ECG Arrthymias Flashcards
What are the adverse signs of arrthymia?
- Shock
- Syncope
- Heart failure
- Myocardial ischemia
- Extremes of heart rate
What is sinus bradycardia?
Where the electrical signal comes from the sino atrial node at a rate of less than 60.
What are the key 3 lead characteristics of Sinus Bradycardia?
- Rate <60
- Regular
- Normal P wave andd PR interval
- Normal QRS complex.
What are the potential causes of Sinus Bradycardia?
- Physiological
- Cardiac Origin (Sinus node disease)
- Drug induced
What is sinus tachycardia?
When the electrical signal originates from the sino-atrial node at a rate greater than 100.
What are the causes of sinus tachycardia?
- A Physiological response (Pain, fever or haemorrhage)
What does SVT indicate?
A pacemaker site that is above the ventricles but is not the SAN.
What are the likely pacemaker sites in SVT?
Atria/ Atrio-ventricular node.
What wave isn’t present in an SVT ECG?
P waves
Is SVT always constant throughout patient assessment?
- False
- SVT may be paroxysmal, Pt may have runs of SVT before returning to normal sinus.
What are the key features of an SVT rhythm?
- Rate 150-220
- Regular Rhythm
- Abnormal/ Abscent P waves
- P-R interval can’t be seen
- Normal QRS interval
What is an Atrial Tachycardia?
Ectopic atrial Rhythm that is more than100 bp,.
What is the maximum rate of SVT in infants?
300
What is the rate of SVT in Adults?
150-220
What is the pulse rate of Atrial Tachycardia?
110 - 180
What are the features of atrial tachycardia?
- 100-180
- Regular Rhythm
- Different P wave morphology, may merge into the previous T Wave
- P-R interval often in normal range
- Normal QRS.
What is a common ECG feature of Sinus Tachycardia, Supraventicular Tachycardia and Atrial Tachycardia?
- Normal QRS complex
- Rate over 100
What changes in the AV node during Atrial Tachycardia?
- It doesn’t hold the electrical impulse
What are the likely outcomes of Patients in Atrial Tachycardia?
- Hypotension
- Poor Perfusion
- Cerebral Hypoxia
Where is firing as a pacemaker during a PAC?
- the Myocites in the left atrium, not the SAN.
What are the common causes of PACS?
- Stress
- ischemia
- Atrial Enlargement
- Caffine/ Nicotine
What are the features of PACs ?
- Rate may be normal,
- irregular Rhythm
- P waves normal, but those before the PAC differ in morphology
- QRS normal
What is affected if a PT is presenting with frequent PACs?
Reduced Cardiac output.
What is a common symptom of a PT presenting with PACs?
Palpitations
What is Atrial flutter?
When the SAN is firing off at a rapid rate, but the AVN blocks them (As the ventricles can’t respond to the rapid rate of signals) and sends the impulse back across the right atrium.
What shape is given in Atrial flutter?
- Saw tooth appearance.
What are the causes of Atrial flutter?
Damage to the heart, increased sympathetic tone.
What are the features of Atrial flutter?
- Atrial rate = 300+ per minute
- No P waves
What may occur to a PT who is in Atrial flutter?
- A reduced Cardiac output
- Chest pain due to increased workload and reduced oxygenation
- increased risk of stroke.
What is Atrial Fibrillation?
When electrical impulses fire off from around the atria.
What causes the irregular ventricular rates in patients with AF?
The inconsistent conduction at the AV node.
What are the causes of AF?
- Heart disease
- Congestive heart failure
- Mitral Stenosis
- Atrial infarction
What are the features of an AF Rhythm?
- Atrial rate >360
- Irregular rhythm
- P waves not present
- No identifiable PR interval
- Normal QRS
What is Sinus Arrthymia?
- Variation in heart seen during respiratory action. The rate increases during inspiration and decreases in expiration.
What is normal during Sinus Arrthymia?
- QRS complex
- p wave presentation
- P-R interval
What is the regularity of Sinus Arrthymia?
- irregular, variable rate depending on respiration rate.
What is a Wandering Atrial pacemaker?
An irregular Rhythm created by multiple trial pacemaker sites.
How many different p-wave morphological are found in wandering atrial pacemaker rhythms?
- A Minimum of 3 different P wave
What are the common causes of Wandering Atrial pacemaker?
- Pt with an Enlarged atria
- Pulmonary disease
- Commonly benign
What is Sinus Arrest?
Where there is a pause in rhythm due to a failure of the SAN
What are the features of Sinus Arrthymia?
- Complexes normal
- Periods of no electrical activity
What are the causes of Sinus Arrthymia?
