Natalie Ecg Quiz Flashcards
What type of complex is indicated by the arrows?
PAC
Notes:
- PACs occur when another region of the ATRIA depolarizers BEFORE the SA node and thus triggers a premature heartbeat.
- cause is unknown but occurs in healthy young adult and elder without heart disease
- abnormal shaped P waves different from NSR
- narrow QRS
Interpret the rhythm
A-flutter
Notes:
- assess Lewis Lead (S5-Lead) - RA is moved to manubrium adjacent to sternum; LA moved to R-5th ICS…read in lead 1
- type I (common) 240-340/min; counterclockwise inverted in lead II, III, aVF
- type II - follows a different re-entry pathway and faster 340-440/min. Left atrial flutter is common after incomplete left atrial ablation procedure
Interpret the rhythm
A-fib
Interpret
Accelerated Junctional Rhythm
Notes:
-no P wave (40-60)
- regular rhythm > 60 bpm
- QRS complex is narrow
Interpret
Sinus Tachycardia
This ECG demonstrates which of the following pathologies?
LBBB
Interpret the rhythm
2nd degree type 2
Interpret the rhythm
Sinus Bradycardia
Interpret the Rhythm
WPW
Interpret the Rhythm
2nd degree Type 1
Interpret the Rhythm
1st degree AV Block
Interpret the Rhythm
NSR
Interpret the Rhythm
RBBB
Interpret the Rhythm
Sinus Pause
Notes:
ECG abnormalities can be variable and intermittent. Multiple ECG abnormalities can be seen in sinus node dysfunction including:
Sinus Bradycardia.
Sinus Arrhythmia — associated with sinus node dysfunction in the elderly in the absence of respiratory pattern association.
Sinoatrial Exit Block.
Sinus Arrest — pause > 3 seconds.
Atrial fibrillation with slow ventricular response.
Bradycardia – tachycardia syndrome.
Interpret the Rhythm
LAFB
Notes:
Left axis deviation (usually -45 to -90 degrees)
qR complexes in leads I, aVL
rS complexes in leads II, III, aVF
Prolonged R wave peak time in aVL > 45ms
What type of complex is indicated in the circle
PVC
Interpret the Rhythm
Ventricular Escape Rhythm
Notes:
Ventricular Escape Rhythm: A ventricular rhythm with a rate of 20-40 bpm.
QRS complexes are broad (≥ 120 ms) and may have a LBBB or RBBB morphology.
Also known as Idioventricular escape rhythm
Interpret the Rhythm
Accelerated Idioventricular Rhythm
Notes:
Regular rhythm
Rate typically 50-120 bpm
Three or more ventricular complexes; QRS duration > 120ms
Fusion and capture beats.
Interpret the Rhythm
Sick Sinus Syndrome
Notes:
Intrinsic Causes
Idiopathic Degenerative Fibrosis (commonest).
Ischaemia.
Cardiomyopathies.
Infiltrative Diseases e.g. sarcoidosis, haemochromatosis.
Congenital abnormalities.
Extrinsic Causes
Drugs e.g. digoxin, beta-blockers, calcium channel blockers.
Autonomic dysfunction.
Hypothyroidism.
Electrolyte abnormalitites — e.g. hyperkalaemia.
ECG in Sinus Node Dysfunction
ECG abnormalities can be variable and intermittent. Multiple ECG abnormalities can be seen in sinus node dysfunction including:
Sinus Bradycardia.
Sinus Arrhythmia — associated with sinus node dysfunction in the elderly in the absence of respiratory pattern association.
Sinoatrial Exit Block.
Sinus Arrest — pause > 3 seconds.
Atrial fibrillation with slow ventricular response.
Bradycardia – tachycardia syndrome.
Interpret the Rhythm
Ventricular Asystole
Interpret the Rhythm
Multi focal Atrial Tachycardia
Notes:
A rapid, irregular atrial rhythm arising from multiple ectopic foci within the atria.
Most commonly seen in patients with severe COPD or congestive heart failure.
It is typically a transitional rhythm between frequent premature atrial complexes (PACs) and atrial flutter / fibrillation.
Electrocardiographic Features
Heart rate > 100 bpm (usually 100-150 bpm; may be as high as 250 bpm).
Irregularly irregular rhythm with varying PP, PR and RR intervals.
