Sinus Rhythms

Question 1

Name Sinus Rhythm Types

Answer 1

• Normal Sinus Rhythm
• Sinus Bradycardia
• Sinus Tachycardia
• Sinus Dysrhythmia (Arrhythmia)
• Sinus Arrest
• Sinus Exit Block

Question 2

Describe : Sinus Bradycardia (2)

Answer 2

• With Sinus Bradycardia the locus of stimulation is the same as normal sinus rhythm
• Just now the rate will be less than 60 bpm.

Question 3

What happens to P and T wave in sinus tachy ? (4)

Answer 3

• An additional challenge that will present as rhythm rates accelerate is that the cardiac complexes will come closer together.
• This can result in the P wave becoming partially or completely buried within the T wave of the previous cardiac complex.
• The result of a partially buried P waves means you are unable to establish the beginning of atrial depolarization. Meaning you will be unable to measure and report the PR interval.
• The only way it will be possible is if the physician instructs you to increase the machine printing speed (remember interval times will double at 50 mm/sec).

Question 4

Describe : Sinus Dysrhythmia (4)

Answer 4

• often occurs as a normal variant.
• It is commonly seen in young healthy people and athletes.
• It is frequently related to breathing and pressure on the vagus nerve. As the patient inhales and the lungs expand, pressure is applied to the vagus nerve which causes a parasympathetic response and a decrease in heart rate.
• may also occur as a result of medication effects or diseases such as multiple sclerosis.

Question 5

Describe tx : Sinus Dysrhythmia (2)

Answer 5

• Often requires no treatment
• but may require medication or therapy such as a pacemaker to regulate the heart rate if the ventricular response becomes too slow.

Question 6

Describe EKG of Sinus Dysrhythmia ()

Answer 6

• Closely resembles Normal Sinus Rhythm with the only distinction being the intervals from one cardiac complex to the next are changing as influenced by the patients respiratory pattern.
• = Changing R to R Intervals.

Question 7

Describe : Sinus Arrest (3)

Answer 7

• Sinus Arrest occurs when there is a sudden absence of electrical activity initiated by the SA node. This results in a pause in the electrical activity seen on the tracing. Remember, no electrical activity = no depolarization and contraction. Hence, a drop in blood pressure.
• The longer the pause, the further the blood pressure will drop.
• A pause of 6-seconds is considered a medical emergency and emergency procedures must be initiated.

Question 8

The ECG sinus arrest rhythm typically will demonstrate what ?

Answer 8

constant R to R intervals prior to and following the pause.
This pause results in the rhythm tracing presenting as irregular.

Question 9

Describe : Sinus Exit Block

Answer 9

• Sinus Exit Block looks very much the same as Sinus Arrest with one important distinction.
• The duration of the pause with Sinus Exit Block is in a direct multiple of the R to R interval of the underlying rhythm. Sinus Arrest does not have this specific feature.