Pathophysiologies Of The Cardiovascular System Flashcards
1
Q
What are arrhythmias?
A
- the rhythm of the heart becomes irregular
2
Q
Why do arrhythmias happen?
A
- tachycardia
- bradycardia
- atrial fibrillation
- supraventricular tachycardia
- heart block
- ventricular fibrillation
3
Q
Tachycardia?
A
Heart beats too fast
4
Q
Bradycardia?
A
Heart beats too slow
- the frequency of atrium & ventricle contractions are altered
5
Q
Atrial fibrillation?
A
- most common
- heart beats irregularly & faster than normal
6
Q
Supraventricular tachycardia?
A
Episodes of abnormally fast heart rate at rest
7
Q
Heart block?
A
- heart beats more slowly than normal, can cause people to collapse
8
Q
Ventricular fibrillation?
A
- rare, rapid & disorganised heart rhythm
- can lead to loss of consciousness & sudden death, if not treated right away
9
Q
How common are arrhythmias?
A
- 5% of population
- related to age & underlying heart disease
10
Q
Symptoms of arrhythmias?
A
- palpitation in chest
- skipped beat
- racing heart
- shortness of breath
- fainting
- heart failure symptoms
- chest pain
- cardiac arrest
11
Q
Causes of arrhythmias:
A
- Coronary artery disease
- Changes in cardiac structure that accompany heart failure
- Drugs
12
Q
- Coronary artery disease =
A
- results in myocardial ischemia
- cardiac cells lack oxygen, they become depolarized
- leads to altered impulse formation
- caused by changes in the SA node, or abnormal generation of action potentials at ectopic foci
- altered impulse conduction = complete / partial block of electrical conduction within the heart
13
Q
- Changes in cardiac structure that accompany heart failure
A
- ventricular dilation = stretching
- ventricular hypertrophy = enlargement
- dilated cardiomyopathy = dilated ventricle
14
Q
- Drugs
A
- drugs that effect the speed of the heartbeat and the strength of the contraction
15
Q
Beta-blockers =
A
- block sympathetic stimulation
- block beta adrenergic receptors
16
Q
Electrolyte disturbances:
A
- potassium and calcium ions
- can precipitate arrhythmias
17
Q
Consequences of arrhythmias:
A
- benign
- or more serious
18
Q
Benign consequences:
A
- occasional premature ventricular complexes
- not treated
19
Q
More serious consequences:
A
- can lead to heart failure and death
- treated aggressively with anti-arrhythmic drugs
20
Q
Arrhythmia treatment:
A
- medication
- cardioversion
- catheter ablation
- pacemaker
- ICD
21
Q
Medication?
A
- to stop or prevent any arrhythmia or control the rate of an arrhythmia
22
Q
Cardioversion?
A
- uses electricity to shock the heart back into a normal rhythm, while the patient is anaesthetised / sedated
23
Q
Catheter ablation?
A
- a keyhole treatment under local / general anaesthetic, to destroy diseased tissue that causes arrhythmia
24
Q
Pacemaker?
A
- small device implanted in the chest under local anaesthetic which produces electrical signals to help the heartbeat at a normal rate
25
ICD?
- device that monitors your heart rhythm & shocks your heart back into a normal rhythm when needed
26
Cardiac valve disease:
- valves regulate blood flow through the heart
- they stop the backflow of blood through the heart
- heart valves can become diseased or damaged
- they may not fully open or close
27
Causes of cardiac valve disease in older individuals:
- chronic diseases
- bacterial / viral infection
- inflammation of valves
- triggers changes in the thickening of the valve structure
28
Causes of cardiac valve disease in younger individuals:
- congenital defects in heart development
29
What else causes cardiac valve disease?
- coronary artery disease
- cardiac hypertrophy
- cardiac dilation
30
What are the two types of cardiac valve defect?
1. Stenosis
2. Insufficiency
31
What is stenosis?
- narrowing of the valve opening
- caused by thickening & increased rigidity
- calcification occurs
32
What is insufficiency?
- valve doesn’t completely close
- valve can be floppy
- regurgitation of blood happens
33
Symptoms of cardiac valve disease:
- shortness of breath
- fatigue
- reduced exercise capacity
- heart failure
- pulmonary hypertension
- pulmonary oedema
- chest pain
- arrhythmia
- blood clots
34
Three ways of treating cardiac valve disease:
1. Lifestyle changes
2. Medication
3. Valve replacement
35
Lifestyle changes:
- if symptoms are absent / minor
- stop smoking
- reduce caffeine
- lessen the strain on your heart
36
2. Medication
- if symptoms are present
- you may get beta-blockers to reduce the strain on your heart
37
3. Valve replacement
- if symptoms are more severe
- surgery may be needed to replace the valve
38
What is coronary artery disease?
