Arrhythmias and Cardiac Arrest Flashcards
Which cells are autorythmic in the heart?
1 - smooth muscle cells
2 - myocytes
3 - pacemaker cells
4 - all of the above
3 - pacemaker cells
- make up 1% of cell in the heart
- SA and AV node are the located in the heart
The action potential that leaves the SA node does what to the heart?
1 - contraction of the ventricles
2 - contraction of the atrium
3 - contraction of the atrium and ventricles
2 - contraction of the atrium
- action potential reaches AV and slows down
The AV node is the only point that allows the action potential to move from the atria to the ventricles, and there is a delay from when the AV receives the node to when it moves into the ventricles. Why is this?
1 - diameter of AV node is small so increases resistance to electrical flow
2 - slower Ca2+ ion channels are used
3 - allows adequate time for ventricles to fill
4 - all of the above
4 - all of the above
Organise the following into the correct order for conduction through the heart?
1 - AV node
2 - purkinje fibres
3 - SA node
4 - bundle branches
3 - SA node
1 - AV node
4 - bundle branches
2 - purkinje fibres
The right bundle branch has 1 branch called a fascicle. How many does the left bundle branch have?
1 - 4
2 - 3
3 - 2
4 - 1
3 - 2
- anterior fascicle supplies anterior part of LV
- posterior fascicle supplies posterior part of LV
Do the bundle branches of purkinje fibres conduct action potentials faster?
- purkinje fibres
- this ensures heart contracts in a coordinated fashion
Are the pacemaker cells in the SA node the only method for initiating the heart to contract?
- no
- plan A = SA node
- plan B = pacemaker cells in atrium
- plan C = AV node
- plan D = pacemaker cells in bundle branches
The heart has a number of fail safes incase anything should happen to the SA node. Other parts of the heart are able to initiate a heart beat. The additional places that can generate a heart beat are:
- plan B = pacemaker cells in atrium
- plan C = AV node
- plan D = pacemaker cells in bundle branches
These areas can initiate a heart beat, but the rate would be different. Match up the new rates below with the additional locations above: 30, 40 and 60 bpm.
- pacemaker cells in atrium = 60bpm
- AV node = 40bpm
- pacemaker cells in bundle branches = 30bpm
- the above is all relative to the SA node initiating 70bpm
The pacemaker cells have automaticity to generate the heart beats. However, if any of the 4 points that can generate a heart beats go into dysfunctional automaticity they can create what?
1 - heart failure
2 - left ventricular hypertrophy
3 - arrhythmias
4 - cor pulmonael
3 - arrhythmias
- for example if SN become dysfunctional, this may cause sinus tachycardia
What does tachyarrhythmias mean?
1 - normal heart rhythm
2 - fast heart rhythm abnormality
3 - slow heart rhythm abnormality
4 - all of the above
2 - fast heart rhythm abnormality
In the ECG below we can see an abnormal heart beat than makes up aprox 1/3 of clinic visits. What is this called and where is it originating from?
1 - ventricular ectopic beats
2 - SA ectopic beats
3 - AV ectopic beats
4 - atrial ectopic beats
1 - ventricular ectopic beats
- width of QRS
- wide = ventricle
- narrow = atrial
In the ECG below we can see an abnormal heart beat than makes up aprox 1/3 of clinic visits. What is this called and where is it originating from?
1 - ventricular ectopic beats
2 - SA ectopic beats
3 - AV ectopic beats
4 - atrial ectopic beats
4 - atrial ectopic beats
- width of QRS
- wide = ventricle
- narrow = atrial
Are ectopic beats, where people describing the feeling of missing a heart beat dangerous?
- no
- can have up to 500/day
In the image attached (A and B) there appears to be a missed beat, what is this?
1 - no heart beat stimulated
2 - heart beat too fast to contract properly
3 - heart is empty and pumps very little blood
4 - can be all of the above
3 - heart is empty and pumps very little blood
- the following beat will be overly forceful, so can scare patients
Ectopic beats are generally benign, providing the patient doesn’t have any underlying heart disease. However, if the ectopic beats make up over a specific % then this can lead to ectopic induced cardiomyopathy. What % of total heart beats need to be ectopic for this to occur?
1 - >1%
2 - >5%
3 - >10%
4 - >25%
3 - >10%
- R on T wave ectopic, these are also dangerous and can induce VT
Which of the following must be performed as the basic principles of any potential arrhythmia?
1 - Document the arrhythmia on an ECG
12 lead, ambulatory monitor
2 - Exclude/identify any underlying pathology
IHD, Cardiomyopathy, valve disease, IHD, channelopathies
3 - Exclude electrolyte (low K+) disturbance, thyrotoxicosis
4 - Assess risk
eg Ectopics vs ventricular tachycardia
5 - Lifestyle
6 - Drug treatment
7 - Ablation or Device therapy (if drugs fail)
8 - all of the above
8 - all of the above
- manage the patient NOT the ECG
What is the 1st step in managing a patient with ectopic beats?
