Cardiac Arrhythmia

Question 1

Mitral valve

Answer 1

AV valve/bicuspid valve - left side

Question 2

Tricuspid valve

Answer 2

AV valve - right side

Question 3

Aortic valve

Answer 3

Semilunar valve - left side

Question 4

Pulmonary valve

Answer 4

Semilunar valve right - side

Question 5

Isovolumic ventricular contraction

Answer 5

myocytes contract; all valves closed; NO filling

Question 6

Ventricular ejection

Answer 6

Blood pumped to body/lungs, SL valves open

Question 7

Isovolumic ventricular relaxation

Answer 7

all valves closed, atrial filling

Question 8

Early diastole

Answer 8

AV valves open, 80% passive filling

Question 9

Arterial systole

Answer 9

Atrial contraction, AV valves open, 20% more filling of ventricles

Question 10

Action Potential phase 0

Answer 10

rapid deploarization; influx of Na in regular cardiocytes, influx of calcium in SA/AV nodes

Question 11

Action Potential phase 1

Answer 11

transient potassium channels open, potassium efflux

Question 12

AP phase 2

Answer 12

sustained muscle contraction; calcium influx, potassium efflux

Question 13

AP phase 3

Answer 13

rapid repolarization; amplified K efflux, calcium channels closed

Question 14

AP phase 4

Answer 14

resting membrane potential; membrane is slowly depolarizing through funny channels (HCN)

Question 15

Absolute refractory period

Answer 15

Phase 0-3; impossible due to inactivation of ion channels

Question 16

Relative refractory period

Answer 16

Phase 3-4; require stronger stimulus

Question 17

Which wave (ECG) represents AP conduction from atrium to ventricle?

Answer 17

PR interval

Question 18

Which wave (ECG) represents ventricle repolarization?

Answer 18

T wave

Question 19

Which wave (ECG) represents ventricle depolarization?

Answer 19

QRS complex

Question 20

Which wave (ECG) represents atrial depolarization?

Answer 20

P wave

Question 21

The 12 lead Holter ECG has two leads, the chest and the limb. Which lead measures activity in the frontal plane?

Answer 21

Limb - I, II, III, aVR, aVL, aVF

Question 22

What are the physical causes that can result in changes in automaticity?

Answer 22

Ischemia, scarring, electrolyte disturbances, medications, advanced age - thickening of heart tissues

Question 23

Formation defect

Answer 23

Enhanced automaticity or Triggered automaticity = Disturbance in impulse formation leading to changes in automaticity

Question 24

Re-entry is a disturbance in impulse _________

Answer 24

conduction

Question 25

Enhanced automaticity

Answer 25

ectopic foci causing abnormal AP conduction, resulting in accelerated pacemaker rate = tachycardia

Question 26

EAD - early afterdepolarization

Answer 26

depolarization during phase 2 or 3 - inappropriate opening of sodium or calcium channels

Question 27

DAD - delayed afterdepolarization

Answer 27

depolarization during phase 4

Question 28

Requirements for re-entry conduction defect

Answer 28

- potential circular conduction pathway - block within a part of the circuit - delayed conduction in remainder of the circuit

Question 29

AV bundle of kent

Answer 29

accessory connection in Wolff-Parkinson-White syndrome

Question 30

Type B accessory pathway

Answer 30

through right bundle branch

Question 31

Type A accessory pathway

Answer 31

through left bundle branch

Question 32

Wolff-parkinson-white syndrome causes what type of tachycardia?

Answer 32

Re-entrant supraventricular tachycardia

Question 33

In premature ventricular contractions, the premature beat originates in the ______________

Answer 33

Purkinje fibres

Question 34

Which type of arrhythmia is caused by a single ectopic dominant reentry loop?

Answer 34

Atrial flutter

Question 35

Which type of arrhythmia has normal ventricle activities - a normal QRS at normal intervals?

Answer 35

Atrial flutter

Question 36

Which arrhythmia is characterized by a skipped heart beat?

Answer 36

Premature ventricular contraction

Question 37

What does the ECG of atrial fibrillation look like?

Answer 37

No p wave, irregular QRS

Question 38

Ventricular fibrillation ECG

Answer 38

Irregular large QRS complexes

Question 39

In ventricular fibrillation, what is happening to the ventricles?

Answer 39

Ventricular quivers - rapid, uncoordinated, inefficient contractions resulting in no cardiac output