Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/83

Click to flip

83 Cards in this Set

  • Front
  • Back
A wave of depolarization traveling towards a positive EKG electrode causes _ on the EKG tracing
Upward deflection
A wave of depolarization traveling away from a positive EKG electrode causes a _ on the EKG tracing
Downward deflection
A wave of repolarization traveling towards a positive EKG electrode causes _ on the EKG tracing
Downward deflection
A wave of repolarization traveling away from a positive EKG electrode causes a _ on the EKG tracing
Upward deflection
Interval vs segment
In electrocardiography, an interval includes at least one of the waves that it is named after, whereas a segment does not. In other words, a segment is simply a section of baseline which is between the waves that it is named after
distance (time) from beginning of P wave to beginning of QRS complex
PR interval
distance (time) from beginning of QRS complex to end of T wave(includes the QRS complex and the T wave )
QT interval
distance (time) from end of QRS complex to end of T wave
(includes the T wave but not the QRS complex)
ST interval
ST segment - what physiological event
repolarization of ventricular tissue = plateau phase of repolarization
Where on EKG do you see rapid phase of ventricular repolarization
T wave
Physiological event of U wave
repolarization of Purkinje fibers, Purkinje fibers depolarize very fast but repolarize very slowly which causes U wave
The vertical axis of the tracing represents _
Voltage
At standard calibration, _= 0.1 mV
1 mm
The horizontal axis of the tracing represents
Time
At standard paper speed (25 mm/sec.),
1 mm = _ sec. = _msec.
0.04 sec = 40 msec
How many big blocks per second
5
Determination of heart rate for very slow or irregular heart rates
Count the number of cardiac cycles (R-to-R intervals) over 2 consecutive 3 second intervals, and then multiply this number by 10 in order to determine the heart rate in beats per minute
6 limb leads (I, II, III, aVR, aVL, aVF)
Allow determination of axis in the _ plane
Frontal
6 precordial (chest) leads (V1 – V6)
Allow determination of axis in the _ plane
Horizontal
Each has 1 positive and 1 negative electrode
Bipolar limb leads
Each has 1 positive electrode and 1 compound reference electrode (sum of the other 2)
Augmented unipolar limb leads
RA- LA- which lead, where is positive electrode
Lead I, positive electrode on LA
RA- LL which lead where is positive electrode
Lead II, positive electrode left leg
LA - LL, which lead where is positive electrode
Lead III, positive electrode left leg
Lateral leads
I and AvL
Inferior leads
II, III and avF
3 steps for determining the QRS axis in
the frontal plane
-Locate the most isoelectric lead (the lead in which the difference between the amount of QRS deflection above and below the isoelectric line is closest to zero)
-Locate the lead 90 degrees from the most isoelectric lead.
-The QRS axis is along this lead (perpendicular to the isoelectric lead), in the direction corresponding to the polarity of the QRS complex in that lead
Change from negative to positive occurs at V5, V6 or never - rotation?
Left
Change from negative to positive occurs at V1 or V2 - rotation?
Rightward axis rotation
Change from negative to positive occurs at V3 or V4 - rotation?
No rotation, normal
If QRS at chest leads starts negative and ends negative - rotation?
Left
If QRS at chest leads starts positive and ends positive - rotation?
Right
If QRS at chest leads starts positive and becomes negative by V6 - rotation?
Left
Ability of specialized cells to spontaneously generate electrical impulses which may then spread throughout surrounding tissue.
Automaticity
Atrial foci automaticity rate
60-80 per min
Junctional AV nodal foci automaticity rate
40-60
Ventricular foci automaticity rate
20-40
The pacemaker with the fastest rate is the dominant pacemaker
Overdrive suppression
A protective mechanism whereby an automaticity focus with the next highest inherent rate begins pacing in the event of a pause or cessation of pacing activity of the previously dominant pacemaker.
Escape
Transient escape of an automaticity focus (from overdrive suppression) to generate one beat.