At least 3 distinct P-wave morphologies in the same lead.
Isoelectric baseline between P-waves (i.e. no flutter waves).
Absence of a single dominant atrial pacemaker (i.e. not just sinus rhythm with frequent PACs).
Some P waves may be nonconducted; others may be aberrantly conducted to the ventricles.
Name the pathology
U-Waves
Interpret the Rhythm
VF
Interpret the Rhythm
Atrial Tachycardia
Notes:
Atrial rate > 100 bpm
Abnormal P wave morphology and axis (e.g. inverted in inferior leads) due to ectopic origin
Unifocal, identical P waves
Isoelectric baseline (unlike atrial flutter)
Normal QRS morphology (unless pre-existing bundle branch block, accessory pathway, or rate-related aberrant conduction)
AV block may be present — this is generally a physiological response to the rapid atrial rate, except in digoxin toxicity where there is AV nodal suppression due to vagotonic effects of digoxin, resulting in a slow ventricular rate (“PAT with block”).
Interpret the Rhythm
SVT
Interpret the Rhythm
Bidirectional VT (BVT)
Notes
Causes
This rhythm is most commonly associated with severe digoxin toxicity
It may be the presenting rhythm in patients with familial catecholaminergic polymorphic ventricular tachycardia (CPVT)
BVT has also been reported with herbal aconite poisoning
Progressively worsening ventricular arrhythmias are observed during exercise
Typical bidirectional VT develops after 1 minute of exercise with a sinus heart rate of approximately 120 beats per minute
Arrhythmias rapidly recede during recovery
Interpret the Rhythm
Artifact
This ECG shows an example of ______axis deviation.
Right Axis Deviation
The highlighted waves are P-waves. This rhythm is an example of which of the following?
AVNRT
Notes:
Atrioventricular Nodal Reentrant Tachycardia is a type of supraventricular tachycardia (ie it originates above the level of the Bundle of His) and is the commonest cause of palpitations in patients with hearts exhibiting no structurally abnormality.
Clinical Features of AVNRT
AVNRT is typically paroxysmal and may occur spontaneously in patients or upon provocation with exertion, coffee, tea or alcohol. It is more common in women than men (~75% of cases occurring in women) and may occur in young and healthy patients as well as those suffering chronic heart disease.
Patients will typically complain of the sudden onset of rapid, regular palpitations. The patient may experience a brief fall in blood pressure causing presyncope or occasionally syncope.
If the patient has underlying coronary artery disease the patient may experience chest pain similar to angina (tight band around the chest radiating to left arm or left jaw).
The patient may complain of shortness of breath, anxiety and occasionally polyuria due to elevated atrial pressure releasing atrial natriuretic peptide.
The tachycardia typically ranges between 140-280 bpm and is regular in nature. It may cease spontaneously (and abruptly) or continue indefinitely until medical treatment is sought.
The condition is generally well tolerated and is rarely life threatening in patients with pre-existing heart disease.
Pathophysiology and types of AVNRT
AVNRT is caused by a reentry circuit in or around the AV node.
The circuit is formed by the creation of two pathways forming the re-entrant circuit, namely the slow and fast pathways.
The fast pathway is usually anteriorly situated along septal portion of tricuspid annulus with the slow pathway situated posteriorly, close to the coronary sinus ostium.
Sustained reentry occurs over a circuit comprising the AV node, His Bundle, ventricle, accessory pathway and atrium.
The various forms of AVNRT can be described in terms of ECG appearance such as R-P intervals or Slow/Fast pathway dominance.
Descriptive Terminology
The ‘descriptive’ terminology regarding AVNRT classification can be confusing…and I am still confused!
Slow-Fast AVNRT (Common AVNRT)
Accounts for 80-90% of AVNRT
Associated with Slow AV nodal pathway for anterograde conduction and Fast AV nodal pathway for retrograde conduction.
The retrograde P wave is obscured in the corresponding QRS or occurs at the end of the QRS complex as pseudo r’ or S waves
ECG:
P waves are often hidden – being embedded in the QRS complexes.
Pseudo r’ wave may be seen in V1
Pseudo S waves may be seen in leads II, III or aVF.
In most cases this results in a ‘typical’ SVT appearance with absent P waves and tachycardia
Interpret the Rhythm
Torsades de Pointes
