidental reset and fusion are only possible if the circuit or underlying mechanism has an excitable gap with a "separate entrance and exit. These include size of the excitable gap as determined by conduction time and refractoriness , proximity of the pacing site physically to the excitable gap, and physical barriers e.
[PDF] FREE The Ventricular Arrhythmias of Ischemia and Infarction: Electrophysiological Mechanisms
Consider the same extrastimulus in the case of the focal source of tachycardia in Figure 1. It is easy to envisage fusion with collision of the wave from the pacing site with the wave from the focus. However, the wave from the focus in essence creates a protective barrier of refractoriness after discharge such that the tachycardia "generator" is not susceptible to disruption i.
That is, both fusion and reset are not possible with a focus. Conversely, one can potentially penetrate the focus reset but it is only when there is no ring of refractoriness around the focus from its own depolarization, i. The importance of this concept is well illustrated with a clinical example using the quintessential model of macrorentry, namely atrioventricular reentrant tachycardia AVRT using an accessory AV pathway as part of the circuit. This tracing Figure 1. The p is negative in lead II, suggesting low to high atrial activation. A premature ventricular contraction PVC from the right ventricular apex RVA is delivered at a time when the His bundle activation is completed, i.
This delays the next atrial cycle, a situation that is only compatible with an accessory AV pathway as the retrograde limb of an AV reentrant circuit. This is the well-known "His refractory PVC" that is a fundamental of clinical electrophysiology predicated on the fact that the subsequent atrial depolarization can't be influenced via the normal AV conduction system if the His bundle is refractory. The "reset" indicates that the extrastimulus has penetrated the circuit to alter the subsequent cycle.
In the preceding example, the extrastimulus has delayed rather than advanced the next cycle since the AP in question exhibits cycle length dependent prolongation of conduction time.
Electrophysiological Maneuvers for Arrhythmia Analysis
Most APs have a relative constant conduction time independent of cycle length curve C , whereas some prolong the conduction as a function of more premature coupling of the extrastimulus curve B. Whether the reset advances 3 for both curves , delays 2 for curve B or terminates 1 for both curves , the tachycardia depends on the degree of prematurity of the extrastimulus relative to the advancing wave front to the AP. Atrial activity is evident long VA interval with a one-to-one AV relationship. In fact, the coupling interval of the PVC ms only preempts the next anticipated QRS by 70 ms, which, by a simple calculation if the tachycardia is sufficiently regular , places the arrival of the anticipated anterograde wave over the normal AV conducting system 70 ms after the stimulus artifact.
- Bookstore | Page 3 | AER Journal!
- Electrophysiological Maneuvers for Arrhythmia Analysis!
- Electrophysiological Maneuvers for Arrhythmia Analysis | RadcliffeCardiology.
- The Golden Enemy.
- Green Solvents I: Properties and Applications in Chemistry.
- Customer Reviews.
- Electrophysiological Maneuvers for Arrhythmia Analysis;
This must then be fused even if the "pure" paced QRS is not available for inspection not shown, but the entirely paced QRS was indeed wider.