Brainscape's Knowledge GenomeTM

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


See full index

ECG Mod 1 > Module 1 Rhythms (lect 4-6) > Flashcards

Module 1 Rhythms (lect 4-6) Flashcards

1
Q

Checklist for analyzing rhythm of an ECG

A

1) P before each QRS
2) QRS after each P
3) PR intervals (for AV blocks)
4) QRS interval (for bundle branch blocks)

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

Arrhythmia vs. dysrhythmia (is there a difference?)

A

Interchangeable words; both denote an Abnormal rhythm therefore, no difference

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

Sinus Arrhythmia

A

NORMAL!!!!!!

Barely detectable rate changes in sinus pacing in relation to the phases of respirations

NOT A TRUE ARRHYTHMIA

INCREASE in heart rate during INSPIRATION

DECREASE in heart rate during EXPIRATION

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

Define Automaticity

A

Ability to inherently generate a regular cadence of depolarization

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

What are the 3 levels of automaticity and what is the purpose?

A
  1. Atrial Foci & Junctional Foci (adrenaline, increased sympathetic, cocaine, caffeine and amphetamines, hyperthyroidism, low O2)
  2. Ventricular Foci (low oxygen; low potassium, ischemia, cocaine)

Purpose: back-up pacemakers in case the SA node fails

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

What are the rates (BPM) for the difference levels of automaticity?

A
  1. Atrial Foci = 60-80 BPM
  2. Junctional Foci = 40-60 BPM
  3. Ventricular Foci = 20-40 BPM

***should the highest pace-making center fail, an automaticity focus from the next highest level emerges or “escapes” to start pacing

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

What are the three Irregular Rhythms?

A
  1. Wandering Pacemaker
  2. Multifocal Atrial Tachycardia
  3. Atrial Fibrillation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Criteria for Wandering (Atrial) Pacemaker

A

P’ (p-prime) wave represents atrial depolarization by an automaticity focus

  1. Heart rate is below 100 BPM
  2. Is a Multifocal Atrial rhythm (originating from the atria)
  3. It will have at least 3 different P-wave morphological
  4. The pacemaker site shifts between the SA node, Atria and AV node
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Underlying etiology for Wandering Atrial Pacemaker

A

Irregular rhythm produced by the pacemaker activity wandering from the SA Node to nearby atrial automaticity foci.

Caused by vagal tone (effect produced on the heart when only the parasympathetic nerve fibers (carried by the vagus nerve) are controlling the heart rate

Can also be caused by COPD. If the heart becomes tachycardia, then WAP will become MAT.

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

Criteria for Multifocal Atrial Tachycardia (MAT)

A
  1. SA node is not pacing the heart
  2. Several groups of excitable cells in the atria compete to pace the heart
  3. MAT has at least three or more different shaped P-waves
  4. MAT is an irregular rhythm above 100 BPM
  5. MAT has irregular P-R, R-R, and P-P intervals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Underlying etiology for Multifocal Atrial Tachycardia

A

Underlying “sick” heart which develops resistance to overdrive suppression leading to all Foci to pace together = atrial rate > 100 bpm

MAT is common with underlying chronic obstructive pulmonary disease (COPD) which strains the heart

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

Criteria for Atrial Fibrillation

A

Continuous rapid-firing of multiple atrial automaticity foci (CHAOS) - looks like speed bumps between each QRS complex

Irregular QRS rhythm
RAPID pacing of an unhealthy heart
Irritable atrial foci

No discernable P waves because the atria fail to depolarize completely

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

Underlying etiology for Atrial Fibrillation

A

NOT an arrhythmia of healthy, young individuals. IT is the result of multiple “irritable”atrial foci, suffering from entrance block, pacing rapidly. These multiple atrial foci are parasystolic, so they’re all insensitive to overdrive suppression; therefore, they all pace at once

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

What does ESCAPE describe?

A

Response of an automaticity focus to a pause in the pace-making activity

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

Describe Escape Rhythm and what are the three types?

A

A pause in SA node pacing permits an automaticity focus to ESCAPE overdrive suppression

  1. Atrial Escape Rhythm
  2. Junctional Escape Rhythm
  3. Ventricular Escape Rhythm

This occurs when the SA node stops pacing entirely

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

Describe Escape Contraction and what are the three types?

A

An automaticity focus transiently escapes overdrive suppression to emit one beat.

  1. Atrial Escape Contraction
  2. Junctional Escape Contraction
  3. Ventricular Escape Contraction

This occurs when the SA node stops pacing briefly (only one cycle missed)

Contraction = one beat 
Rhythm = longer period
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Discuss Sinus Arrest

A

Occurs when a “sick” SA node stops pace-making completely

The automaticity foci provide “backup” pacing

Extremely long pause between R-R with a BPM less than 50

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

Describe Escape Rhythm and what are the three types?

A

An automaticity focus escapes overdrive suppression to pace at its inherent rate.

