Quiz 2 -- Rhythm Flashcards
Questions to ask about rhythm?
- Is the rhythm fast or slow?
- Is the rhythm regular or irregular
- Are there P waves?
- Is the QRS wide or narrow?
- Is the P “married” to the QRS?
- Do all P waves look the same?
- Are the PR intervals constant?
- Is there a P wave for every QRS complex?
What do you look for to see if the rhythm is regular or irregular?
R-R Intervals
When there is a repeating pattern of irregular beats, what is this called?
Regularly irregular
When there is no pattern of irregular beats, what is this called?
Irregularly irregular
What are the 3 exclusive irregularly irregular rhythms?
- A. Fib
- Wandering Atrial Pacemaker
- Multifocal Atrial Tachycardia
What does an upright P wave in lead II indicate?
Sinus Rhythm
If P waves are present, where are they coming from?
Supraventricular Origin
If the P wave is present and upright, then what does this mean?
Sinus Node or High Atrial
If the P wave is present and inverted, then what does this mean?
Low Atrial or AV Nodal (aka Junctional)
If there is no P wave present and a NARROW QRS, what does this indicate?
AV Nodal (Junctional)
If there is no P wave present and a WIDE QRS, what does this indicate?
Ventricular
What does the P wave represent?
Atrial Depolarization
Why is the normal P wave upright in lead II?
It’s going towards the positive direction (down the electrical axis).
Impulse originates in _________ then travels _______ to depolarize atria as well as ______ to depolarize ventricles.
AV Node; Retrograde; Antegrade
If retrograde conduction of the impulse is FAST (depolarizing the atria), what would we see?
Negative P wave BEFORE QRS (short PR interval)
If retrograde conduction of the impulse is SLOW (depolarizing the atria), what would we see?
Negative P AFTER QRS
If retrograde conduction (depolarizing the atria) of the impulse is the same as the antegrade conduction (depolarizing the ventricles), what would we see?
NO P wave (it is hidden in the QRS)
If there is a narrow QRS and NO P wave, what should we think?
Junctional (AV Nodal)
What are the most common types of P wave anomalies in Junctional Rhythms?
- No P wave at all
2. Negative P wave after QRS
Why is it important to know if there is a QRS for each P wave?
To recognize heart block!
Tell me everything you know about the Normal Sinus Rhythm!
- Rate: 60-100 bpm
- Regular
- P wave present
- QRS narrow
- P and QRS are married (1:1 ratio)
Tell me everything you know about the Normal Sinus Arrhythmia!
- Rate: 60-100 bpm
- Irregular and varies with respiration
**Otherwise the same as NSR, and this is benign!
Tell me everything you know about the Normal Sinus Bradycardia!
- Rate: < 60 bom
Otherwise similar to NSR
Caused by? Medication, Vagal Stimulation, SSS, Inferior Ichemia/Infarct.
Commonly seen in athletes
Tell me everything you know about the Normal Sinus Tachycardia!
- Rate > 100 bpm
- Otherwise Similar to NSR
- Found in high cardiac output states (exercise, fever, hyperthyroidism, hypovolemia)
This is a rhythm that deals with impulse formation and originates from tissue other than the SA Node.
Ectopic Rhythm
Faster automaticity focus will suppress slower one.
Overdrive Suppression
What are two causes of ectopic rhythms?
- Another pacemaker cell fires at a rate faster than SA node = premature beat
- Slowing of SA node rate allowing slower focus to take control = escape beat
This is the term for an ectopic beat that occurs early before the scheduled sinus beat.
Premature Beats
Impulse originating in the atria that occurs early (before the scheduled sinus beat).
Atrial Premature Contraction (APC)
Impulse originating in or near the AV Node/Junction that occurs early (before the scheduled sinus beat).
Junctional Premature Contraction (JPC)
Impulse originating in the ventricular that occurs early (before the scheduled sinus beat).
Ventricular Premature Contractions
Tell me about Atrial Premature Contraction
- Another atrial pacemaker cell fires faster than SA node
- Noncompensatory pause- PAC resets SA node
- P wave may be different morphology
- Narrow QRS
Tell me about Ectopic Atrial Tachycardia
- Run of atrial premature complexes
- Rates: 100-180 bpm
- Regular
- P wave has different morphology
- Narrow QRS
When you have a rate less than 100 pm, it is IRREGULARLY irregular with no consistent pacemaker. P waves present with 3+ morphologies and a narrow QRS.
