Arrhythmias

Question 1

Right atrial enlargement

Answer 1

large P wave amplitudes

Question 2

Left atrial enlargement

Answer 2

large P wave durations, notching of P wave often seen due to out-of-sync conduction of right and left atria

Question 3

2 Main causes of QRS Issues

Answer 3

1. excessive generation of electrical potential in a particular direction, 2. more time required for depolarization wave to travel through muscle (ventricular enlargement)

Question 4

Right ventricular enlargement

Answer 4

large S waves in I, II, aVF

Question 5

Left ventricular enlargement

Answer 5

not always observed because left ventricle is already larger than right ventricle

Question 6

Intraventricular conduction defects

Answer 6

impulses aren’t as fast, QRS duration will be longer

Question 7

Left bundle branch block

Answer 7

wide and positive deflections in I, II, III, aVF, and inverted aVR and aVL, large R waves

Question 8

Right bundle branch block

Answer 8

right axis deviation usually present, large S waves in I, II, III, aVF

Question 9

Causes of arrhythmias

Answer 9

1. abnormal rhythmicity of the pacemaker
2. shift of pacemaker activity
3. conduction blocks
4. abnormal pathways of impulse transmission
5. spontaneous generation of abnormal impulses

Question 10

Sinus arrhythmia

Answer 10

impulses originate at the SA node at a varying rate, faster then slower, primary cause is respiration

Question 11

Wandering atrial pacemaker

Answer 11

impulses originate from varying points in atria, P wave changes configuration, originate from various parts of atria, QRS still normal

Question 12

Sinus arrest

Answer 12

SA node stops firing, escape beat

Question 13

First degree AV block

Answer 13

not dangerous but will progress, PR interval is very long

Question 14

Second degree AV block

Answer 14

Mobitz Type I- progressive lengthening of PR interval before dropped beat, block gets thicker, so PR interval length increases
Mobitz Type II- sudden QRS dropped without prior PR lengthening, atrial rate is greater than the ventricular rate (more P waves)

Question 15

Third degree AV block

Answer 15

QRS rate is greater than the P rate (slower), SA node paces atria, Purkinje fibesr pace ventricular (separate rates), P and T waves are biphasic, ** no relationship between the two rates

Question 16

Atrial flutter

Answer 16

atria contracting quickly

Question 17

Atrial fibrillation

Answer 17

no distinct P waves, irregularly spaced QRS complexes, no coordinated direction, AV node drives, no the SA node

Question 18

Ventricular paroxysmal tachycardia

Answer 18

runs of 3 or more VPCs in sequence

Question 19

Ventricular bigeminy

Answer 19

normal—->premature—->normal—->premature

Question 20

Ventricular fibrillation

Answer 20

cardiac output is 0, no QRS waves, decrease in velocity, shortening refractory period, most vulnerable during ventricular repolarization

Question 21

Supraventricular premature contraction

Answer 21

premature beats, P occurs before T wave

Question 22

Supraventricular paroxysmal tachycardia

Answer 22

clusters of premature contractions

Question 23

Ventricular premature contraction

Answer 23

usually no P wave, QRS wide and bizarre, morphology of QRS will vary with each focus