- coronary arteries supply blood to the heart
- ensures adequate oxygenation of heart muscle
- constriction & dilation = local regulatory mechanisms
39
What causes coronary artery disease?
- changes in the structure and function of blood vessels
1. Atherosclerosis
2. Endothelial dysfunction
40
1. Atherosclerosis
- causes a narrowing of the lumen
- restricts blood flow
- can occlude the vessel
41
2. Endothelial dysfunction
- leads to coronary vasospasm
- formation of blood clots
- can occlude the vessel
42
What causes atherosclerosis?
- endothelial cell injury
- lipid accumulation in the vessel wall
43
What does atherosclerosis result in?
- endothelial dysfunction
- endothelium interprets lipid deposition as a danger
- immune cells recruited
- macrophages & T-cells
- inflammatory response
- atherosclerotic plaque forms
44
Atherosclerotic plaque can cause problems:
- occlusion of artery disrupts the blood flow
- plaque disruption can cause a clot
45
How is a fibrous cap formed after atherosclerosis:
- smooth muscle migration
- foam-cell formation
- T-cell activation
- adherence & aggregation of platelets
- adherence and entry of leukocytes
- macrophage accumulation
- formation of necrotic core
- fibrous-cap formation
46
Coronary artery disease summary:
- restricts blood flow to heart tissue
- chest pain
- lead to myocardial infarction
- heart failure & arrhytmias
47
How is coronary artery disease treated?
- balloon angioplasty
- stents
48
Coronary artery bypass:
- creates a new path for blood to go around a blocked or partially blocked artery in the heart tissue
49
Myocardial infarction:
- heart attack
- results from coronary artery disease or blockage of coronary artery
- blood supply to heart muscle is cut off & cannot function properly
- treated by removing blood clots to relieve symptoms
- rapid treatment alongside anti-clotting agents
50
Heart failure:
- inability of the heart to supply adequate blood flow and oxygen to peripheral tissues and organs
- can be intrinsic or external
51
Intrinsic meaning?
Factors originating from the heart
52
External meaning?
Factors that place excessive demands upon the heart
53
Chronic?
Results from the heart undergoing a long term adaptive response
54
Acute?
Rapid onset
55
Intrinsic causes of heart failure:
- coronary artery disease
- myocardial infarction
- cardiac valve disease
- chronic arrhytmias
- cardiomyopathy
- myocarditis
56
What is cardiomyopathy?
- defect on heart muscle
- can be of known origin = infection
- or idiopathic = spontaneous onset
57
What is myocarditis?
- inflammation of heart muscle caused by infection
58
External causes of heart failure:
- hypertension
- increased stroke volume = arterial-venous shunts
- increased body demands = pregnancy
59
Treatment of heart failure:
- if the cause is known = treated accordingly
- chronic:
- lifestyle changes = healthy diet, exercise, stop smoking
- medication = take strain of the heart
- heart transplant
60
Tissue oedema:
- tissue swelling due to fluid accumulation
- can be highly localized, or effect entire limbs / organs
- most capillary systems allow fluid to move from vasculature to tissues
- lymphatic systems removes the excess fluid
61
Causes of tissue oedema:
1. Increased capillary hydrostatic pressure
2. Hypoproteinemia
3. Increased capillary permeability
4. Lymphatic obstruction
62
1. Increased capillary hydrostatic pressure
- venous pressure is elevated by gravity
- heart failure
- venous obstruction
63
2. Hypoproteinemia
- too little protein in blood
- causes osmotic loss of liquid from blood
64
3. Increased capillary permeability
- pro-inflammatory mediators
- capillary damage due to tissue trauma or burns
65
Treatment of tissue oedema:
- need to alter one or more physical factors that regulate movement
- use diuretics to reduce blood volume & venous pressure
- ankle oedema:
- elevate feet to stop gravity effecting capillary pressure
- tight fitting stocking to increase tissue hydrostatic pressure
- diuretic drug = enhances fluid removal by kidneys
66
Peripheral arterial occlusive disease:
- comes from athersclerosis which narrows the lumen of the artery
- thrombus formation
- similar to coronary artery disease
- occludes 60% of lumen
- can lead to = limb ischemia
- weakness & ischemic pain during exercise
- lack of blood flow to limb
67
Atherosclerotic aneurysm of the aorta;
- atherosclerotic lesions can lead to aneurysms
- large bulge in the aorta
- prone to rupture when they reach 6-7cm in size
- may be felt on a physical examination as a mass in the abdomen
- treated by a surgical resection
68
Hypertension:
- leading cause of morbidity & mortality
- effects kidney, brain & eye
- many are asymptomatic until damaging effects occur = stroke, heart attack etc
69
What is classified as hypertension diastolically?
