Module 3: ECG And Common Arrythmia Flashcards
What is the normal range for PR segments?
<200 ms
What is the normal range for the QRS complex?
<100ms
What is the 5 step method for diagnosing Rhythms?
- Heart rate
- Rhythm
- P waves
- PR intervals
- QRS complex
In the 5 step method what should we look for in terms of heart rate?
Is it normal? Normal heart rate is 60-100 bpm
In the 5 step method what should we look for in terms of rhythm?
Regular or irregular
What should we look in the 5 step method for P waves?
Is it uniform? One P per QRS
What should we look for in the 5 step method for diagnosing rhythms for PR intervals?
Is it normal? <200ms
What should we look for in terms of QRS complex in terms of the 5 step method?
Is it normal? <100ms
What is normal sinus rhythm (NSR)? (where it originates and where it goes)
Impulse is originating from the SA node and travels through the normal conduction pathway through the heart at a normal rate
What is abnormal sinus rhythm examples? 2
- Sinus bradycardia
- Sinus tachycardia
What is the range for sinus bradycardia?
<50-60 bpm
What is the range for sinus tachycardia?
> 90-100 bpm
What are bundle branch blocks?
A bundle branch block refers to signal slowing up, or being blocked at either the right or left bundle branches. remember the conduction pathway
What two examples of bundle branch blocks?
- RBBB
- LBBB
What is something that we notice about the ECG for a abnormal bundle branch block?
The impulse can now go no further
What does the RBBB look like?
Rabbit ear appearance
What is an AV block?
A disturbance in the conduction at the AV node level.
As the degree increases what happens to the AV block?
It gets worse
How many levels of AV blocks are there?
- First degree
- Second degree
- Third degree (complete/ AV dissociation)
For a second degree AV block, what are the subcategories?
- Type I Mobitz/ wenkebach
- Type II Mobitz II
What does a 1st degree AV block look like? 2
- Prolonged PR interval >200ms (1 big square)
- One P wave before each QRS
What is a 2nd degree AVB- Mobitz I (wenkenbach) look like?
Gradually lengthening PR interval until there is a dropped QRS complex
What does the 2nd degree AVB- Mobitz II look like? 2
- Normal PR interval This is the biggest distinguished
- Has P wave with no QRS following
What does the 3rd degree AV block (AV dissociation) look like (Think P waves and QRS)? What happens with the ventricles? What does this mean for the patient?
- There is no association between P waves and QRS complexes
- Ventricles are coming up with their own breathing rate
- P waves are completely unrelated to the QRS
- The patients need a pacemaker
What is the AV heart block poem =D
What are the three types of atrial arrhythmias?
- Premature atrial contractions
- Atrial flutter
- Atrial fibrillation
Which arrhythmias is the most benign?
PAC - Premature atrial contraction
What is PAC - Premature atrial contraction?
When atrial muscle tissue produces its own impulse leading to atrial contraction followed by ventricular contraction
What may premature atrial contraction (PAC) be a result of?
Too many catecholamines
During a premature atrial contraction what happens during the compensatory pause?
The timing is “reset” with the SA node taking over the rhythm again
For abnormal atrial contractions, pacemakers set the heart rate how?
Very high! At 300bpm
What does Atrial flutter look like?
AV node cannot handle this high heart rate and only lets through some of the impulses
Can a atrial flutter be regular?
Every 2nd, 3rd, 4th, etc.
For atrial flutter, what is the normal response?
1:1 when in normal sinus rhythm
What is atrial fibrillation (A- Fib) caused by?
Caused by very disorganized atrial contraction
Atria quiver rather than contract
What does A-fib look like?
- Many ectopic atrial electrical signals competing to pace the heart.
- Rhythm is very irregular
What is A-fib associated with? 2
- Atrial enlargement
- Patient will lose their “atrial kick”
What are three types of ventricular arrhythmias?
- Premature ventricular contractions
- Ventricular tachycardia
- Ventricular fibrillation
PVC - Premature ventricular contraction looks similar to what?
PAC
What may cause PVC - Premature ventricular contraction? 2
- Catecholamines, stress are the most often cause
- May also be caused by a partially blocked artery causing a zone of ischemia
What is PVC - premature ventricular contraction usually followed by?
Compensatory pause
What does the zone of ischemia look like?
It has altered ions within it which alters the impulse formation and propagation properties leading to PVC
For a PVC - Premature ventricular contraction, because QRS is early, what happens?
No preceding P wave
Is multiple PVCs significant findings?
No!
Multiple PVC can occur in what kind of intervals? 3
- 2s (couplets)
- 3s (triplets)
- 4s (quadruplets)
Wha this does Ventricular tachycardia (VT) look like)?
- Very rapid, but coordinated ventricular beats
- Re- entry loop through the ventricles only
What is Ventricular arrhythmias caused by? (conditions)
Myocardial infarctions
What is a sustained ventricular tachycardia? (Think urgency)
Medical emergency
What happens during ventricular fibrillation (VF)? 2
- Very rapid, incoordinate motion
- Ventricles cannot beat, but rather quiver
What kind of situation is Ventricular fibrillation?
Extremely emergent situation
What are some misc ECG findings? 4
- ST segment changes
- Wolff- Parkinson’s- white syndrome
- Asystole
- Bigeminy
What does ST segment depression indicate?
Myocardial ischemia
If the ST segment is elevated it indicates what?
Myocardial infarction
How do we compare the level of the ST segment?
With the PR segment
