Arrhythmias and Heart Failure Flashcards

1
Q

What are the two basic causes of arrythmias?

A

Two basic causes of arrythmias:
* Malfunction of the conduction system (more common):
* Abnormal impulse generation (abnormal automaticity):

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which is the more common cause of arrythmias,
a.Malfunction of the conduction system
OR
b.Abnormal impulse generation

A

Malfunction of the conduction system is the most common cause of arrhythmias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two types of the malfunction of the conduction system?

A

Two types of malfunction of the conduction system:
1. Re-entry: re-excitation around a conducting loop, which produces tachycardia
2. Heart block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an arrythmia?

A

An arrhythmia is an abnormal heart rhythm.
Abnormal eletrical activity of the heart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is tachycardia?

A

Tachycardia is a heart rate over 100 beats per minute at rest.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the ST segment clinically important for?

A

The ST segment is clinically important for ischaemia and myocardial infarction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What can the T wave indicate?

A

The T wave could indicate high potassium levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a normal heart beat?

A

A normal heart beat is 60-100 beats per minute.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is bradycardia?

A

Bradycardia is a heart rate less than 60 beats per minute at rest.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 stages of a heart beat?

A

The 3 stages of a heart beat are:
1. Atrial depolarisation
2. Ventricular depolarisation
3. Atrial and ventricular repolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the P wave represent?

A

P wave represents atrial depolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the QRS complex represent?

A

The QRS complex represnts ventricular depolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the T wave represent?

A

The T wave represents ventricular repolarisation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The heart is ?% electrical cells and ?% muscle cells?

A

The heart is 1% electrical cells and 99% muscle cells?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Normal heart rate/rhythm starts and ends where?

A

Normal heart rate/rhythm starts and ends in the SA node.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does the PR interval allow for?

A

The PR interval allows for the ventricles to fill up.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How long shouldn’t the P-R interval be?

A

The P-R interval shouldn’t begreater than 0.2 seconds it could indicate issues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The term used for the release (discharge) of an electrical stimulus is “?”, and the term for recharging is “?

A

The term used for the release (discharge) of an electrical stimulus is “depolarisation”, and the term for recharging is “repolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The SA node ? whilst the atria are refilling, and the AV node recharges when the ventricles are ?

A

The SA node recharges whilst the atria are refilling, and the AV node recharges when the ventricles are refilling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Any part of the heart can do what?

A

Any part of the heart can excite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What can malfunction of the conduction system be caused by?

A

Malfunction of the conduction system can be caused by:
* unidirectional conduction block
* establishment of new loop of excitation
* conduction that outlasts the refractory period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the refractory period?

A

The refractory period is a period of time during which a cell is incapable of repeating an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe normal conduction

A

Normal conduction:
SA node to atria to AV node to apex to bundle of HIS to purkinje fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are autorhythmic cells?

