Basic EP Flashcards
Describe the electrical activity occuring during the PR interval
all elecrtical activity
What part of the AP curve corresponds to the ST segment?
Phase 2
plateau phase
What two pathways can be localized within Koch’s triangle?
Fast: Anterior
Slow: Posterior
Name three major deflection on the HIS electrogram
- A
- H
- V
Which ion occurs during phases 1, 2 and 3?
Potassium
What is extrastimulus pacing which demonstrates the longest coupling interval for which a premature impulse is blocked or fails to propagate through that tissue?
Effective Refractory Period
What is the longest coupling interval to be associated with a blocked premature stimulis?
ERP
What structure extends from the coronary sinus os to the superior aspect of the septum?
Tendon of Todaro
What’s the most common mechanism for arrhythmias?
Reentry
Which phase correlates with the relative refractory period?
Phase 3
Name the three borders of the triangle of Koch
- Septal leaflet of the Tricuspid
- os of the coronary sinus
- Tendon of todaro
How do you measure the AH interval?
onset of the A to the onset of the H on the HIS
Name 2 uses for an EP catheter
- pacing
- recording
Which fluoro view shows the long axis of the ventricles?
RAO
Where is Na+/K+ pump is activated?
Phase 4
What is the longest coupling interval that delays conduction?
RRP
Which ion triggers cardiac muscle contraction?
Calcium
Which ion is responsible for depolarization in a cardiac pacemaker cell?
Calcium
What is the period of time when the initiation of an action potential is impossible no matter how strong the stimulus?
ARP
What percentage of people have the AV nodal artery arising from the RCA?
85%
What is the inherent firing rate of the AV node?
40-60 BPM
How does the electrical conduction travel from the right atrium to the left atrium?
Bachmann’s Bundle
Atrial kick accounts for how much blood into the ventricles?
20-30%
Phase 3 correlates with what on the ECG?
T wave
What view is this?
RAO
What structure is between the IVC and the tricuspid valve in the posteroseptal wall?
Os of the Coronary Sinus
What does the H spike represent on the HIS bundle channel?
Conduction at the His
When is K+ moving out in the AP?
Phase 1, 2, 3
Phase 2 correlates with what on the ECG?
ST segment
What is the inherent firing rate of the His-Purkinje system?
20-40 BPM
What does the AH interval measure?
conduction time though the AV node
What is the ability of the heart to intiate an impulse?
automaticity
Which property is considered inotropic?
contractility
What view is this ?
LAO
What structure is a ridge that runs from SVC to the IVC?
Crista Terminalis
Where is the conduction velocity fastest?
Purkinje Fibers
How do you measure the PA interval?
beginning of the P wave to the onset of the A on the HIS
Why is the electrical impulse is slowed in the AV node?
- Allow for ventricular filling
- Allow for complete atrial emptying
Which mechanism is associated with metabolic causes?
Automaticity
Which fluoro view shows the short axis?
LAO
What does the PA interval represent?
intraatrial depolarization
What does the HV interval measure?
Conduction time through the HIS, Purkinje system
What phase (s) of the AP are repolarization phases?
Phases 2, 3, 4
Which ion is responsible for depolarization in a cardiac muscle cell?
Sodium
What is the period of time in which a cell cannot be stimulated to depolarize early no matter how strong the stimulus?
Absolute refractory period
What does the A spike correlate to on the HIS bundle channel?
Conduction of the low Right Atrium
What is the EP equivalent of heart rate?
Cycle Length
What does the V spike represent on the HIS bundle channel?
Conduction of High Right Ventricle
Which phases correlate with ARP?
Phase 0, 1, 2 and initial portion of 3
What structure is used to gain access to the left atrium?
Fossa Ovalis
How do you measure the HV interval?
onset of the H to the onset of the first QRS on the surface EKG
What side of the screen is the spine in RAO?
Left
What is the basic unit of time in EP?
Milliseconds
Where is the HIS bundle located?
The inferior end of the interatrial septum
What phase of the action potential is generally recorded on the electrogram?
Phase 0
What is the speed of conduction in the Purkinje fibers?
4 m/s
What resting membrane potential in a ventricular muscle cell?
-80/-90 mV
What percentage of people have the SA nodal artery arising from the RCA?
55%
