Module 5 Flashcards
Where does a wandering atrial pacemaker originate from?
Different points in the atrial tissue
What is a key indicator that your patient has a wandering atrial pacemaker?
3 different P waves in the strip, normal QRS, QT
Is there a conduction problem with this wandering atrial pacemaker rhythm?
Not normally
What is the cause of wandering atrial pacemaker rhythm?
This dysrhythmia can be the normal parasympathetic effect of changes in intrathoracic pressure during the respiratory cycle. It can also be the result of digitalis toxicity
What are the O2 demands with a wandering atrial pacemaker rhythm?
If the heart rate goes to fast or to slow, it can cause issues such as decreased cardiac OP (hr to slow) and if to fast, decrease in ventricle filling and increase oxygen supply
What are some interventions for a wandering atrial pacemaker rhythm?
ASSESS PATIENT FIRST
Usually no problem but always assess
What is it called when the atria contracts eairler than expected?
Premature atrial contraction (PAC’s)
What is it called when another part of the heart (outside the conduction system) acts as a pacemaker?
Ectopic focus
When do PAC’s occur
When a ectopic focus fires faster than the SA node
What is the conduction problem that occurs with PAC’s?
Somewhere outside the conduction system, forms a impulse and contracts sooner than expected
What is the cause of PAC’s?
Stimulants such as alcohol, caffeine, tobacco and narcotics
Also electrolyte imbalance, heart disease and anything that increases sympathetic tone
How do PAC’s effected the O2 demands of the heart?
In a healthy individual you are fine
If the patient has a rapid pulse, this can increase the O2 demands of the heart and this can lead to a A-fib or A-flutter rhythm
What are some interventions for PAC’s
Assess patient first
?Dig levels
document findings and notify physician if you are worried or patient is symptomatic
What is the rate and rhythm of PAC’s?
Usually normal and regular
What does the P-wave look like in a PAC?
Positive and upright, before QRS complex
Premature P wave may look different
What is the length of the PR and QRS
- 12-0.20 secs
0. 10 Secs or less
What is Atrial tachycardia?
When the atrial ectopic focus takes over control of the SA node (Impulse formation)
What is the rate of atrial tachycardia?
110-250 BPM
Is the atrial and ventricular rate the same in AT?
Yes
How can you tell the difference between atrial tachycardia and sinus tachycardia?
SA node fires during Sinus tach, therefore the rate is usually under 180 BPM
If the rate is higher than 180 BPM, suspect atrial tachycardia
Can you see P waves in AT?
No, they are usually buried in the QRS complex
How do you tell if it is atrial or ventricular tachycardia?
QRS complex looks normal in AT
QRS complex in VT are bizarre and wide
What are some key factors to help you identify AT?
- fast rates
- different-looking or hidden P waves
- normal-looking QRS complexes, and
- A regular rhythm
What is the conduction problem with AT?
Site of impulse formation is the atrial tissue
What are some causes of AT?
Heart disease
Tissue hypoxia
Dig toxicity
Cor Pulmonale and respiratory failure
What does a AT rhythm do to O2 demands?
An increase in heart rate increases myocardial oxygen consumption which can lead to further myocardial ischemic and tissue damage
A rapid heart rate shortens diastolic filling time therefore, cardiac output is decreased.
Also, the coronary arteries fill during diastole.
So a shortened diastolic filling time shortens coronary artery perfusion time. This further decreases oxygen supply.
What are some interventions for AT?
Assess your patient first
Medications can be used if symptoms are mild
Cardioversion can be done in severe cases
Vagal manoeuvers used to stimulate the baroreceptors in the CA to cause trigger the vagus nerve and slow down heart rate.
Coughing, baring down and CSM can be done to stimulate the vagus nerve
What is the rate and rhythm of AT?
150-250 BPM and regular rate
P wave and PR interval?
Hard to measure and see due to being buried in the QRS complex
QRS complex?
usual 0.10 secs or less
What is Atrial flutter?
Rapid and regular rhythm due to an irritable atrial ectopic focus
What do the P-waves look like in A-flutter?
Saw tooth
What is the rate and rhythm of A-flutter?
250-350 BPM and regualr
What protects the patient from the rapid rate of firing in A-flutter?
AV junction