This occurs when?
Escape beat -

This occurs when there is a pause in pacing activity in the previously dominant pacemaker.
Escape of an automaticity focus (from overdrive suppression) with subsequent pacing by that automaticity focus, at its inherent rate.

This occurs when?
Escape rhythm

This occurs when there is a cessation (or arrest) of pacing activity in the previously dominant pacemaker.
EKG criteria for sinus rhythm
Each QRS complex is preceded by a P wave.

The P waves must be positive in lead II, and negative in lead aVR.
If you see a biphasic P wave in lead II - what does it mean?
Pacemaker is between SA and AV node - atrial rhythm
P wave is absent - where is the foci
In the middle of AV node
If inverted P wave is after QRS - where is foci
In Purkinje fibers
An increase in the tendency for automaticity foci to spontaneously generate electrical impulses
Irritability
Occurs when an irritable automaticity focus spontaneously generates a single electrical impulse prior to the next expected beat from the dominant pacemaker
Premature beat
Premature beats are caused by _
Irritability
The delay in ventricular depolarization which usually follows a premature beat
Compensatory pause
If SA node is reset - is there complete or incomplete compensatory pause
Incomplete compensatory pause
Most PAC's are followed by _ compensatory pause
Incomplete
Most PVC's are followed by _ compensatory pause
Complete
Sustained arrhythmia
Arrhythmia that is greater than 30 sec in duration
Flutter rate
250-350
Fibrillation rate
350-450
Polymorphic V tach which is preceded by marked prolongaiton of QT
Torsades de Pointes
Torsades de Pointes is due to _
Triggered activity - EAD's related to R on T phenomenon facilitated by marked QT prolongation
Formula for corrected QT interval
QT measured * square root R to R interval
Most common cause of SVT
AV nodal reentry tachycardia
P wave shape varies

atrial rate less than 100

irregular ventricular rhythm
Wandering pacemaker
P wave shape varies

Atrial rate exceeds 100

Irregular ventricular rhythm
Multifocal atrial tachycardia
Short PR + delta waves
WPW syndrome
Short PR + no delta waves
LGL syndrome
1: 1 ratio of P waves to QRS

PR interval is fixed (consistent)

PR interval exceeds 200 msec (5 small blocks, 1 big block)
First degree AV block
Progressive lengthening of PR interval util one of P waves is not followed by QRS
Wenkebach 2nd degree AV block
There are more P waves than QRS complexes

All P waves that immediately precede QRS complexes have equal PR intervals
Type II Mobitz 2nd degree AV blocks
RsR" pattern in V1, wide S wave in leads I and V6, QRS >0.12
RBBB
Broad sometimes notched R wave in leads I (and V6), absent q waves in I, AVL, V6, wide and deep S waves in V1
LBBB
Add mm in V1 (negative) and V5 (pos) if more than 35 and person is over 40 years old_
LVH
Asymmetrical inverted T wave
LVH
Right axis deviation

R higher in V1

Deep S wave in V6
RVH
In sinus rhythm in lead V1 P wave > 1.5 mm high OR > 2.5 mm high in lead II
R atrial abnormality
In sinus rhythm in lead V 1 P wave > 1 mm deep and > 1 mm wide or in lead II > 120 msec in duration (> 3mm wide), can be notched
R atrial abnormality
ST elevation in V2, V3, V4
Anterior MI
ST elevation in V1, V2, V3
Anteroseptal MI
ST elevation in V4, V5, V6 (can also have V2, V3)
Anterolateral MI
ST elevation in V1- V6
Extensive anterior MI
ST elevation in V5, V6, I, AvL
Lateral MI
ST elevation in I and AvL
High lateral MI
ST elevation in II, III, AvF
Inferior MI
ST elevation in II, III, AvF, V5, V6
Inferolateral MI
Reciprocal changes in V1, V2
Posterior MI
ST elevation in II, III, AvF, V5, V6 + reciprocal changes in V1, V2
Inferoposterolateral MI