Rpsgt: A-Step Module- Arrhythmias

Front 1

How many chambers does the heart have?

Back 1

4

Front 2

What is the purpose of the sinoatrial node (SA node)?

Back 2

1) acts as a pacemaker
2) conducts the electrical impulse through the atria
3) Depolarizes and contracts creating P-wave

Front 3

How is the path of the heart's electrical signal?

Back 3

SA node --> AV node--> Bundle of HIS --> Left and right bundle bronchis --> Purkinje fibers

Front 4

What is an arrhythmia?

Back 4

Abnormal cardiac cycle
Anything that changes electrical conduction

Front 5

What are possible causes of arrhythmias?

Back 5

1) Damage to tissues (heart attack)
2) Replacement of tissues (scarring, tumors)
3) abnormal levels of electrolytes (P, Ca, Na, Mg)
4) Drugs
5) Hypoxemia

Front 6

What is a normal heart rate?

Back 6

60-100 beats per minutes (bpm)

Front 7

What are the characteristics of a Premature Ventricular Contraction (PVC)?

Back 7

1) Single beat starts in the ventricle rather than the SA node
2) Doesn't start in atrium, no p-wave
3) Conduction time longer, QRS wide because it doesn't travel along normal pathway

Front 8

What patterns can be seen in PVCs?

Back 8

1) Couplets: 2 consecutive PVCs
2) Bigeminy: PVCs alternating with a normal heart beat
3) Trigeminy: Every 3rd beat
4) Quadrigeminy: every 4th beat

Front 9

What is a Ventricular Tachycardia (V-Tach)?

Back 9

1) 3 or more PVCs in a row
2) Heart contracting rapidly and in unorganized manner
3) Ventricles can't fill with blood to sustain normal BP

Front 10

What is Non-Sustained Ventricular Tachycardia?

Back 10

V-tach with sinus rhythm

Front 11

What is sustained V-Tach?

Back 11

No change in rhythm

Front 12

What can V-Tach degenerate quickly into?

Back 12

Ventricular fibrillation or asystole

Front 13

What is Ventricular Fibrillation?

Back 13

1) Multiple sites in ventricles initiate beats in rapid, random fashion

2) Pattern cannot sustain blood flow and quickly degenerates to asystole

3) Medical emergency

Front 14

What are Premature Atrial Contractions (PACs)?

Back 14

1) Site in atria other the SA node fires

2) Produces a P-wave earlier than expected

3) Doesn't originate from SA node

4) P-wave can be hidden in T-wave

Front 15

What are Premature Junctional Complexes?

Back 15

Premature beats in AV junction

Front 16

What do the P-waves of Premature Junctional Complexes look like?

Back 16

Inverted P before or after QRS because signal produced in AV node up into atrium and down into ventricle

Also, can be no P-wave

Front 17

What does the QRS-signal look like Premature Junctional Complex?

Back 17

The QRS is narrower

Front 18

What diseases are Premature Junctional Complexes associate with?

Back 18

heart disease and digitalis toxicity

Front 19

What is Atrial Fibrillation (A-Fib)?

Back 19

1) many sites in the atria fire at rapid rates (>300 bpm)
2) rapid and erratic atrial rhythm

Front 20

How does Atrial Fibrillation affect the atrium of the heart?

Back 20

The atrium cannot pump blood efficiently because quivering at a rapid rate.

Front 21

How does Atrial Fibrillation affect the ventricles of the heart?

Back 21

It only causes some irregular ventricle rhythms

Front 22

What are causes of Atrial Fibrillation?

Back 22

1) Heart disease of atrial conduction system
2) thyroid disease

Front 23

What are the ECG characteristics of Atrial Flutters?

Back 23

1) Rapid impulses
2) Saw tooth pattern in ECG
3) Atrial rate irregular

Front 24

What is the role of the AV node in Atrial Flutters?

Back 24

The AV node prevents the ventricles from conducting at the same rate as the flutter wave so the ventricle rate is less than the atrial rate and usually regular.

Results in rapid ventricle rate and decreased BP

Front 25

What are Atrio-Ventricular Blocks (AV-Blocks)?

Back 25

Pause in conduction at AV node is longer than usual
Delays or prevents conduction from proceeding ventricles

Front 26

How degrees of Atrio-Ventricular Blocks are there?

Back 26

3

Front 27

What are the characteristics of a Degree 1 AV-Block?

Back 27

1) Pause in AV node lengthens but each beat from atria
2) Pause lengthens so much that only some atrial signals get through, others blocked
3) P-Wave, no QRS response
4) Conduction completely blocked, atrial and ventricles beat independently

Front 28

What are the characteristics of Degree 2 AV-Blocks?

Back 28

1) P-R interval gradually increase with each wave until P fails to conduct

Front 29

In what patients are degree 2 degree AV-blocks generally found?

Back 29

Patients with Heart Disease

Front 30

What is another name for a degree 2 AV-Block?

Back 30

Mobitz Type I or Wenckebach

Front 31

What are the characteristics of a Mobitz Type II AV-Block

Back 31

1) Beats completely blocked
2) Every other beat 2 to 1 block (2 Ps:1 QRS)
3) 3 to 1 block: 3Ps:1 QRS

Front 32

What are the characteristics of a 3rd degree AV-Block?

Back 32

1) no conduction between atria and ventricles
2) site in ventricles must fire in order for ventricles to contract
3) ventricle rate is slower than rate of atrial site
4) QRS regular and wide
5) Leads to decreased BP and death