ECG - Interpretation ARRYTHMIA THEORY 1 Flashcards
(35 cards)
Normal Sinus rhythm
– Intrinsic rate of 60 to 100 beats/minute
– Regular, with minimal variation between R-R intervals
– P wave is present, upright, and precedes each QRS
complex.
- Normal PR interval; 3-5 small squares/ 0.04s - 0.12s
Sinus Bradycardia
SINO ATRIAL (SA Node) Dysrhythmia
– Rate of less than 60 beats/minute
– Rhythm is regular.
– Treatment focuses on the patient’s tolerance to the bradycardia
Sinus Tachycardia
SINO ATRIAL (SA Node) Dysrhythmia
- rate of > 100bpm
- rhythm is regular
- increases the work of the heart
- treatment is related to the underlying cause
HOW TO SPOT SINUS TACHYCARDIA ON AN ECG:
- rhythm is regular with a rate of 100-160bpm
- P WAVE is NORMAL
- PR INTERVAL is NORMAL
- QRS COMPLEX DURATION is NORMAL
- BPM IS FAST
Sinus Arrhythmia
SINO ATRIAL (SA Node) Dysrhythmia
- Slight variation of a sinus rhythm
- bainbridge reflex; a cardiovascular reflex that increases the heart rate in response to increased stretching of the right atrium and/or inferior vena cava.
- Increases SV and Blood pressure
- findings are normal in children and young adults.
How to spot Sinus Arrythmia on an ECG?
Look for variation in the time in between consecutive P waves (P-P interval)
P-P interval:
This signifies the time taken for a full cycle of the heart beating takes to occur. If P-P interval is irregular, Sinus Arrhythmia could be indicated.
Also look for difference in time between each QRS complex, irregular differences indicate sinus arrhythmia.
Sinus Arrest
SINO ATRIAL (SA Node) Dysrhythmia
- SA node fails to initiate an impulse
- SA node then resumes normal functioning
- occasional episodes of sinus arrest are insignificant
- TREATMENT: based on the overall HR and tolerance to sinus arrest; are they symptomatic, displaying red flags etc.
How to spot Sinus Arrest on an ECG?
- look for a missing beat (PQRST cycle)
- rest of the rhythm will usually be regular
Premature Atrial Complex (PAC)
ATRIAL DYSRHYTHMIA
- Existence of a particular complex within another rhythm
- AKA: also know as atrial ectopic
- Occurs earlier in time than the next expected sinus complex
- TREATMENT: not usually indicated
How to spot Premature Atrial Complex (PAC) on an ECG?
-PREMATURE and ABNORMALLY shaped P wave on the PAC
- Rhythm is irregular when a PAC occurs
- underlying rhythm is regular
Supraventricular Tachycardia (SVT)
ATRIAL DYSRHYTHMIA
- occurs in the Pacemaker site above the ventricles (AV)
- HR generally above 150bpm
- TREATMENT: medication or electrical cardioversion or pacing
How to spot Supraventricular Tachycardia (SVT) on an ECG?
- The P WAVE is LOST in the preceding (before) T WAVE due to the fast heart rate
- the rhythm is regular
Atrial Flutter
ATRIAL DYSRHYTHMIA
- Atria contract at a rate too rapid for the ventricles to match
- known as a flutter (F WAVES)
- can have variable ratio of F wave:QRS COMPLEX —> (1:1 , 2:1 , 3:1 etc)
- can be regular or irregular
-TREATMENT: medication or electrical Cardioversion
How to spot Atrial Flutter on an ECG?
- VENTRICULAR rate is LESS than ATRIAL rate
- look out for SAW TOOTH flutter waves
Atrial Fibrillation
ATRIAL DYSRHYTHMIA
- Rhythm in which the atrial fibrillation or quiver, WITHOUT organised contraction
- Cells depolarise independently
How to spot Atrial Fibrillation on an ECG?
- the P WAVE is replaced by ERRATIC FIBRILLATORY WAVES.
- IRREGULARLY- IRREGULAR rhythm.
Junctional AV Rhythm
JUNCTIONAL RHYTHM
- AKA: junctional “escape rhythm”
- allows the heart to “escape” from stopping completely
- regular rate of 40-60bpm
- OCCURS when AV node or the bundle of his take over as the hearts pacemaker, instead of the SA node, often caused by SA Node dysfunction.
TREATMENT: pacemaker
How to spot Junctional AV Rhythm on an ECG?
- P waves are absent or inverted, before or after the QRS
- QRST is normal
Accelerated Junctional Rhythm
JUNCTIONAL RHYTHM
- Junctional Rhythm with a rate exceeding the normal range of 60bpm
- less than 100bpm
- P waves absent , inverted or after QRS complex
How to spot accelerate Junctional rhythm on an ECG?
- P waves are absent or inverted, before or after the QRS
- regular BPM of 60-100
- ESSENTIALLY SAME AS JUNCTIONAL (AV) RHYTHM BUT HEART RATE IS WITHIN NORMAL PARAMETERS
First Degree Heart block?
- every impulse (PRI) is delayed by more than 0.20seconds (5 small boxes
Least serious heart block
First indication of damage to the AV node
Second Degree Heart Block: Mobitz Type 1
- look for gradually increasing PRI and eventually a dropped beat (missed beat)
- BPM between 60-100
Second Degree Heart block : mobitz type 2?
- PRI is consistent
- Rhythm is regular except for dropped beats
Third Degree (complete) Heart Block
- REGULAR ATRIAL RHYTHM - observed in P waves
- Regular ventricular rhythm - observed in T waves
- P waves without QRS complexes
- BRADYCARDIA
- most serious heart bock and patient needs emergency care. In third degree heart block, the AV node disassociates completely, causing the ventricles to develop their own pace maker.
Idioventricular Rhythm
VENTRICULAR RHYTHM:
- Ventricles begin to originate their own impulses , taking over as the hearts pacemaker.
- This is usually caused by a dysfunctional, or suppressed SA node.
- causes slow heart rate - 20-50bpm
- Pulse may or may not be palpable
TREATMENT: aiming to improve Cardiac Output
