Sinus Arrthymias

Question 1

Describe what sinus rhythm is

Answer 1

a rhythm originating from the SA node that has one positive (upright) P wave before each QRS complex-> considered normal electrical activity

Question 2

impulse originates in the __ ___ and follows normal pathways of conduction, resulting in ____ and ____ depolarization

Answer 2

SA node, atrial, ventricular

Question 3

ECG characteristics (normal sinus rhythm)
Rate:
Rhythm:
P wave:
PR interval:
QRS duration:

Answer 3

rate- 60-100 beaths/min
Rhythm- regular
P waves- uniform in appearance, positive (upright) in lead II, one precedes each QRS complex
PR interval- 0.12-0.2 second and constant
QRS- 0.10 seconds or less

Question 4

What is the rhythm termed when the SA node discharges fewer than 60 beats/min?

Answer 4

sinus bradycardia

Question 5

What is this showing?

Answer 5

sinus rhythm (normal rhythm)

Question 6

What is this showing?

Answer 6

sinus bradycardia

Question 7

What is the most common dysrhythmia associated with acute MI and where is it usually located?

Answer 7

sinus bradycardia, inferior and posterior infarction

Question 8

What term describes when the SA node discharges at a rate greater than 100 times/min?

Answer 8

sinus tachycardia

Question 9

What is this showing?

Answer 9

Sinus tachycardia

Question 10

What is the clinical significance of sinus tachycardia?

Answer 10

in the setting of acute MI, sinus tachycardia is a warning signal for heart failure, hypovolemia, and increased risk for serious dysrhythmias

Question 11

What can be used to help treat sinus tachycardia?

Answer 11

beta blockers to help slow down HR

Question 12

_____ ______ occurs when the SA node discharges irregularly

Answer 12

sinus arrhythmia

Question 13

What is this showing?

Answer 13

sinus arrhythmia

Question 14

What are the two main types of sinus arrhythmias and what are their main causes?

Answer 14

Respiratory and non respiratory, respiratory seen with changes in intrathoracic pressure and more common in children and infants,
non seen in older people with heart disease commonly after acute inferior wall MI

Question 15

T/F, a SA block happens when the SA node is unable to fire

Answer 15

false, SA node can fire but is its impulse is blocked as it exits the SA node

Question 16

What is this showing?

Answer 16

SA block

Question 17

What term is when sinus impulses are NOT generated by the SA node and AV junction or ventricles must assume pacing responsibility and results in absent PQRST complexes?

Answer 17

sinus arrest

Question 18

What is this showing?

Answer 18

sinus arrest

Question 19

What rhythm change would you see in a SA block?

Answer 19

irregular and the pause is the same as the distance between two other P-P intervals

Question 20

What rhythm change would you see in a sinus arrest?

Answer 20

irregular, the pause is of undetermined length (more than one PQRST complex omitted) and is not the same distance as other P-P intervals