Arrhythmias

Question 1

Name the types of tachyarrhythmia.

Answer 1

Afib, SVPC, VT, VPC

Question 2

Describe the pathogenesis of Afib

Answer 2

Atrial stretch (eg CHF, endocarditis, MVDV)

Question 3

What ECG complexes are seen with ventricular disease?

Answer 3

Wide and bizarre QRS

Question 4

What ECG complexes are seen with supraventricular disease?

Answer 4

Thin QRS with no P waves (superimposed on other complex)

Question 5

What type of changes on an ECG may be seen with a lesion originating near the AV junction?

Answer 5

Negative P wave or no P wave, normal QRS complex

Question 6

What changes would be seen on an ECG with a supraventricular tachycardia?

Answer 6

Superimposition of the P wave on the previous complex (t wave, st segment or QRS complex)

Question 7

What drugs may be used in the treatment of Afib (minus those for primary disease)?

Answer 7

Dignoxin (negative chronotrope, vagomimetic - slows av conduction)
Diltiazem (negative inotrope)
Beta-blockers (negative inotrope)

Question 8

In what situation would you NOT use beta blockers?

Answer 8

In cases of uncontrolled CHF

Question 9

What changes on ECG may be seen with sinus arrhythmia?

Answer 9

Alternating periods of fast and slow rhythm (respiration), +/- irregular p wave confirguration

Question 10

What is a sinus arrhythmia?

Answer 10

Irregular sinus rhythm originating in the SAN

Question 11

What physiological factors may lead to increased vagal tone?

Answer 11

Vomiting, intubation, brachycephalic, elevated ICP, hypothermia, hypothyroidism

Question 12

What events may lead to sinus tachycardia?

Answer 12

Stress, exercise, pain

Question 13

What causes an SVPC?

Answer 13

Ectopic nodal tissue in the atria (other than SAN)

Question 14

What is wolff-parkinson-white syndrome?

Answer 14

Accessory nervous pathway creation leading to supraventricular tachycardia

Question 15

What treatment may be involved in an emergency SVT?

Answer 15

Vagal manoeuvres! Ca+ channel blockers - Diltiazem, Vermapil. Negative chronotropes - Digoxin. Beta-blockers - Esmolol

Question 16

Why do junctional premature complexes generate negative P waves?

Answer 16

Retrograde spread of electrical signal to the atria

Question 17

What does a fusion complex suggest?

Answer 17

Paroxysmal ventricular tachycardia (none constant VT)

Question 18

Define ventricular tachycardia.

Answer 18

3 or more VPCs in a row

Question 19

What underlying causes lead to ventricular ectopic rhythms?

Answer 19

Catecholamine release, CHF, myocardial ischemia, acidosis, hypokalaemia, abdominal disease, thoracic trauma

Question 20

What is the treatment of choice for ventricular tachycardia?

Answer 20

IV Lidocaine. If persistent use beta blockers such as propranolol, amiodarone, soltalol etc

Question 21

Describe the emergency treatment of ventricular tachycardia.

Answer 21

IV access and lidocaine bolus, CRI amiodarone if Lido not affective. Within 24 hours oral mexiltine, propranolol, soltalol and amiodarone

Question 22

MOA amiodarone

Answer 22

Potassium channel blockers

Question 23

What mineral imbalance may lead to atrial standstill?

Answer 23

Hyperkalaemia

Question 24

Describe the changes associated with atrial standstill seen on ECG.

Answer 24

Absent P waves, spikey T waves, mildly prolonged QRS

Question 25

Describe the pathogenesis of atrial standstill

Answer 25

Continued SAN conduction but inability of the atrial myocardium to contract

Question 26

What causes an escape rhythm?

Answer 26

Slowing down or stopping of conduction through the SAN

Question 27

What is sinus sick syndrome?

Answer 27

SAN pathology leading to long pauses between QRS complexes, junctional escape complexes and atrial fibrillation (AV junction disease)

Question 28

What treatment is advised with sinus sick syndrome?

Answer 28

Pacemaker

Question 29

Name four examples of bradyarrhythmias.

Answer 29

Sinus brady, sinus arrest, sinoventricular rhythm, AV block

Question 30

Describe 1st degree AV block

Answer 30

Prolonged p-r interval

Question 31

Describe 2nd degree AV block

Answer 31

P without a QRS every few complexes (mobitz 1) or P without a QRS every other (mobitz 2)

Question 32

Describe 3rd degree AV block

Answer 32

No communication between P waves and QRS complex

Question 33

What does an atropine test of a bradyarrhythmia suggest?

Answer 33

That the murmur is vagally mediated.