- increased Parasympathetic tone
- Digoxin Overdose
- Ischemic heart disease
When is a Delta wave formed?
- A Kent Bundle is formed and it bypasses the AVN.
- This forms a superimposed wave with the normal wave of excitation
Where is the delta wave found?
In the QR segment
What are the ECG changes associated with Wolf Parkinson White syndome?
- Delta wave
- Shortened PR intervl
- QRS complex >12
- ST-T wave changes
- Associated with Paroxysmal tachycardia
How should a Pt be treated in sinus arrest if their rate is <50?
Treated as Bradycardic
What is a junctional arrthymia?
Where the AVN becomes the natural pacemaker due to a faulty SAN.
What are the different types of junctional Arrthymia?
- High nodal
- mid nodal
- low nodal
What is a high nodal junctional arrythmia?
When the AVN fires up into the atria then down in the bundle of his. Characterised by inverted P waves.
What is a Mid-nodal junctional arrthymia?
When the AVN fires up into the atria and down into the ventricle at the same time. Characterised by a regular rhythm with P waves being hidden by the QRS.
What is a low-nodal junctional arrthymia?
Where the AVN fires down to the bundle of his and up into the atria. The P wave is inverted after the QRS.
What are the key characteristics of a junctional arrthymmia?
- Rate - 40 and 60
- Accelerated rate - 60 - 100
- P waves absent or inverted
- PR interval <0.12
What are Premature Junctional contractions (PJC)?
Ectopic beat that originate from a focus in the AVN area.
What are the characteristics of a PJC?
- Rhythm is regular except the PJC (S)
- P waves associated with the PJC will be inverted
What are the common causes of PJC?
- Drug Toxicity
- Ichemia
- Hypoxia
- Electrolyte imbalance
What are the likely outcomes of regular PJCs?
- Palpitations
- Reduced cardiac output
What are premature ventricular contractions?
When the electrical impulse originates somewhere in the ventricular myocardium
Where does a PVC normally occur?
Before the next sinus beat
What are the features of a PVC?
- Regular rhythm except the ectopic beat
- PR interval absent in the PVC
- Wide and bizarre QRS in ectopic beat
What is a Premature ventricular contraction?
An Ecptopic beat where the electrical signal originates from somewhere in the ventricular myocardium.
Where does a PVC normally occur?
Before the next sinus beat.
What are the features of a PVC?
- The main rhythm is regular except the PVC
- The P-R interval is absent in the PVC
- Wide and bizarre QRS in ectopic beat
What is a multifocal PVC?
An eptopic beat where the electrical signal originates from muliple points within the ventricular myocardium, generating different morphologies of ectopic beats.
What are the types of PVC pattern?
Couplet - 2 in succession
Salvos - 3 or more in succession
Bigeminal - Every second beat is a PVC
Trigeminal - Every third beat is a PVC
What are the common causes of PVC?
- Ischemic heart disease
- Hypoxia
- Overdose
- Increased parasympathetic/ Sympathetic activity
- Acidosis
What is a R on T ectopic?
When the R wave of the PVC is seen to be impacting on the proceeding T Wave.This is due to the ventricular depolarisation taking place before repolarisation is complete.
What may an R on T wave come before?
VF
What is an Ideoventricular rhythm?
Where the electrical rhythm originates fro within the ventricles.
What are the causes of idovetricular rhythms?
- Toxity
- MI
What rate is considered an accelerated idioventriular rhythm?
40-100
What is discordance?
When the QRS and ST-T heads in opposite directions.
What are the causes of Idioventricular Rhythm?
- Drug Toxicity
- MI
What is the QRS of Ventricular Tachycardia?
100 - 300
Where does Ventricular Tachycardia originate from?
1x Foci in the Ventricles
What are the characteristics of Ventricular Tachycardia?
- Rate > 100BPM
- Regular
- Pwaves present but buried within the QRS
- Wide and Bizarre QRS complex
What is Torsade De Points arrhythmia?
A ford of VT caused by a prolonged QT interval.
What is the clinical significance of a Torsade De points arrhythmia?
- Insuffcient time for the ventricles to refil
- May often be pulseless and lead to WF
What is Torsade De Points arrhythmia often a sign of?
Myocardial excitement due to hypoxia
What is the cause of VF?
A Large number of myocytes depolarizing with no coordination.
What is ventricular standstill?
Where the impulse isn’t transmitted from the atria to the ventricles, meaning the ventricles don’t contract.
What is Pulseless electrical activity (PEA)?
Electircal activity on an ECG that doesn’t produce a contraction.
What are the features of PEA?
- Complexes with no pulses
- Complexes may be wide and bizarre
Where are pacing spikes normally viewed?
Before the QRS