Wandering Atrial Pacemaker
When you have a rate greater than 100 pm, it is IRREGULARLY irregular with no consistent pacemaker. P waves present with 3+ morphologies and a narrow QRS. This is commonly found in patients with severe lung dz.
Multifocal Atrial Tachycardia
What do you want to do if you see Multifocal Atrial Tachycardia?
Treat the underlying pulmonary process.
This is a beat that originates in or near AV node. There is no P wave visible (it is hidden within the QRS complex). Sometimes it is inverted after QRS. QRS will be narrow.
Junctional Premature Contraction
Tell me about Ventricular Premature Complex
- Beat that originates from ventricular cell
- No P wave
- QRS wide (different conduction pathway)
- Because ventricles in refractory state when normal pacemaker fires, followed by compensatory pause
This is a complex where there is one group of premature beats.
Premature Ventricular Complex
This is a complex where there is two groups of premature beats.
Couplet Premature Ventricular Compelxes
This is a complex where there are three or more groups of premature beats lasting less than 30 seconds
Nonsustained Ventricular Techycardia (NSVT)
This is a pattern of Premature Ventricular Complexes that happen every other beat.
Ventricular Bigeminy
This is a pattern of Premature Ventricular Complexes that happen every third beat.
Ventricular Trigeminy
What does a PVC mean?
It can be benign or malignant depending on the patient.
A new onset of PVCs or frequent PVCs in the setting of ischemic heart disease should be evaluated further.
What are types of atrial ectopic rhythms?
- Atrial Premature Complex (APC or PAC)
- Ectopic Atrial Tachycardia
- Wandering Atrial Pacemaker
- Multifocal Atrial Tachycardia
What are escape beats and what do they represent?
Escape beats are ectopic beats that occurs late! They represent “rescue” beats after normal pacemaker delays or is temporarily failing.
Are escape beats dangerous?
Not necessarily, they are more necessary because without them you wouldn’t have a beat at all if there was a delay or temp. failure.
Examples of Escape Beats
- Atrial Escape: 60-75 bpm
- AV Node/Junctional: 40-60 bpm
- Ventricular: 20-40 bpm
This is an escape beat that occurs when the SA node fails to fire and the AV nodal cell is the next available pacemaker
Junctional Escape Beat
How would you see a junctional escape beat on an EKG?
- P wave would be hidden in the QRS complex
- Narrow QRS complex
Inverted P can be after or before QRS, but this is rare
This is an escape beat where the AV/junctional pacemaker fires faster that normal causing a rate of 60-100 bom. Similar to the junctional rhythm
Accelerated Junctional Rhythm
This is defined as a rate of 100+ bpm and similar to a junctional rhythm.
Junctional Tachycardia
What is the most common cause of junctional tachycardia and accelerated junctional rhythm?
Digoxin Toxicity
This is an escape beat that occurs when the SA node fails to fire and the next available pacemaker cell is ventricular.
Ventricular Escape Beat
How would a Ventricular Escape Beat present on an EKG?
No P wave and a Wide QRS
This is an escape beat that occurs when the ventircular focus acts as the primary pacemaker for the heart (everything above it has not failed). It causes a bpm of 20-40.
Idioventricular Escape Rhythm
How would an idioventricular escape rhythm present on an EKG?
No P wave and a Wide QRS in a regular pattern.
This is an idioventricular rhythm that is at a rate of 40-100 bpm
Accelerated Idioventricular rhythm
Deals with impulse transmission and is usually initiated by a critically times premature beat which precipitates reentry. This commonly produces tachycardia.
Reentrant Rhythm
This type of beat has a rate of 150-220 bpm. The pattern is regular with no P wave and a narrow QRS.
PSVT (Paroxysmal Supraventricular Tachycardia)
What is the hallmark of a PSVT?
Begins and ends abruptly.
What commonly causes PSVT?
Generally due to AV nodal reentry mechanism: The impulse circulates in the AV node until terminated. No P wave will be seen because it is a retrograde atrial depolarization.
T/F: You will commonly see PSVTs in patients that have a structural heart dz or defect.
False, see in pts without this.