Diastolic pressure of 90mmHg or greater
70
What is classified as hypertension systolically?
Systolic pressure of 140mmHg or greater
71
Primary hypertension cause =
Unknown
72
Secondary hypertension cause =
- renal disease
- endocrine disorders
73
What are both types caused by?
- increase in systemic vascular resistance
- increase in cardiac output
- elevation in blood volume
74
Primary hypertension summary:
- in some cases, may be due to kidney not being able to handle sodium
- increased sodium retention = increase in blood volume
- in chronic cases, blood volume & cardiac output = normal
- sustained by elevation in systemic vascular resistance
- endothelium = produces less noradrenaline, vascular smooth muscle is less sensitive to it
- this is evidence type 2 diabetes causes endothelial dysfunction
75
Secondary hypertension summary:
- renal artery stenosis - renovascular disease:
- reduce the lumen diameter, increases the pressure drop along the diseased artery
- reducing the pressure of the afferent arteriole in the kidney
- reduced arteriolar pressure & reduced renal perfusion = stimulates renin to be released by the kidney
- chronic renal disease:
- damage nephrons in kidney
- inhibits the excretion of normal amounts of sodium
- water retention occurs
- can also increase the release of renin
76
Primary hyperaldosteronism:
- adrenal adenoma = increased aldosterone secretion
- causes renal retention of sodium & water
77
Stress:
- activates the sympathetic nervous system
- increased cardiac output & systemic vascular resistance
- adrenal medulla secretes more = noradrenaline and adrenaline
78
Sleep apnea:
- stop breathing for short periods of time during their sleep
- sympathetic activation & hormonal changes = repeated periods of apnea induced hypoxia & hypercapnia
- stress = loss of sleep
79
Pheochromocytoma:
- catecholamine secreting tumours found in the adrenal medulla
- high levels of adrenaline & noradrenaline
- causes sympathetic vasoconstriction & stimulation of the heart
80
Preeclampsia:
- develops during third trimester of pregnancy
- hypertension = due to increased blood volume & tachycardia
81
Thyroid dysfunction:
- excessive thyroid hormones
- systemic vasoconstriction
- increased blood volume
- increased cardiac activity
82
Aortic coarctation:
- congenital defect that obstructs aortic outflow
- elevated pressure
- baroreceptors reflex = blunted, due to structural changes of the vessels where they are located
83
Risk factors of hypertension:
- over 65
- overweight
- African / Caribbean descent
- relative with high blood pressure
- too much salt
- not enough fruit or veg
- not exercising enough
- drink too much alcohol, coffee or energy drinks
- smoker
- disturbed sleep
84
Treatment of primary hypertension:
- lifestyle changes
- treatments from blood pressure notes
85
Treatment of secondary hypertension:
- treat the cause
86
Stroke:
- brain needs oxygen & nutrients
- if blood supply is restricted / stops = brain cells die
- can lead to brain injury, disability & death
87
What are the two main types of stroke?
1. Ischaemic
2. Haemorrhagic
88
Ischaemic stroke =
Blood supply stopped due to a blood clot
89
Haemorrhagic stroke?
- weakened blood vessel supplying the brain bursts
90
Mini stroke = transient Ischaemic attack
- blood supply to brain temporarily interrupted
- can last up to 24 hours
- treated urgently, risk of a full stroke
91
Symptoms of a stroke:
- face
- arms
- speech
92
1. Face
- drops on 1 side
- may not be able to smile
- mouth / eyes drop
93
2. Arms
- not be able to lift both arms or keep them there
- due to numbness
94
3. Speech
- slurred, not able to talk even though awake
- problems understanding others
95
Treatment of a stroke:
- medication = prevent & dissolve blood clots, reduce blood pressure, reduce cholesterol levels, procedures to remove blood clots or treat brain swelling, to reduce further risk of bleeding
96
Evolution on the cardiovascular system:
- emissions, wildfires, dust / sand
- rise in mortality
- heart attack, heart failure, stroke, arrhytmias
- hypertension upon exposure
97
Extremes of heat:
- hot / cold spells
- general temperature rise
- hypertension & clotting factors upon exposure
98
Risk factors:
- age
- socioeconomic background
- ethnicity
- jobs working outside
99
Pathophysiology to do with the heart;
- arrhythmia
- cardiac valve disease
- coronary artery disease
- heart failure
100
Pathophysiology to do with the cardiovascular system itself:
- tissue oedema
- peripheral arterial occlusive disease
- hypertension