  1. Atrial Escape Rhythm
  2. Junctional Escape Rhythm
  3. Ventricular Escape Rhythm

This occurs when the SA node stops pacing entirely

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

Atrial Escape Rhythm

A

A cardiac dysrhythmia occurring when sustained suppression of sinus impulse formation causes other atrial foci to act as cardiac pacemakers. Rate = 60-80 BPM, p wave of atrial escape has abnormal axis and different from the p wave in the sinus beat. However, QRS complexes look exactly the same

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

Junctional Escape Rhythm

A

Depolarization initiated in the atrioventricular junction when one or more impulses from the sinus node are ineffective or nonexistent.

Rate: 40-60 BPM

Irregular rhythm in single junctional escape complex; regular in junctional escape rhythm

P waves: depends on the site of the ectropic focus. They may be inverted and may appear before or after the QRS complex or they may be absent, hidden by the QRS. QRS is usually normal

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

Idioventricular (Escape) Rhythm

A

When the ventricles are not stimulated, the automaticity center escapes overdrive suppression to become a ventricular pacemaker

Rate: 20-40 BPM (almost not compatible for life)

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

Most common mechanism of action for ventricular escape rhythm

A

Complete conduction block high in the ventricular conduction system below the AV node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Rare mechanism of action for ventricular escape rhythm

A

Failure of the SA node to fire and the atria to fire (everything is shutting down)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Atrial Escape Contraction

A

A transient sinus block (SA node misses ONE CYCLE)

Atrial automaticity takes over (or escapes overdrive suppression) and emits a beat

P’ wave differed from P waves generated by the SA node

Looking for a long pause, then a jacked up P’ wave, and then back to normal contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Junctional Escape Contraction

A

If both the SA node and atrial foci fail to pace one cycle, a junctional automaticity focus will escape overdrive suppression

Normal ventricular conduction: normal QRS Complex

After one beat, the SA node takes over as the dominant pacemaker and suppresses the junctional focus

A single junctional escape beat may produce a retrograde atrial depolarization that records as an INVERTED P’ wave either before or after the QRS complex

26
Q

Ventricular Escape Contraction

A

A ventricular automaticity focus takes over as pacemaker

Produces a LARGE QRS complex

27
Q

Premature Contractions

A

An irritable focus spontaneously fires a single stimulus. Produces a contraction (depolarization) earlier than expected in the rhythm

28
Q

Premature Atrial Contraction

A

Originates in an irritable atrial automaticity focus; P’ wave earlier than expected. P’ wave looks different than the sinus-produced P wave

29
Q

How does Reset Pacing work?

A

Resetting allows the dominant pacing stimulus to generate another contraction one cycle length from the premature contraction

Resetting occurs when the dominant center of automaticity (SA node) is depolarized by the premature contraction

30
Q

How does reset pacing not reset?

A

The depolarization from the premature contraction does not reach the dominant pacing center

31
Q

What resets a premature contraction?

A

A center of automaticity resets the rhythm when it is depolarized by a premature contraction

32
Q

Atrial Bigeminy

A

When an irritable automaticity focus fires a premature atrial contraction (P’) that couples to the end of a normal cycle and repeats

33
Q

Define Couplet

A

The cycle containing the premature contraction + normal cycle

34
Q

Atrial Trigeminy

A

When an irritable atrial focus prematurely fires after 2 normal cycles and the couplet repeats continuously

Premature - normal - normal - premature - normal - normal….

35
Q

Premature Junctional Contraction

A

Occurs when an irritable automaticity focus in the AV junction suddenly fires a premature stimulus that conducts to and depolarized the ventricles

AV node prematurely stimulates the ventricles
AV node=AV junction=junctional contraction

T wave into QRS (no P wave)

36
Q

Junctional Bigeminy

A

An irritable focus in the AV node initiating a premature junctional contraction after each normal cycle

May note inverted (retrograde) P’ waves with every premature junctional contraction

37
Q

Junctional Trigeminy

A

When a premature junctional contraction is coupled with 2 consecutive, normal cycles in a repeating series of couplets

38
Q

Premature Ventricular Contraction (PVC)

A

Originates in an irritable ventricular automaticity focus

Produces a LARGE QRS complex

LARGE QRS followed by a COMPENSATORY PAUSE

39
Q

Define PVC Compensatory Pause

A

NOT caused by resetting of the SA node

The SA node depolarized but the ventricles are still refractory from the PVC

This results in a pause as the ventricles finish repolarizing

40
Q

Ventricular Bigeminy

A

When a PVC becomes coupled to a normal cycle and the pattern continues with every cycle in succession

41
Q

Ventricular Trigeminy

A

A repetitive pattern of a PVC coupling with every 2 normal cycles

42
Q

Runs of PVCs

A

Occurs when an irritable ventricular automaticity focus fires a rapid series of impulses

DANGER: a run of 3 or more PVCs in rapid succession = Ventricular Tachycardia (VT)

