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Electrocardiographic Monitoring
Week 10
33
Nursing
Graduate
10/15/2015

Additional Nursing Flashcards

 


 

Cards

Term
P Wave
Definition

Under normal circumstances, the SA node has the most rapid rate of spontaneous depolarization 

 

This makes the SA node the dominant cardiac pacemaker

 

From the SA node, the impulse spreads through the right and left atria

 

On the ECG, the depolarization of the atria is represented by the P wave

Term
PR Interval
Definition

Once the wave of depolarization has reached the AV node, a delay is seen 

 

The delay permits contraction of the atria and allows filling of the ventircles

 

This delay is PR interval: 0.12-0.20

Term
Shortened PR Interval
Definition

Indicates accelerated conduction

 

Such as seen in WPW syndrome

Term
Prolonged PR intervals
Definition
Indicate conduction block
Term
After passing through the AV node, the impulse is conducted along
Definition

Common bundle of His

 

The left and right bundle branches

 

The distal bundle branches

 

Purkinje fibers

Term
QRS Complex
Definition

Represents the progress of depolarization through the conduction system 

 

Ordinarily duration is < 0.12 seconds

Term
Prolongation of the QRS complex
Definition
Represents delayed intraventricular conduction
Term
Following the QRS complex
Definition

The ECG normally returns to baseline and repolarization begins 

 

Repolarization consists of the ST segment and T wave

 

Although ventricular depolarization occurs along established pathways, repolarization occurs independently in every cell 

Term
J Junction
Definition
The junction of the QRS complex and the ST segment
Term
QT Interval
Definition

Rate dependent, shortening with faster rates

 

Normally 0.44 seconds or less

 

Term
QT intervals > 0.6 seconds
Definition

Have been associated with polymorphic ventricular tachycarida

 

Torsades de pointes 

Term
U Waves
Definition
Can be a normal finding
Term
Prominent U Waves have been assoacited with:
Definition

Hypokalemia

 

Hypothermia

 

Hypomagnesemia 

 

Hypocalcemia

 

Sotalol use

 

Phenothiazine use

Term
Hypothermia
Definition

Associated with U waves

 

and

 

J waves aka Osborn Waves

Term
Inverted U waves
Definition
May be seen in LVH and myocaridal ischemia
Term
Standard Leads
Definition

Bipolar

 

Measuring differences between 2 electrodes 

Term
Electrode Placement
Definition
Placed on right arm, left arm, and left leg forming Einthoven's triangle
Term
Unipolar Leads
Definition

Also recorded

 

aVR, aVL, and aVF

Term
A in the Unipolar Leads
Definition
Leads are augmented by removing resistors from the lead wires
Term
From these 6 leads
Definition

3 bipolar, 3 unipolar

 

The axis of depolarization of the ventricles can be determined 

 

Additional information is obtained when electrodes are placed closer to the heart 

Term
In Precordial Lead System
Definition

The neurtral electrode is formed by the standard leads and the 'exploring' electrode is placed on the chest wall

 

Each lead is indicated by the letter V followed by a number 1-6

Term

Modified Chest Leads

 

(MCL)

Definition
Look only at a single bi polar lead
Term
Variation of 3-lead system
Definition

several exist to view the desired areas of the heart 

 

MCL1 through MCL6 view single precordial leads 

Term

Central Subclavicular Lead

 

(CS5)

Definition

Particularly well suited for the detection of anterior ischemia

 

Lead I is selected

 

Lead II can monitor inferior ischemia 

 

This is probably the best alternative to a true V5

Term

Central Back Lead 

 

(CB5)

Definition

Offers a considerably larger P wave for arrythmia detection

 

Similar detection of ischemia to a true V5

Term
Modified 5-Electrode System
Definition

Permits the recording of the 6 standard leads and one precordial lead

 

The precordial lead is usually placed in the V5 positon for ischemia detection

 

Simultaneously monitoring the leads II and V5 offer the best detection of both arrythmias and ischemic events 

Term
Distance between Vertical Lines
Definition
Represent time intervals
Term
Paper Speed
Definition
25 mm/second
Term
1 mm
Definition
0.04 seconds
Term
Every Bold Vertical Line
Definition
0.2 seconds
Term
Heart Rate can Quickly be Determined
Definition
By Dividing 300 by the number of bold vertical lines between QRS complexes
Term
Horizontal Lines
Definition

Represent Voltage

 

Normally calibrated monitors/cardiograms display 1 cm/1 mV

Term
Operating Room Environment
Definition

The electrocautery is the most important source of interference

 

Radiofrequency energy (800,000- 2,000,000 Hz) accounts for most of the interference 

 

Somatosensory and motor evoked potentials have also been shown to stimulate pacemaker spikes 

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