SA Node Arrhythmias

Question 1

Normal Sinus Rhythm

Answer 1

PR intervals duration 0.12 - 0.20 seconds QRS complexes duration 0.06 - 0.10 seconds 60-100bpm

Question 2

Sinus Brady

Answer 2

Normal PR interval & QRS complex duration Distance btwn QRS complex wide <60 bpm

Question 3

Sinus Tachy

Answer 3

Normal PR interval & QRS complex duration

Distance btwn QRS complex short

Question 4

Sinus Arrhythmia

Answer 4

Variation in rate/rhythm of heart

Rate increases during inspiration & decreases during expiration

Question 5

Sinus Arrhythmia on ECG

Answer 5

Distance bwtn P waves increases

SA node discharges irregularly

Question 6

Sinus Pause (Sinus Arrest)

Answer 6

SA node fails to generate impulse Caused by heart disease, beta blockers, ca channel blockers sx: dizziness, palpitations

Question 7

Sinoatrial (SA) Block

Answer 7

Electrical impulse gets delayed or blocked = delayed depolarization of atria Caused by irregular functioning of SA node Caused by digoxin, beta blockers, ca channel blockers Expect significant drop in cardiac output

Question 8

SA Block on Tracing

Answer 8

Dropped beats occurring after a cycle