Low serum potassium, poorly oxygenated blood

43
Q

Multifocal PVCs

A

PVCs produced by multiple, irritable ventricular foci

Leads to QRS complexes that appear DIFFERENT since each foci produces its own unique PVC

44
Q

Tachyarrythmia

A

Rapid rhythm originating in irritable automaticity foci

Sometimes more than one active focus is generating pacing stimuli at once

45
Q

Tachyarrythmia Rates

A
  1. Tachycardia (not sinus; atrial, junctional or ventricular) = 150-250 BPM
  2. Flutter = 250-350 BPM
  3. Fibrillation = 350-450 BPM
46
Q

Paroxysmal Tachycardia (3 types)

A

Atrial, Junctional and Ventricular Tachycardias

An irritable focus SUDDENLY paces rapidly

47
Q

How does sinus tachycardia differ from paroxysmal tachycardia?

A

Gradual Response or NO automaticity focus

48
Q

Atrial Tachycardia

A

Caused by sudden, rapid firing of irritable atrial automaticity focus

Rage: 150-250 BPM

Overdrive suppresses the SA node and all other automaticity foci

P’ waves do NOT look like P waves

(He said it won’t be on the exam but who the fuck knows the truth)

49
Q

Junctional Tachycardia

A

Caused by the sudden rapid pacing of an irritable automaticity focus in the AV junction

Rate: 150-250 BPM

AV node hyperstimulation

50
Q

AV Nodal Reentry Tachycardia (AVNRT)

A

A type of junctional tachycardia

A theoretical “re-entry circuit” continuously circles through the AV node depolarizing the atria and ventricles

51
Q

Supraventricular Tachycardia (SVT)

A

Atrial Tachycardia OR Junctional Tachycardia

Both originate above the ventricles (supraventricular)

52
Q

Ventricular Tachycardia (absolutely must be able to identify this)

A

Produced by an irritable ventricular automaticity focus

Rate: 150-250 BPM

LARGE, consecutive PVC-like complexes

Caused by coronary disease or infarction;

53
Q

How does Ventricular Tachycardia work?

A

One of the regular atrial depolarizations (from the SA node) finds the AV node receptive to depolarization

The AV node subsequently depolarized the ventricles via the ventricular conduction system

This leads to normal QRS complexes in the midst of large QRS complexes produced by the irritable ventricular automaticity focus

54
Q

Torsades de Pointes

A

A form of ventricular tachycardia

POLYMORPHIC (many shapes) QRS complexes

Rate: 250-350 BPM

“Twisting of Points”; two competitive irritable foci in different ventricle areas

Caused by low potassium or medications that block potassium channels

55
Q

Atrial Flutter

A

An irritable atrial automaticity focus produces a rapid series of atrial depolarizations

Rate: 250-350 BPM

“FLUTTER” waves describe as “SAW TOOTH”

Because the AV node takes long time to repolarize, only a few atrial depolarizations reach the ventricles = MANY more P waves than QRS complexes

56
Q

Ventricular Flutter

A

Caused by a highly variable irritable ventricular focus; coronary arteries are not receiving blood flow. Leads to ventricle Fibrillation

Rate: 250-350 BPM

QRS look smooth and have a SINE-WAVE pattern

QRS are of similar amplitude

57
Q

Define Fibrillation

A

Caused by rapid discharges from numerous irritable automaticity foci in the atria or ventricles

Erratic and uncoordinated rhythm; Waves are not distinguishable

Rates are difficult to determine and the “range” is 350-450 BPM

58
Q

Atrial Fibrillation

A

Caused by many irritable atrial foci firing rapidly

Produces rapid, erratic atrial rhythm

Rate range 350-450 BPM

Only a small portion of the atria is depolarized by any one discharge which leads to few depolarizations leading to the AV node

AV node does not receive many depolarizations which means there are few ventricular depolarizations = NO discernable P waves AND IRREGULARLY IRREGULAR ventricular rhythm

59
Q

Ventricular Fibrillation

A

Due to numerous ventricular foci pacing rapidly causing an erratic twitching of the ventricles

Numerous ventricular foci firing leads to ineffective twitching of the ventricles

DANGER: ERRATIC, NO IDENTIFIABLE WAVES

350-450

60
Q

Wolf-Parkinson-White Pattern

A

An abnormal, accessory (extra) AV conduction pathway called the bundle of Kent

“Short circuits” the delay of ventricular conduction in the AV node

Leading to premature depolarization of the ventricles just before normal AV node-induced ventricular depolarization begins

Pre-excitation syndrome. Ventricles are stimulated before (pre) normal depolarization

61
Q

Criteria for Wolff-Parkinson-White Pattern

A

SHORTENED PR interval indicates pre-excitation (ventricles start contracting sooner because of the extra pathway)

DELTA WAVE also indicating earlier ventricular contraction

WIDENED QRS complex

INVERTED T wave because of different focus of depolarization from the accessory pathway

ECG Mod 1 (2 decks)

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