ECG - Identifying some Basic Disturbances of Rhythm Flashcards
Diagnose
IMPORTANT:What is the duration of the PR interval?
Name a disease with an irregular irregular rythem?
An irregularly irregular rhythm has no pattern at all. All of the intervals are haphazard and do not repeat, with an occasional, accidental exception. Luckily, there are only three irregularly irregular rhythms: atrial fibrillation, wandering atrial pacemaker, and multifocal atrial tachycardia.
Diagnose
Diagnose
List the 12 steps for analysing a ECG?
What does SVT, AVNRT and AVRT stand for?
Supraventricular tachycardia (supra=above)
atrioventricular nodal reentrant tachycardia (reentrant=(going round and round) pointing inwards.)
Atrioventricular reentrant tachycardia
P-R interval- P to the start of the QRS wave
What is the difference between first degree and second degree AV nodal block?
In 1st degree AV nodal block, the PR interval is prolonged but every beat from the atria reaches the ventricles
In 2nd degree AV nodal block, some of the beats from the atria DO NOT get conducted to the ventricles
Diagnose
LOOK AT LAZ NOTES
Mobitz Type 1 (Wenckebach)
Mobitz Type 1 = gradual prolongation of the PR interval culminating in a dropped beat
The PR interval gradually becomes longer, in Mobitz Type 1, until the AV node can no longer cope and then blocks the conduction completely leading to a missed QRS complex
SVT
HAS NO P WAVE
Bundle Branch Blocks
Depolarisation of the ………….. ………….. and the ………….. ………….. are seen as the QRS complex on the ECG
Therefore, a conduction block of the ………….. …………..would be reflected as a change in the QRS complex
If there is a block in the right bundle branch, you get conduction going down one of the bundle branches and then spreading slowly across the myocardium
With a right bundle branch block, the left side would depolarise normally but the right side depolarises ………….. as the depolarisation has to spread slowly form the left side to the right side
With bundle branch blocks you will see TWO ECG CHANGES:
QRS complex ………….. (>0.12s)
QRS ………….. ………….. (varies depending on the ECG lead, and if it is right or left bundle branch block)
You would look at the chest leads to identify this
The QRS complex is time taken for all ………….. ………….. to be depolarised
So if one bundle branch is blocked, the depolarisation comes down and slowly depolarises across the ventricular myocardium so the time taken for all ventricular myocytes to depolarise is greatly ………….. giving a wide QRS complex
Bundle Branch Blocks
Depolarisation of the bundle branches and the purkinje fibres are seen as the QRS complex on the ECG
Therefore, a conduction block of the Bundle Branches would be reflected as a change in the QRS complex
If there is a block in the right bundle branch, you get conduction going down one of the bundle branches and then spreading slowly across the myocardium
With a right bundle branch block, the left side would depolarise normally but the right side depolarises slowly as the depolarisation has to spread slowly form the left side to the right side
With bundle branch blocks you will see TWO ECG CHANGES:
QRS complex widens (>0.12s)
QRS morphology changes (varies depending on the ECG lead, and if it is right or left bundle branch block)
You would look at the chest leads to identify this
The QRS complex is time taken for all ventricular myocytes to be depolarised
So if one bundle branch is blocked, the depolarisation comes down and slowly depolarises across the ventricular myocardium so the time taken for all ventricular myocytes to depolarise is greatly increased giving a wide QRS complex
Atrial Fibrilation
P waves ………….; oscillating baseline f (fibrillation) waves
- Atrial rate 350600 beats/min
- Irregular ………….. rhythm
- Ventricular rate 100180 beats/min
Atrial Fibrilation
P waves absent; oscillating baseline f (fibrillation) waves
- Atrial rate 350600 beats/min
- Irregular ventricular rhythm
- Ventricular rate 100180 beats/min
Sinus Tachycardia
- P waves have ………….. morphology
- Atrial rate 100200 beats/min
- ……………. ventricular rhythm
- Ventricular rate 100200 beats/min
- One P wave ……………… every QRS complex
- Often ………………… response
–Hypovolaemia, sepsis, stress, etc.
- P waves have normal morphology
- Atrial rate 100200 beats/min
- Regular ventricular rhythm
- Ventricular rate 100200 beats/min
- One P wave precedes every QRS complex
- Often physiological response
–Hypovolaemia, sepsis, stress, etc.
Bundle Branch Block
Why does the QRS complex widen?
State the Normal ECG values for the following?
Diagnose
1st degree AV block
1 to 1 relationship
long PR interval