Difference between SVT and PSVT
SVT - broad term, and sometimes underlying rhythm is atrial flutter or atrial fibrillation.
PSVT - abrupt beginning and end, and AV node re-entry tachy.
Where does Atrial Flutter originate?
Right Atrium
This is a type of beat that consists of regular, fast atrial activity (250-350 bpm). And the ventricular rate depends on conduction through the AV node (often 150 bpm).
Atrial Flutter
What will you see on an EKG for Atrial Flutter?
P wave present at at times buried in a saw tooth pattern.
Narrow QRS
Rule of thumb: When the rate is close to 150 bpm, look for buried P waves of atrial flutter with 2:1 conduction.
2:1 means, if the atrial is roughly 300 bpm, then the ventricular is 150 bpm.
***Sometimes A. Flutter is 3:1 or 4:1, but mostly 2:1
Where does atrial fibrillation commonly originate?
Around the Pulmonary Veins
What can A.Fib cause?
- Chaotic Atrial Activity – No atrial contraction
- Irregular ventricular contraction
How would A. Fib appear on an EKG?
- Rate variable – usually fast
- Irregularly irregular
- No P wave
- Narrow QRS
How is A. Fib classified?
By Ventricular Rhythm:
- Afib with rapid ventricular response/”RVR”
- Afib with controlled ventricular response
- Afib with slow ventricular response- generally due to medication or sick sinus syndrome.
This type of heart beat is a re-entrant rhythm due to an accessory pathway between atrium and ventricle called the “Bundle of Kent.” It is commonly associated with tachycardias. Sometimes referred to as the “pre-exciteation” syndrome.
Wolff-Parkinson-White Syndrome
How would Wolff-Parkinson-White Syndrome appear on an EKG?
- Normal P wave
- PR interval is SHORT <0.12 seconds
- Impulse bypasses the AV Node through accessory pathway
- Wide QRS
- Delta Wave
- ST-T wave changes
This is a fatal rhythm and is a medical emergency!
Ventricular Tachycardia
How would V. Tach appear on an EKG?
- Rate > 120 bpm (usually 150-300 bpm)
- Regular
- Wide QRS
- No marriage of P and QRS = AV dissociation (P is commonly hidden in the QRS)
This is a complex in V. Tach that is caused by a combination of both Sa and Ventricular pacemaker
Fusion Beat
This is a beat in V.Tach that is a normally conducted sinus beat.
Capture Beat
What can cause Wide Complex Tachycardias?
- Ventricular Tachycardias!
- SVT with aberrancy (aka Pre-existing BBB, rate-related aberrancy, preexcitation syndrome/accessory pathway (WPW))
- Pacemakers/Defibrillators
- Artifact mimicking Ventricular tachycardia
EKG findings of REGULARITY in V. Tach vs. SVT with Aberrancy
V. Tach - May be slightly irregular
SVT with Aberrancy - Always regular
EKG findings of AV DISSOCIATION in V. Tach vs. SVT with Aberrancy
V. Tach - Often seen
SVT with Aberrancy - Never seen
EKG findings of FUSION BEATS in V. Tach vs. SVT with Aberrancy
V. Tach - Often seen
SVT with Aberrancy - Never seen
EKG findings of INITIAL QRS DEFLECTION in V. Tach vs. SVT with Aberrancy
V. Tach - Often opposite pts usual QRS deflection
SVT with Aberrancy - Same as PTs usual QRS deflection
Rule of thumb with Wide Complex Tachy:
Ventricular Tachycardia until proven otherwise
This is a polymorphic Ventricular Tachycardia with a rate of 200-250 bpm. The QRS morphology of this twists around the baseline like a party streamer
Torsades de Pointes
What is an EKG finding with Torsades de Pointes?
Assc with prolonged QT interval. Usually due to Congenital, drugs, or electrolyte disturbances.
How do you treat Torsades de Pointes? Is it dangerous?
It is very serious and often degenerated to Ventricular Fibrillation.
Tx: IV Magnesium
This type of rhythm is define as chaotic ventricular activity with no discernible rate.
Ventricular Fibrillation
What will you see on Ventricular Fibrillation on an EKG?
No P or QRS = Cardiac Arrest
A flatline with death or disconnected lead is called?
Asystole
T/F: You can have a rhythm without a pulse
True. It’s called a Pulseless Electrical Activity