1 - exclude underlying heart disease
2 - monitor ECG (24h)
3 - evaluateV frequency of ectopic beats
4 - lifestyle changes
1 - exclude underlying heart disease
What is the 2nd step in managing a patient with ectopic beats?
1 - exclude underlying heart disease
2 - monitor ECG (24h)
3 - provide drugs
4 - lifestyle changes
2 - monitor ECG (24h)
- helps evaluate frequency of ectopic beats and rule out history of heart disease
What is the 3rd step in managing a patient with ectopic beats?
1 - exclude underlying heart disease
2 - monitor ECG (24h)
3 - provide drugs
4 - lifestyle changes
4 - lifestyle changes
- stop caffeine and alcohol
- stop elicit drugs
- stop over the count cold (sympathetic) and anti-histamines (parasympathetic)
In a patient with no known heart disease who is experiencing ectopic beats, should we prescribe medications?
- typically no
- can increase side effects
Typically we do not prescribe medications to patients presenting with arrhythmias. But if we need to, which class of drugs would we typically prescribe?
1 - Ca2+ channel blockers
2 - Na+ channel blockers
3 - B-blockers
4 - K+ channel blockers
3 - B-blockers
- low dose of propranolol taken as required
- low dose Bisoprolol taken
In addition to ectopic beats inducing abnormal arrhythmias, we have re-entry arrhythmias. This can be due to scar tissue from a previous MI. Is the heart able to send a signal around the scar tissue at the same speed?
- yes
- but generally one path will be fast conduction and one path will be slow conduction
Typically if there is a lesion in cardiac tissue, such as following an MI, there will be a fast and a slow conduction around the scar tissue. Generally the fast route dominates and the patient is fine. What happens if you have an ectopic beat occur along the fast pathway?
1 - nothing slow conduction takes over and all is ok
2 - slow pathway takes over fast pathway creating a re-entry circuit
3 - fast pathway catches up and takes over
2 - slow pathway takes over fast pathway creating a re-entry circuit
- can create a regular heart beat
- BUT can also cause a re-entry tachycardia
If you have a re-entry at the AV node (called functional micro reentry), this can cause what?
1 - ectopic beats
2 - ventricular fibrillation
3 - supraventricular tachycardia
4 - atrial flutter
3 - supraventricular tachycardia
Which of the following are ECG characteristics of supraventricular tachycardia?
1 - tachycardia (160-220 bpm)
2 - narrow QRS <120 ms (3 little squares)
3 - regular tachycardia
4 - all of the above
4 - all of the above
Supraventricular tachycardia can be caused by which of the following?
1 - AV nodal reentry tachycardia (AVNRT)
2 - Paroxysmal atrial tachycardia (AT)
3 - Atrio-ventricular reentry tachycardia (AVRT)
4 - all of the above
4 - all of the above
- AVNRT = p wave buried in QRS complex as atria and ventricle activated at the same time
- AT = p wave before QRS
- AVRT - p wave after QRS
There is also the case where some patients such as in wolf parkinsons white syndrome called functional macro re-entry. What can happen here?
1 - accentuates the link between the SA node and AV node
2 - accentuates the signal from the AV node to the ventricles
3 - accessory pathway in addition to AV node connecting the atrium and ventricles
4 - all of the above
3 - accessory pathway in addition to AV node connecting the atrium and ventricles
- if ectopic beat occurs at wrong time then this can cause a re-entry circuit between atrium and ventricles
Which of the following are characteristics of an ECG in a patient with wolf parkinsons white syndrome?
1 - short PR interval (<120ms or 0.120)
2 - delta wave - slurred upstroke of QRS complex in R wave)
3 - delta wave - slurred downstroke of QRS complex in S wave
4 - all of the above
4 - all of the above
In Wolf parkinsons white syndrome, which is caused by an accessory pathway in addition to AV node connecting the atrium and ventricles (see picture). Typically this moves to the atrium and then the ventricles and back along the accessory pathway. However, this can also move down the accessory pathway and back up the AV node. If this occurs which of the following occurs on an ECG trace?
1 - broad QRS complex
short PR interval (<120ms or 0.120)
2 - delta wave - slurred upstroke of QRS complex in R wave)
3 - delta wave - slurred downstroke of QRS complex in S wave
4 - all of the above
1 - broad QRS complex
- ventricles are activated abnormally
- resembles ventricular tachycardia
What is the 1st step of Supraventricular tachycardia management?
1 - medication
2 - lifestyle changes
3 - rule of cardiac disease
4 - ablation or device therapy
3 - rule of cardiac disease
- uncommon for wolf parkinsons white syndrome patients to have cardiac disease
- atrial tachycardia patients are likely to have underlying cardiac disease
What is the 2nd step of Supraventricular tachycardia management?
1 - medication
2 - lifestyle changes
3 - rule of cardiac disease
4 - ablation or device therapy
2 - lifestyle changes
- stop caffeine and alcohol
- stop elicit drugs
- stop over the count cold (sympathetic) and anti-histamines (parasympathetic)
If a patient presents with a supraventricular tachycardia we need to get them out of this as quickly as possible. Which 2 of the following can we use to treat this?
1 - shock therapy
2 - vagotonic manoeuvers
3 - tilt testing
4 - AV node blocker medication
2 - vagotonic manoeuvers
- carotid massage and valsalva manoeuvre
- these slow AV node and may interrupt the arrhythmia
- works in 1 in 5 patients
4 - AV node blocker medication
Prior to performing vagotonic manoeuvres, aimed at slowing the AV node, what must you do?
1 - lie the patient down
2 - auscultate carotid artery for bruit
3 - auscultate the aortic valve
4 - percuss the carotid artery
2 - auscultate carotid artery for bruit
- need to identify if they have carotid disease
- if carotid disease is present you could cause embolisation and strokes
If a patient presents with a supraventricular tachycardia we need to get them out of this as quickly as possible. We can use vagotonic manoeuvres (aimed at slowing the AV node) and AV node blocker medication. Which 2 of the following medications would be used for this?
1 - Atenolol
2 - Amiodarone
3 - Verapamil
4 - Adenosine
3 - Verapamil
- Ca2+ channel blocker
4 - Adenosine
- multiple mechanisms
To prevent a supraventricular tachycardia we need to get them out of this as quickly as possible. Which of the following drugs would NOT be used here?
1 - Flecainide
2 - Bisoprolol
3 - Amiodarone
4 - Verapamil
3 - Amiodarone
Atrial tachycardia: atrial stabiliser = Bisoprolol
AV nodal reentry: AV node blocker = Bisoprolol, Verapamil)
WPW – accessory pathway blocker = Flecainide)
Electrophysiological studyand Ablation is a method where multiple pacing wires are passed into the heart (RA, RV, bundle of HIS and coronary sinus). This allows a programmed electrical stimulation to provoke arrhythmias, allowing mapping of the arrhythmia. What is the purpose of this approach?
1 - identify the arrhythmia and then burn local tissue, creating scar
2 - identify the arrhythmia and then give drugs
3 - identify the arrhythmia and then give lifestyle advice
4 - all of the above
3 -
1 - identify the arrhythmia and then burn local tissue, creating scar
- aim is to interrupt the re-entry circuit
- 90% effective and treatment of choice in younger patients
The most common tachycardia is sinus tachycardia. Which of the following can cause sinus tachycardia?
1 - reactive response
2 - thyrotoxicosis
3 - severe anaemia
4 - pulmonary embolism
5 - intrinsic sinus node dysfunction (rare)
6 - all of the above
6 - all of the above
- reactive response = Fever, Pain, Emotional stress / anxiety, Dehydration, Stimulant drugs and Low BP
- essentially a stress response
There are some serious arrhythmias, which is the most common serious arrhythmia?
1 - atrial flutter
2 - supraventricular tachycardia
3 - ventricular tachycardia
4 - atrial fibrillation
4 - atrial fibrillation
- 2.5% prevalence in the UK
- has m
Is atrial fibrillation caused by multiple functional micro or macro re-entry?
- macro re-entry
- multiple of these in the atria
- causes rapid and irregular atrial contractions that send this signal to the ventricles
Which of the following underlying structural heart diseases is atrial fibrillation common in?
1 - IHD
2 - cardiomyopathies
3 - valvular disease (mitral with LA dilation)
4 - all of the above
4 - all of the above
Which of the following conditions is atrial fibrillation common in?
1 - Hyperthryoidism
2 - Hypertension
3 - Obesity
4 - Pbstructive sleep apnoea
5 - all of the above
5 - all of the above
- hypertension is most common cause
What is the diagnosis in the ECG?
1 - RBBB
2 - NSTEMI
3 - AF
4 - atrial flutter
3 - AF
Which of the following is NOT a key characteristic on an ECG in a patient with atrial fibrillation?
1 - irregular RR intervals
2 - regular sinus rhythm
3 - no clear P waves
4 - no 2 QRS complexes are the same
2 - regular sinus rhythm
Which of the following are typical symptoms that patients present with in AF?
1 - palpitations
2 - breathlessness
3 - dizziness
4 - fatigue
5 - all of the above
5 - all of the above
- symptoms and rhythm can be intermittent or persistent