A

Authorhythmic cells:
* Specialised muscle cells
* Spontaneously generate action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the two types of autorhythmic cells?
Two types of auto rhythmic cells: * Pacemaker cells * Conducting fibres
26
What does the pulmonary artery do?
The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs
27
What does ventricular depolarisation allow for?
Ventricular depolarisation allows for contraction.
28
What should the S-T segment b? What does it represent?
The S-T segment should be iso-electric It represents the ventricles before repolarisation
29
The PR interval is the time from onset of ? activation to onset of ? activation
The PR interval is the time from onset of atrial activation to onset of ventricular activation
30
The QT interval is the duration of ? activation and recovery
The QT interval is the duration of **ventricular** activation and recovery
31
What should the QT interval not be?
The QT interval shouldn't be too wide or too narrow.
32
What can more than one P wave for each QRS-T complex indicate?
More than one P wave for each QRS-T complex could indicate heart block
33
What is heart block? What may it result in?
Heart block: * Partial damage to AV node may lead to intermittent heart block * Resulting in more than one P wave for each QRS-T complex
34
What are extra-systoles?
Extra-systole= extra contraction
35
What is abnormal impulse generation?
Abnormal impulse generation (abnormal automaticity): * Beat originates from a part it shouldn't (should be from SA node) * Ectopic beats may originate in atria or ventricle in the absence of any nodal damage and initiate extra-systoles
36
What might show on an ECG with atrial fibrillation?
Atrial fibrillation ECG: * QRS complex may still be evident but superimposed on an irregular baseline * No clear P wave
36
What can the heart do if it has issues?
If the heart has issues, it can generate a beat from any area.
37
Name the 4 types of arrhythmia
4 types of arrhythmia: * Tachycardia: increased rate * Bradycardia: decreased rate * Fibrillation: disorganised contractile activity * Flutter: very rapid but regular contractions
38
What can ventriular fibrillation lead to?
Ventricular fibrillation can lead to cardiac arrest or death.
39
Ectopic beat?
Ectopic beat: a part of the heart (not the SA node) generating a rhythm
40
What is fibrillation?
Fibrillation: * The heart generates multiple etopic beats * multiple ectopic foci develop and discharge asynchronously * there is no coordination
41
Is atrial fibrillation or ventricular fibrillation more common?
Atrial fibrillation is more common than ventricular fibrillation.
42
Which drugs are available for arrhythmias?
Arrhythmia drug treatment: * Class I: Sodium channel blockers (e.g. lignocaine) * Class II: Beta blockers (e.g. propranolol) * Class IIi: Drugs that delay repolarization/slow heart rate (Amiodarone) * Class IV: Calcium channel blockers (e.g. verapamil and nifedipine) * Class V: "Atypical" (e.g. adenosine, digoxin and anticoagulants).
43
Which symptoms are associated with arrythmia?
Symptoms associated with arrhythmia: * Palpitations * Dizziness * Chest pain * Dyspnea (breathing issues) * Fainting * Sudden cardiac death
44
If heart rate is low what is the PR interval likely to be?
If heart rate is low, the PR interval is likely to be longer.
45
If heart rate is high what is the RR interval likely to be?
If heart rate is high, the RR interval is likely to be closer.
46
Which sites can be involved in arrhythmia?
Sites involved in arrhythmia: * Ventricular * AV node * Atrial * Sinus * Supraventricular (atrial myocardium or AV node)
47
What does a 3rd degree block have on an ECG?
On a ECG a 3rd degree block has many P waves
48
What does an elevated ST segment indicate?
An elevated ST segment may indicate acute myocardium damage from myocardial ischaemia
49
What does a depressed ST segment indicate?
A depresed ST segment may indicate myocardium damage and ischaemia.
50
What does an ECG do?
ECG: Show heart behaviour Accurate & detailed detection of cardiac abnormalities which may be related to myocardium damage or issues with conduction
51
What might a ventricular fibrillation ECG show?
Ventricular fibrillation ECG: * Might not have any QRS-T waves (they won't be completely flat)
52
What does a delay at the AV node lasting for more than 0.2s result in?
A delay at the AV node lasting for more than 0.2s leads to a heart block.
53
What is heart failure?
Heart failure: - the heart's inability to meet the metabolic requirements of the body - heart could be pumping but not meeting metabolic demand/rate - Disease of heart: associated with poor contracility of heart muscles, occurs when heart is unable to mainatin sufficient cardiac output to meet the demands of the body
54
Chronic heart failure
Chronic heart failure * Gradual inability of the heart to maintain blood supply
55
Acute left ventricular failure
Acute left ventricular failure Usually results from sudden inability of the heart to maintain blood supply
56
Left-sided heart failure
Left-sided heart failure * an inability of the left ventricle to pump out enough blood and as a result, * * blood backs up into the lungs, * causes pulmonary oedema
57
Right-sided heart failure
Right-sided heart failure * Right ventricle fails to pump out enough blood, * fluid backs up into the veins and capillaries * causes systemic oedema particularly in the legs
58
Heart failure causes
Causes of heart failure Coronary artery disease Diseases of the heart muscle Abnormal heart rhythms Leaky heart valves High Blood Pressure Infections: viral or bacterial Some chemotherapy drugs Toxins such as alcohol Birth defects- congenital heart disease
59
Heart failure treatments
Heart failure treatments * Cardiac glycosides: e.g digoxin: inhibit na/K exchange, increase Na> decreased na/Ca exchange: increased Ca> increased contraction * Angiotensin II blockers * Beta-receptor agonists (Acute HD) eg Dobutamine:Activate Beta 1-receptor in the heart and thus increase force of contraction * Vasodilators: reduce afterload and peripheral vascular resistance * Diuretics: fluid retention increases pre load. * Diet * Exercise * Stop smoking * Reduce alcohol intake * Heart transplant
60
Why are selective beta1 antagonists used in heart failure?
Selective beta1 antagonists are used in heart failure: * To not increase the afterload which will happen if peripheral alpha receptors are stimulated> cause blood vessel constriction * Increased afterload will increase heart workload and impair cardiac output more
61
Angiotensin II mechanism of action
Angiotensin II mechanism of action * Constrict Efferent arterioles * Acts on CNS to increase ADH production Sympathetic tone * Stimulate aldosterone secretion * Na+ retention * Increase fluid retention * Vasoconstrict venous reservoir * Increase blood volume
62
What does blocking angiotensin II do?
Blocking angiotensin II: reduces workload on the heart by preventing: aldosterone secretion, fluid retention and blood volume increase