EKG Flashcards
Describe the conduction state of cardiac cells during Resting Membrane Potential, Depolarization and Repolarization?
RMP: Polarized
- *Depolarization:**
- Stimulus - Action Potential - Cell to Cell
- Polarity Reverses due to ionic fluxes (Ca++, Na+, K+)
- *Repolarization**:
- Cells return to resting state
What are the five phases of the Cardiac Action Potential?
4 - 0 - 1 - 2 - 3
Phase 4: Resting State
Phase 0: Rapid Depolarization
Phase 1: Initial Repolarization
Phase 2: Plateau phase of Repolarization
Phase 3: Final Repolarization
What is the resting membrane potential of the cardiac muscle?
-90 mV
Action Potential is due to fluxes in which ions?
Sodium, Potassium and Calcium
What is the normal electrical pathway of the heart ?
- Sinoatrial Node (SA)
- Atrioventricular Node (AV)
- Common Bundle (His)
- Bundle Branches:
- Left Anterior Fasicle
- Left Posterior Fasicle
- Right Bundle Branch - Purkinje Fibers
What is the polarization rate of the Sinoatrial Node?
60-100/min
What is the polarization rate of the AV Node?
40-60/min
What is the polarization rate of the Ventricle?
20-40/min
What are the seven steps of the cardiac depolarization sequence?
- Sinoatrial Node (SA)
- R & L Atrium
- Atrioventricular Node (AV)
- Common Bundle (His)
- Bundle Branches:
- Left Anterior Fasicle
- Left Posterior Fasicle
- Right Bundle Branch - Purkinje Fibers
- Myocardium
How does the septum depolarize?
From Left to Right
What is a Monophasic Waveform?
A complex all positive or all negative waveform
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/884/387/a_image_thumb.png?1631415503)
What is a Biphasic Waveform?
A complex waveform with both positive and negative deflections
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/884/584/a_image_thumb.png?1631415574)
What is a Triphasic Waveform?
Three deflections. e.g. rsR’
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/884/624/a_image_thumb.png?1631415669)
What is an Isoelectric or “equiphasic” Waveform?
A waveform where positive and negative (or vice versa) follow one another and are of equal deflection.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/884/642/a_image_thumb.png?1631415837)
What makes a waveform a positive complex?
If the electrical current is traveling towards an EKG lead
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/885/046/a_image_thumb.png?1631416567)
What makes a waveform a negative complex?
If the electrical current is traveling away from an EKG lead
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/885/064/a_image_thumb.png?1631416610)
What makes a waveform a Biphasic complex?
If the electrical current is traveling perpendicular to an EKG lead
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/885/102/a_image_thumb.png?1631416682)
What is R’ called?
R Prime
What does the QRS Complex represent with respect to what is happening in the heart?
Ventricular Depolarization
What does the P wave represent?
1st deflection of a complex; atrial depolarization and contraction.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/885/862/a_image_thumb.png?1631418866)
What is the intrventricular septum?
The wall that separates the right and left ventricles
What is a segment?
A segment is a straight line connecting two waves.
- PR Segment
- ST Segment
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/885/982/a_image_thumb.png?1631418918)
What is an interval?
An interval encompasses at least one wave plus, in most cases, the connecting straight line.
- PR Interval
- QRS Interval
- ST Interval
- QT Interval
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/046/a_image_thumb.png?1631418938)
What does the T Wave on an EKG represent?
Deflection after QRS wave showing Ventricular Repolarization
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/286/a_image_thumb.png?1631418707)
What is the Q Wave?
1st negative deflection after the P wave
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/612/a_image_thumb.png?1631419185)
What is the R Wave?
1st Positive Deflection after the P Wave
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/713/a_image_thumb.png?1631419258)
What is the S Wave?
1st Negative Deflection after the R wave.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/832/a_image_thumb.png?1631419310)
What is the U Wave?
Deflection after the T wave, but it is rarely present
What is the “J” or Junction Point?
Where the QRS complex ends and the ST segment begins. Used to measure ST-segment deviation in relation to baseline.
What is the R-R Interval?
Interval from one R deflection to the next R deflection, which represents one complete cycle.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/965/a_image_thumb.png?1631419653)
What is the TP Segment?
The TP Segment represents electrical baseline and is the segment from the end of ventricular repolarization to the beginning of atrial depolarization.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/886/990/a_image_thumb.png?1631419815)
What are the three inferior leads and their angles?
Limb Leads:
Lead II +60
Lead III +120
Lead aVF +90
aVF - Augmented Vector Foot
![](https://s3.amazonaws.com/brainscape-prod/system/cm/355/887/134/a_image_thumb.png?1631420605)