Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cardiovascular > SM 135 Bradycardia > Flashcards

SM 135 Bradycardia Flashcards

1
Q

Describe the location of the SA Node?

A

SA Node is found in the sulcus terminalis, at the junction of the SVC + R. Atrium, and is relatively epicardial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What major anatomical landmark is near the SA Node?

A

The junction of the SVC and R. Atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Does the SA Node show up on EKG and why?

A

SA Node does not show up on EKG because it is a very small group of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of the SA Node?

A

The SA Node is the natural pacemaker of the heart and sets the heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a sinus rhythm?

A

A normal heart rate set by the SA Node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What outflow(s) of the nervous system control the SA Node?

A

The SA Node and the heart rate are manipulated by Sympathetic Tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is the R. Atrium connected to the L. Atrium?

A

Via Bachmann’s Bundle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How is the SA Node connected to the AV Node?

A

Internodal tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What outflow(s) of the nervous system control the AV Node?

A

Both Sympathetic and Parasympathetic (Vagal) Tone control the AV Node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Does the AV Node show up on EKG and why?

A

The AV Node does not show up on EKG because it’s a small group of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where is the AV Node found?

A

At the junction of the R. Atrium and R. Ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does conduction change at the AV Node?

A

Conduction is delayed at the AV Node to allow the Atria to contract and the Ventricles to fill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the components of the His-Purkinje system?

A

Bundle of His, R + L Bundle Branches, Purkinje Fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe conduction in the His-P system?

A

“Highway” = rapidly conducting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does the Left Bundle Branch compare to the Right Bundle Branch?

A

Both are part of the His-P system, but the Left Bundle Branch is much larger and more branched than the Right Bundle Branch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When does the SA Node depolarize?

A

Before the P wave - not seen on EKG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When do the Atrial Myocardium and Internodal tracts depolarize?

A

During the P wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When does the AV Node depolarize?

A

During the PR interval, which represents a pause between Atrial and Ventricular contraction; before the His-P system depolarizes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When does the His-P System depolarize?

A

During the PR interval; after the AV Node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When does the Ventricular Myocardium depolarize?

A

During the QRS complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When does the Ventricular Myocardium repolarize?

A

During the T wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What heart rate represents Bradyarrhythmia?

A

Ventricular rate < 60 bpm

23
Q

What are the symptoms of Bradyarrhythmia?

A

Syncope, dizziness - may be asymptomatic

24
Q

Where along the conduction system of the heart do arrhythmia’s usually arise?

A

Usually arise in the SA and AV node

25
Q

What intrinsic pathologies underlie Sinus Node dysfunction?

A

Problems with Impulse Formation and Impulse Propagation to the AV Node, as well as age-associated fibrosis

26
Q

What does Impulse Formation in the SA Node correspond to on the Pacemaker AP?

A

Impulse propagation errors arise during Phase 4 of the Pacemaker AP

27
Q

How do Impulse Formation issues manifest in the SA Node?

A

Sinus Bradycardia, Chronotropic Incompetence, Tachy-Brady Syndrome, and Sinus Arrest

28
Q

What can cause Sinus Bradycardia?

A

Insufficient depolarization frequency

29
Q

How does Chronotropic Incompetence usually present?

A

Normal resting HR + inadequate HR response to exercise

30
Q

How does Phase 4 of the Pacemaker AP set the HR?

A

The slope of Phase 4 sets the Heart Rate, with cells higher in the SA node having sharper slopes and setting faster Heart Rates

31
Q

What extrinsic pathologies underlie sinus node syfunction?

A

Medications such as Beta blockers and Calcium channel blockers, electrolyte abnormalities, hypotension and hypothyroidism

32
Q

Why is increased Vagal tone to the SA Node usually not pathologic?

A

Increased vagal tone decreases sinus rate, but usually as a compensatory measure such as athletes with hypertrophied hearts

33
Q

What is Tachycardia-Bradycardia syndrome?

A

A burst of tachycardic activity driven by an external stimulus followed by a period of bradycardic activity due to myocardial stunning after the stimulus is removed

34
Q

What can cause a 1st degree AV block?

A

Interference at the AV Node due to scarring or high vagal stimulation

35
Q

How does a 1st degree AV block present?

A

Delayed PR interval between Atrial and Ventricular depolarization with no dropped beats

36
Q

What can cause reversible damage to the AV Node?

A

Increased Vagal Tone - can be countered with drugs

37
Q

What can cause irreversible damage to the AV Node?

A

Scar formation - cannot be healed

38
Q

What can cause a 2nd degree AV block?

A

Interference at the AV Node due to scarring or high vagal stimulation

39
Q

How does a 2nd degree Type 1 AV block present?

A

Progressively longer delays between the P wave and QRS complex with dropped beats

40
Q

How do a 1st degree and 2nd degree AV block differ?

A

2nd degree AV blocks have dropped beats and may have varying PR intervals, while 1st degree AV blocks do not drop beats and have constant PR intervals

41
Q

What can cause increased Vagal Tone?

A

Athletes and post-surgery; affect the AV Node

42
Q

How does a 2nd degree Type 2 AV block present?

A

Fixed delays between the P wave and QRS complex with dropped beats

43
Q

Which type of 2nd degree AV block requires a pacemakers?

A

Type 2 2nd degree AV block requires a pacemaker

44
Q

Which type of 2nd degree AV block is worse?

A

Type 2 is worse because it is due to damage to the conduction fibers in the His-P system, while Type 1 is often from transient increases in Vagal tone

45
Q

How do Type 1 and Type 2 2nd degree AV blocks differ?

A

Type 1 has progressive delays between the P wave an QRS complex that climax cyclically in a dropped beat while Type 2 has constant delays

46
Q

How does a 3rd degree AV block present?

A

P waves show up independent of QRS complexes

47
Q

What causes a 3rd degree AV block?

A

A total blockage in conduction from the AV Node to the Ventricles

48
Q

Does a 3rd degree AV block need a pacemaker?

A

Yes

49
Q

What types of AV blocks need a pacemaker?

A

2nd Degree Type 2 + 3rd Degree AV Blocks need pacemakers

50
Q

Why can QRS complexes form independently of P waves in a 3rd degree AV block?

A

Despite the total block between the AV Node and the Ventricles, escape pacemakers can provide autorhythmicity at relatively slower rates

51
Q

What are the escape pacemakers?

A

The Junctional Escape Rhythm and the Ventricular Escape Rhythm

52
Q

Which escape pacemaker is faster and why?

A

The Junctional Escape pacemaker is faster at 40-60bpm, while the Ventricular Escape pacemaker is slower at 20-40bpm; this is because the Junctional Escape pacemaker uses the His-P conduction system while the Ventricular Escape pacemaker relies on cell junctions

53
Q

Which escape pacemaker uses the His-P system?

A

The Junctional Escape rhythm, which results in the formation of fast and narrow QRS complexes while the Ventricular Escape pacemakers forms slow and wide QRS complexes

54
Q

How does the His-P system alter the QRS complex on EKG?

A

Signals that use the His-P system, such as Sinus rhythm and Junctional Escape Pacemaker, form narrow and fast QRS while those that don’t, such as the Ventricular Escape Pacemaker, form slow and wide QRS

Cardiovascular (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions