Structural Heart Disease & Case Studies Flashcards
1
Q
Which two layers of the heart protect the myocardium (muscle layer)?
A
Myocardium is protected on the outside by means of the EPICARDIUM and on the inside by means of the ENDOCARDIUM
2
Q
What process is characteristic of:
a) systole?
b) diastole?
A
a) Contraction
b) Relaxation
3
Q
What phase of the cardiac cycle is longer: systole or diastole?
A
Diastole is slightly longer than systole
Diastole ~2/3 of each heartbeat
Systole ~1/3 of each heartbeat
4
Q
What two volumetric measurements are important for determining the stroke volume or cardiac output of the heart?
A
ESV and EDV
EDV - ESV = SV(mL)
5
Q
What is LV end systolic volume (ESV)?
A
The volume of blood that stays behind in the heart in left ventricle following systole
6
Q
What is LV end diastolic volume (EDV)?
A
The volume of blood in left ventricle just before systole
7
Q
What are the 2 main phases of each heartbeat?
A
- Diastole
2. Systole
8
Q
How many distinct phases can diastole be split into?
A
4
9
Q
How many distinct phases can systole be split into?
A
3
10
Q
How can you calculate the ejection fraction from stroke volume and end diastolic volume?
A
SV/EDV = EF(%)
11
Q
What name can be used to refer to the aortic and pulmonary valves?
A
Semilunar valves
12
Q
What are the 7 stages of the cardiac cycle?
A
- Atrial systole
- Isovolumetric contraction
- Rapid ejection
- Reduced ejection
- Isovolumetric relaxation
- Rapid passive filling
- Reduced passive filling
13
Q
What are structural heart diseases?
A
SHD covers a number of defects which affect the valves and chambers of the heart and aorta
Some defects are present at birth (congenital) while others form later in life (adult; due to damage caused by infections etc.)
14
Q
Name 3 examples of a congenital structural heart disease.
A
Congenital SHDs inc.
- Atrial septal defect (ASD)
- Ventricular septal defect (VSD)
- Coarctation of aorta
- Patent foramen ovale (PFO)
- Patent ductus arteriosus (PDA)
- Tetralogy of Fallot (TOF)
15
Q
What are the two main types of defects that can cause structural heart diseases that form later on in life (i.e. not congenital)?
A
- Valvular dysfunctions (stenosis/regurgitation)
- Muscular defects (cardiomyopathies)
16
Q
Atrial septal defect (ASD) is an example of what type of heart disease?
A
Congenital structural heart disease
17
Q
Ventricular septal defect (VSD) is an example of what type of heart disease?
A
Congenital structural heart disease
18
Q
Coarctation of aorta is an example of what type of heart disease?
A
Congenital structural heart disease
19
Q
Patent foramen ovale (PFO) is an example of what type of heart disease?
A
Congenital structural heart disease
20
Q
Patent ductus arteriosus (PDA) is an example of what type of heart disease?
A
Congenital structural heart disease
21
Q
Tetralogy of Fallot (TOF) is an example of what type of heart disease?
A
Congenital structural heart disease
22
Q
What is ventricular septal defect (VSD)?
A
Congenital structural heart disease
When wall between 2 ventricles fails to develop normally —-> hole in the septal wall
This can cause mixing of oxygenated (oxygen-rich) blood from LV with deoxygenated (oxygen-poor) from RV
23
Q
How might ventricular septal defect (VSD) present in a child?
A
In a child
- Poor weight gain
- Poor feeding, sweating while feeding
- Palpitations
- Shortness of breath
- Fatigue or weakness
- Fast breathing
- Hard breathing
- Pallor
24
Q
What interventions might be needed to treat ventral septal defect (VSD)?
A
If the hole is very large, might require open heart surgery or cardiac catheterisation to manually close it
25
When might no interventions be needed for ventral septal defect (VSD)?
Sometimes the hole is small enough that it closes as the child grows older
26
What is tetralogy of fallot (TOF)?
Congenital structural heart disease
Composed of 4 different defects which occur together:
1. Ventricular septal defect
2. Pulmonary stenosis
3. Widening of aortic valve
4. Right ventricular hypertrophy
27
Explain the 4 defects that occur in tetralogy of fallot (TOF)?
1. Ventricular septal defect
- Hole in heart
2. Pulmonary stenosis
- Pulmonary trunk is narrowed down
3. Widening of aortic valve
- So wide that it can sit on both RV + LV directly allowing mixing of blood/diversion of blood from RV to aorta
- Aortic valve also sits directly on top of this VSD
4. Right ventricular hypertrophy
- Thickening of RV wall
28
Tetralogy of fallot (TOF) is a very critical defect.
What intervention needed is needed and why?
Child must undergo different surgeries
Repair of VSD + repair of too wide aorta
- So child can breathe normally w/o mixing of oxygenated and deoxygenated blood
29
What is atrial septal defect (ASD)?
Congenital structural heart disease
~ to VSD (main difference is that problem is with atrial wall)
When wall between 2 atria fails to develop normally ----> hole in the septal wall
This can cause mixing of oxygenated (oxygen-rich) blood from LA with deoxygenated (oxygen-poor) from RA
30
What interventions might be needed to treat atrial septal defect (ASD)?
Medium to large atrial septal defect diagnosed during childhood or adulthood to prevent further complications
- Cardiac catherisation
- Open heart surgery
31
When might no interventions be needed for atrial septal defect (ASD)?
If hole is small enough that is closes on its own over time
32
When can atrial septal defect (ASD) develop?
In a baby, during pregnancy if the walls between the 2 atria fail to develop properly
33
When is surgery for atrial septal defect (ASD) not recommended?
If you have severe pulmonary hypertension, surgery might worsen condition
34
Why might someone with ASD be given medication?
What kind of medication might they be prescribed?
To help reduce some of the associated signs/symptoms of ASD (medication won't repair the hole)
Medication e.g.
- Beta blockers ----> to keep heartbeat regular
- Anticoagulants ----> to reduce risk of blood clots
35
What valves are most commonly affected in structural heart diseases?
Aortic valve
| Mitral valve
36
What are the most common valvular defects?
Aortic stenosis - narrowing
Aortic regurgitation - incompetence leading to backflow of blood
Mitral stenosis - narrowing
Mitral regurgitation - incompetence of valve, leading to backflow of blood
37
What is coarctation of the aorta?
Congenital structural heart defect
Narrowing of the aortic wall - birth defect in which part of aorta is narrower than rest
38
What are some potential complications that can arise from coarctation of the aorta?
Why are they associated with this condition?
Ventricular hypertrophy
Heart failure
Birth defect - part of aorta narrower than rest
During ventricular systole, blood has to force through this narrow passage
Because of this, ventricle has to work harder to push more blood during each cycle
39
Coarctation of the aorta is very serious and needs urgent repair.
What intervention(s) might be needed to treat this condition?
Intervention depends on severity of condition and age at time of diagnosis
Interventions inc.
Surgery
Balloon angioplasty + stenting
40
Briefly describe the epidemiology of rheumatic heart disease, focusing on sex differences, age differences and overall prevalence.
Conclusions drawn from data (25yo to >=80)
- More prevalent in women than across all age categories
- More prevalent in younger age categories (most prevalent in 25 - 49 = youngest category included in data)
Mostly affects children + adolescents in low and middle income countries
41
Briefly describe the epidemiology of rheumatic heart disease, focusing on sex differences, age differences and overall prevalence.
Conclusions drawn from data in lectures (25yo to >=80)
- More prevalent in women than across all age categories
- More prevalent in younger age categories (most prevalent in 25 - 49 = youngest category included in data)
Mostly affects children + adolescents in low and middle income countries
42
Briefly describe the epidemiology of calcific aortic valve disease, focusing on sex differences, age differences and overall prevalence.
Conclusions drawn from data in lectures (25yo to >=80)
In general
- Increasing prevalence as age increased
- More prevalent in men than women (more similar rates between M/W in older population)
43
Briefly describe the epidemiology of degenerative mitral valve disease, focusing on sex differences, age differences and overall prevalence.
Conclusions drawn from data in lectures (25yo to >=80)
In general
- Increasing prevalence as age increased
- More prevalent in women than men (difference in prevalence increased as age increased)
BUT SOME STUDIES SUGGEST NO DIFFERENCE IN PREVALENCE BETWEEN MEN AND WOMEN
44
Of those that require treatment, what is the most common valvular disease in the US and Europe?
Aortic stenosis (AS)
45
What is the second most frequent cause for cardiac surgery?
Aortic stenosis
46
Aortic stenosis is largely a disease affecting what age group?
Older people - 7th/8th decade of life
47
What condition precedes aortic stenosis?
Aortic sclerosis - can be asymptomatic
48
What is aortic sclerosis?
Defined as aortic valve thickening w/o flow limitation
49
What signs detected in auscultation might suggest aortic stenosis?
Early-peaking, systolic ejection murmur - might hear shrill SEM
Confirmed by ECG
50
What are the risk factors associated with aortic stenosis?
```
Hypertension
LDL levels
Smoking
Elevated C-reactive protein
Congenital bicuspid valves
Chronic kidney disease
Radiotherapy
Older age
```
51
Elevated C-reactive protein is a risk factor of aortic stenosis.
What does elevated CRP suggest?
Why is this significant?
Elevated CRP suggests presence of an active infection in the body
Infection can cause aortic stenosis and valvular damage
52
Congenital bicuspid valves are risk factors of aortic stenosis.
Why?
Valves more prone to wear and tear process and to infections that can cause aortic stenosis
53
Chronic kidney disease is a risk factor of aortic stenosis.
Why?
More exposed and prone to infection
Infections can cause aortic stenosis + valvular damage
54
What are the main causes of aortic stenosis?
1. Rheumatic heart disease
2. Congenital heart disease
3. Calcium build up
55
What is the most common cause of aortic stenosis in developing countries?
Rheumatic heart disease
56
Calcium build up is a potential cause of aortic stenosis.
How?
Calcium build up can occur for various reasons (e.g. dietary reasons, homeostasis problems, etc.)
Can cause aortic sclerosis or calcified aortic walls leading to aortic stenosis in later life
57
Describe the pathophysiology of aortic stenosis.
- Valvular endocardium = damaged due to abnormal blood flow across the valve (in the case of a bicuspid valve) or by an unknown trigger
- Endochardial injury initiates an inflammatory process similar to atherosclerosis and ultimately leads to leaflet fibrosis + deposition of calcium on the valve
- Progressive fibrosis + calcium deposition limit aortic leaflet mobility and eventually produce stenosis
- In rheumatic disease, an autoimmune inflammatory reaction is triggered by prior Streptococcus infection that targets valvular endothelium, leading to inflammation and eventually calcification
58
What initiates the inflammatory process leading to leaflet fibrosis and calcium deposition in the pathophysiology of aortic stenosis?
Endochardial injury
59
What does endocardial injury initiate in the pathophysiology of aortic stenosis?
An inflammatory process, leading to leaflet fibrosis and calcium deposition on the valve
60
What limits aortic leaflet mobility in the pathophysiology of aortic stenosis?
Progressive fibrosis and calcium deposition
61
What results from progressive fibrosis and calcium deposition in the pathophysiology of aortic stenosis?
Limited aortic leaflet mobility and, eventually, stenosis
62
How can aortic stenosis develop in rheumatic disease?
An autoimmune inflammatory reaction is triggered by prior Streptococcus infection that targets valvular endothelium, leading to inflammation and eventually calcification
63
How can aortic stenosis lead to left ventricular hypertrophy?
Stenosis leads to long-standing pressure overload
-----> LVH
64
How can aortic stenosis eventually cause systolic heart failure?
***HINT - AS ----> LVH ----> HF***
Aortic stenosis (AS) leads to long-standing pressure overload -----> LVH
Ventricle maintains a normal wall stress (afterload) despite the pressure overload produced by stenosis
----> As stenosis worsens, adaptive mechanism fails + LV wall stress increases
Systolic function declines as wall stress increases, with resultant systolic heart failure
65
Patient A has aortic stenosis and is found to have developed left ventricular hypertrophy.
How could this result in heart failure, if the stenosis worsens?
Previously, ventricle was maintaining a normal wall stress (afterload) despite the pressure overload produced by stenosis
However, as stenosis worsens, adaptive mechanism fails + LV wall stress increases
66
What might you expect to find in the history/presentation of a patient with aortic stenosis?
- Exertional dyspnoea
- Fatigue
- Chest pain
- Ejection systolic murmur (>=3/6 is present with a crescendo-decrescendo pattern that peaks in mid-systole + radiates to the carotid)
- H/O Rheumatic fever, high lipoprotein, high LDL, CKD, age>65
67
What investigations would you carry out in a suspected case of aortic stenosis?
- Transthoracic echocardiography
- ECG Chest X-Ray (LVH)
- Cardiac catheterisation
- Cardiac MRI
68
For which patients might aortic valve replacement be considered?
- With symptomatic AS
- Asymptomatic patients with severe AS who have an LVEF <50%, or who are undergoing other cardiac surgery
- AVR ? be considered in asymptomatic patients with very severe AS, or severe AS with rapid progression, an abnormal exercise test, or elevated serum B-type natriuretic peptide (BNP) levels
69
What is the primary treatment for symptomatic aortic stenosis?
Aortic valve replacement, AVR
70
For which patients might aortic valve replacement be considered?
- With symptomatic AS
- Asymptomatic patients with severe AS who have an LVEF <50%, or who are undergoing other cardiac surgery
- AVR ? be considered in asymptomatic patients with very severe AS, or severe AS with rapid progression, an abnormal exercise test, or elevated serum B-type natriuretic peptide (BNP) levels
71
Aortic valve replacement might be recommended for patients with asymptomatic aortic stenosis.
What are the requirements for this?
- Asymptomatic patients with severe AS who have an LVEF <50%, or who are undergoing other cardiac surgery
- AVR ? be considered in asymptomatic patients with very severe AS, or severe AS with rapid progression, an abnormal exercise test, or elevated serum B-type natriuretic peptide (BNP) levels
72
What are the options for management of aortic stenosis?
Aortic valve replacement, AVR
Balloon aortic valvuloplasty
Antihypertensive
ACE inhibitors
Statins
73
What types of valves are currently available to be used in aortic valve replacement in aortic stenosis?
Mechanical valves
- Surgical
Bioprosthetic
- Surgical
- Minimally invasive surgical (sutureless)
- Transcatheter aortic valve implantation device
74
What types of valves are under development for use in aortic valve replacement in aortic stenosis?
- Flexible polymeric valve
| - Tissue-engineered heart valve
75
What is aortic regurgitation?
AR is the diastolic leakage of blood from the aorta into the left ventricle
- Not as common as aortic stenosis + mitral regurgitation
76
Why does aortic regurgitation occur?
Occurs due to incompetence of valve leaflets resulting from either intrinsic valve disease or dilation of the aortic root
77
What are the two classifications of aortic regurgitation?
Chronic
Acute
78
What are the main congenital and acquired causes of aortic regurgitation?
Rheumatic heart disease
Infective endocarditis
Aortic valve stenosis
Congenital heart defects
Congenital bicuspid valves
79
What are the main causes (aortic root dilation) of aortic regurgitation?
Marfan's Syndrome
Connective tissue disease/collagen vascular diseases
Idio
Ankylosing spondilytis
Traumatic
80
What can acute aortic regurgitation cause?
A medical emergency, presenting with sudden onset of pulmonary oedema and hypotension or cardiogenic shock
81
Acute aortic regurgitation is a medical emergency.
How does it present?
With sudden onset of pulmonary oedema and hypotension or cardiogenic shock
82
How can we categorise the causes of aortic regurgitation?
1. Congenital & Acquired
| 2. Aortic root dilation
83
Describe the pathophysiology of acute aortic regurgitation.
- Infective endocarditis can lead to rupture of leaflets or even paravalvular leaks
- Vegetations on the valvular cusps can also cause inadequate closure of leaflets, resulting in leakage of blood
- Chest trauma can cause tear in ascending aorta, leading to aortic regurgitation
84
Describe the potential pathophysiology of acute aortic regurgitation.
- Infective endocarditis can lead to rupture of leaflets or even paravalvular leaks
- Vegetations on the valvular cusps can also cause inadequate closure of leaflets, resulting in leakage of blood
- Chest trauma can cause tear in ascending aorta, leading to aortic regurgitation
85
How can infective endocarditis result in acute aortic regurgitation (AR)?
Infective endocarditis can lead to rupture of leaflets or even paravalvular leaks
86
How could vegetations on the valvular cusps lead to acute AR?
Vegetations on the valvular cusps can also cause inadequate closure of leaflets, resulting in leakage of blood
87
How could chest trauma result in acute AR?
Chest trauma can cause tear in ascending aorta, leading to aortic regurgitation
88
What pathophysiology can lead to chronic aortic regurgitation?
- Bicuspid aortic valve
| - Rheumatic fever ----> fibrotic changes causing thickening and retraction of leaflets
89
What pathophysiology can lead to chronic aortic regurgitation?
- Bicuspid aortic valve
| - Rheumatic fever ----> fibrotic changes causing thickening and retraction of leaflets
90
How could rheumatic fever result in chronic AR?
Rheumatic fever ----> fibrotic changes causing thickening and retraction of leaflets
91
Acute aortic regurgitation is a medical emergency and can eventually cause cardiogenic shock.
Describe the mechanism by which this can occur.
1. Acute AR ----> increase blood volume in LV during systole
----->
2. LV end diastolic pressure increases
------>
3. Increase in pulmonary venous pressure
------>
4. Dyspnoea and pulmonary oedema
------->
5. Heart failure
------->
6. Cardiogenic shock
92
Chronic aortic regurgitaion can cause congestive heart failure.
In its later stages, chronic AR can result in ischaemia, necrosis and apoptosis.
Describe the mechanism by which this occurs.
Chronic AR ----> gradually increase in LV volume
-----> LV enlargement and eccentric hypertrophy
Early stages:
1. EF normal or slightly increased -----> after some time, EF falls + LV ESV rises
2. Eventually, LV dyspnoea ----> lower coronary perfusion -----> ischaemia, necrosis + apoptosis
93
What is typical in a history/presentation of acute aortic regurgitation?
- Cardiogenic shock
- Tachycardia
- Cyanosis
- Pulmonary oedema
- Austin glint murmur
94
What is typical in a history/presentation of chronic aortic regurgitation?
- Wide pulse pressure
- Corrigan's pulse (water hammer pulse)
- Pistol shut pulse (Traube sign)
95
What investigations might be carried out in a suspected case of aortic regurgitation?
- Transthoracic echocardiography
- Chest X-Ray
- Cardiac catheterisation
- Cardiac MRI/CT Scan
96
What is the main management option for aortic valve replacement?
Aortic valve replacement, AVR
97
How is acute aortic regurgitation managed?
Ionotropes/vasodilators and valve replacement & repair
98
How is chronic asymptomatic aortic regurgitation managed?
If LV function = normal:
- can be managed by drugs or reassurance
99
How is chronic symptomatic aortic regurgitation managed?
First line - valve replacement with adjunct vasodilator therapy
100
What is key in the management of aortic regurgitation?
Prevention is key
-----> treat rheumatic fever + infective endocarditis with proper protocols and appropriate antibiotics to prevent development of valve defects later on
101
What is mitral stenosis?
Structural heart disease
- Obstruction to left ventricular inflow at the level of mitral valve due to structural abnormality of the mitral valve
(Leading to reduced blood flow from atria to ventricles)
102
What is the main cause of mitral stenosis in developing countries?
Rheumatic fever
103
What can mitral stenosis lead to as the disease progresses?
Pulmonary hypertension ----> right heart failure
104
Name at least 3 potential causes of mitral stenosis.
Causes inc.
- Rheumatic fever
- Carcinoid syndrome
- Use of ergot/serotonergic drugs
- SLE
- Mitral annular calcification due to aging
- Amyloidosis
- Rheumatoid arthritis
- Whipple disease
- Congenital deformity of the valve
105
Describe the pathophysiology of mitral stenosis.
Stenosis of valve typically occurs decades after the episode of acute rheumatic fever
Acute insult (or injury) leads to formation of multiple foci and infiltrates in the endocardium + myocardium and along the walls of the valves
With passage of time, it gets thickened, calcified and contracted resulting in stenosis
106
What causes exertional dyspnoea in the initial stages of mitral stenosis?
Initially, moderate exercise or tachycardia result in exertional dyspnoea due to increased left atrial pressure
107
How can severe mitral stenosis lead to dyspnoea at rest or exertion?
Leads to increase in left atrial pressure, transudation of fluid into the lung interstitium leading to dyspnoea at rest or exertion
108
How does pulmonary hypertension develop in severe mitral stenosis?
Increased left atrial pressure ----> increased backflow pressure into pulmonary veins + ultimately leads to increased pressure in pulmonary vasculature
------> Transudation of fluid or increasing back pressure into pulmonary trunk:
109
Why is cardiac output limited in mitral stenosis?
Narrowing of mitral valve
The restricted orifice limits filling of left ventricle, limiting cardiac output
110
What could haemoptysis occur in severe mitral stenosis?
Haemoptysis could occur if bronchial vein ruptures due to increased pulmonary hypertension or increased back pressure into the pulmonary interstitium
111
What is typical in a history/presentation of mitral stenosis?
- H/O of rheumatic fever
- Dyspnoea
- Orthopnoea
- Diastolic murmur
- Loud P2
- Neck vein distention
- Haemoptysis
- 40-50 yo
112
What investigations might be carried out in a suspected case of mitral stenosis?
- ECG
- Transthoracic echocardiography
- Chest X-Ray
- Cardiac catheterisation
- Cardiac MRI/CT Scan
113
What is the typical management for progressive asymptomatic mitral stenosis?
No therapy required
114
What is the typical management for severe asymptomatic mitral stenosis?
No therapy generally required
Adjuvant balloon valvotomy can be done
115
What is the typical management for severe symptomatic mitral stenosis?
Diuretic
Balloon valvotomy
Valve replacement + repair adjunt
B-blockers
116
What is mitral regurgitation?
= abnormal reversal of blood flow from the LV to the LA
= most frequent valvular heart disease
= caused by the disruption in any part of the mitral valve apparatus
117
If the mitral valve is damaged, it won't close properly/fully.
How will this affect blood flow during systole?
During systole, some of blood flows back into LA
----> Increased LA pressure, etc.
118
How can the causes of mitral regurgitation be categorised?
Acute
Chronic
119
What are the main acute causes of mitral regurgitation?
- Mitral valve prolapse
- Rheumatic heart disease
- Infective endocarditis
- Following valvular surgery
- Prosthetic mitral valve dysfunction
120
What are the main chronic causes of mitral regurgitation?
- Rheumatic heart disease
- SLE
- Scleroderma
- Hypertrophic cardiomyopathy
- Drug related
121
What pathologies are associated with mitral regurgitation caused by infectious endocarditis?
Infectious endocarditis:
- Abscess formation
- Vegetations
- Rupture of chordae tendineae
- Leaflet perforation
122
Chronic mitral regurgitation can lead to left ventricular dysfunction and increased left ventricular end-systolic diameter.
How does this happen?
Progression of CMR leads to eccentric hypertrophy
----> Elongation of myocardial fibres, increased left end diastolic volume, increased preload & decreased afterload
-----> Increase in end-diastolic volume -----> and a decrease in end-systolic volume
Eventually, prolonged (V) overload leads to left ventricular dysfunction and increased left ventricular end-systolic diameter
123
What is typical in a history/presentation of mitral regurgitation?
- Dyspnoea
- Murmur high
- Fatigue
- Orthopnoea
- Chest pain
- Atrial fibrillation
- Diminished S1
- High-pitched, blowing holosystolic murmur
124
What investigations might be carried out in a suspected case of mitral regurgitation?
- ECG
- Transthoracic echocardiography
- Chest X-Ray
- Cardiac catheterisation
- Cardiac MRI/CT Scan
125
What is the typical management for acute mitral regurgitation?
Emergency surgery
Adjunct pre-operative
Diuretics
Adjunct intra-aortic balloon counterpulsation
126
What is the typical management for chronic asymptomatic mitral regurgitation?
1st ACE inhibitors
Beta blockers
If LVEF<60% ----> 1st line = SURGERY
127
What is the typical management for chronic symptomatic mitral regurgitation?
1st SURGERY + medical treatment
If LVEF<30% ----> 1st line = intra-aortic balloon counterpulsation
128
What is cardiomyopathy?
Structural heart disease
A progressive disease of the heart muscle that makes it harder for heart to pump blood to rest of body
Usually irreversible, causes global systolic (contractile) dysfunction with heart failure
Among the most common causes of heart failure
129
What are the 3 main types of cardiomyopathy?
1. Dilated - very enlarged LV
2. Hypertrophic - size of LV essentially reduces
3. Restrictive - stiffness of ventricular wall
130
What is the estimated prevalence of dilated cardiomyopathy?
1:2500
131
What age groups are most commonly associated with dilated cardiomyopathy?
May manifest clinically at a wide range of ages
BUT most commonly occurs in the 3rd or 4th decade of life
132
What can causes of dilated cardiomyopathy be categorised as?
1. Familial - 25% (e.g. genetics, FHx)
2. Primary without family history - idiopathic
3. Secondary
133
What are the main secondary causes of dilated cardiomyopathy?
- Heart valve disease
- After child birth
- Thyroid disease
- Myocarditis
- Alcoholism
- Autoimmune disorders
- Ingestion of drugs
- Mitochondrial disorders
134
What characterises dilated cardiomyopathy?
- Ventricular chamber enlargement
- Systolic dysfunction
- With normal left ventricular wall thickness
135
What is the hallmark gross finding at autopsy in dilated cardiomyopathy?
Left ventricular dilatation, usually > 4cm
136
Familial DCM is a genetic condition.
In rare autosomal dominant inheritance patterns (at least two family members have idiopathic DCM), what is the probability that first degree relatives will inherit the condition?
50% chance
137
How is physiology affected in dilated cardiomyopathy?
- Enlargement of LV
- Lower EF + increase in the ventricular wall stress and ESVs
Early compensatory mechanisms inc.
- An increase in heart rate + tone of the peripheral vascular system because of increased levels of neurohumoral activity
- Neurohumoral activation of the RAAS + an increase in circulating levels of catecholamines
- Levels of natriuretic peptides are also increased
Eventually, these compensatory mechanisms become overwhelmed and the heart fails
138
What are the early compensatory mechanisms that occur in response to dilated cardiomyopathy?
- An increase in heart rate + tone of the peripheral vascular system because of increased levels of neurohumoral activity
- Neurohumoral activation of the RAAS + an increase in circulating levels of catecholamines
- Levels of natriuretic peptides are also increased
139
How are hormone levels affected by the compensatory mechanisms that occur in response to dilated cardiomyopathy?
- Neurohumoral activation of the RAAS + an increase in circulating levels of catecholamines
- Levels of natriuretic peptides are also increased
140
As part of the early compensatory mechanisms that occur in response to DCM, levels of natriuretic peptides increase.
What is the purpose of this?
Helps heart contract more often to eject all blood that's left in the ventricle because of its enlargement
141
Early compensatory mechanisms occur in response to DCM. When these mechanisms get overwhelmed, heart failure can occur.
How might these mechanisms get overwhelmed?
Ventricles become so dilated that they can't contract effectively (fully)
Therefore, can't eject all blood from ventricles into aorta during each systole
Increased (v)-blood accumulated in LV over time ----> LV failure ----> overwhelming of early compensatory mechanisms
142
What happens when the early compensatory mechanisms that occur in response to DCM become overwhelmed?
The heart fails
143
What is typical in a history/presentation of dilated cardiomyopathy?
- Dyspnoea
- Murmur
- Fatigue
- Angina
- Pulmonary congestion
- Low cardiac output
- Displaced apex beat, S3 or systolic
144
What investigations might be carried out in a suspected case of dilated cardiomyopathy?
- Genetic testing
- Viral serology
- ECG
- Chest XR
- Cardiac catheterisation
- Cardiac MR/CT Scan
- Exercise stress test
- Echocardiography
145
What are some of the main target areas for management of DCM?
- Counselling
- Diet modification
- Treatment of underlying conditions
- Treatment of heart failure symptoms
- Treatment of arrhythmias (AF, SVT, VT)
- Treatment of thromboembolic events
146
Why is counselling recommended as part of DCM management?
Usually required because it's a life-long condition
147
What must you consider when deciding management plan for dilated cardiomyopathy?
- Disease
- Symptoms
- Risk factors
- Treatment + side effects
- Exercise tolerance
- Rehabilitation
148
What is an example of diet modification for management of DCM?
Fluid and Na+ restriction
149
What kind of options can be used to treat the underlying condition for management of DCM?
E.G. immunosuppressants for sarcoidosis + myocarditis
E.G. phlebotomy for haemochromatosis
150
How might you treat symptoms of heart failure for management of DCM?
1. ACEi, B-blockers
2. Addition of +/- diuretics +/- angiotensin II receptor antagonists:
- Lower dose of ACEi if patient develops cough, hypotension +/-renal dysfunction
3. If medical treatment = ineffective:
Surgical candidate
- LVAD*
- Orthotopic heart transplantation
Non-surgical candidate
- LVAD*
- Optimise medical management
151
A patient previously diagnosed with DCM has been prescribed ACEi to treat symptoms of heart failure.
Diuretics and ARBs have been added to their protocol.
If this patient develops a cough, hypotension +/ renal dysfunction, what should be done?
Lower dose of ACE inhibitor
152
How might you treat arrhythmias for management of DCM?
1. Amiodarone, Dofetilide
| 2. ICD or CRT
153
How might you treat thrombo-embolic events in management of DCM?
1. Hx previous TE, severe systolic dysfunction or ventricular dilatation
2. Anticoagulants (warfarin)
154
What is hypertrophic cardiomyopathy (HCM)?
Structural heart disease
HCM is a genetic cardiovascular disease
Defined by an increase in LV wall thickness that isn't solely explained by abnormal loading conditions
155
What is HCM defined by?
Defined by an increase in LV wall thickness that isn't solely explained by abnormal loading conditions
156
What is the leading cause of sudden cardiac death in preadolescent and adolescent children?
Hypertrophic cardiomyopathy (HCM)
157
In what proportion of cases does familial HCM occur as an autosomal dominant Mendelian-inherited disease?
50%
158
Most patients with HCM are asymptomatic.
Why is this an issue?
The first clinical manifestation of the disease in such individuals may be sudden death, likely from ventricular tachycardia or fibrillation
159
What is the likely cause of sudden death in someone with HCM?
Likely from ventricular tachycardia or fibrillation
160
What is the hallmark of HCM?
Inappropriate myocardial hypertrophy
- Often asymmetrical
- Occurs in absence of an obvious hypotrophy stimulus
161
What characterises the myocardial hypertrophy that occurs in HCM?
- = inappropriate
- Often asymmetrical
- Occurs in absence of an obvious hypotrophy stimulus
162
1. What region is frequently involved in the hypertrophy that occurs in HCM?
2. How does hypertrophy of this region [1] affect blood flow?
1. Can occur in any region BUT frequently involves interventricular septum
2. Results in an obstruction of flow through LV outflow tract
163
How is physiology abnormal in HCM?
- Abnormal diastolic function
- Abnormal calcium kinetics
- Subendocardial ischaemia
Most patients have abnormal diastolic function
- Impairs ventricular filling & increases filling pressure, despite a normal or small ventricular cavity
These patients h/v abnormal calcium kinetics + subendocardial ischaemia
- Are related to the profound hypertrophy + myopathic process
164
Most patients with HCM have abnormal diastolic function.
What is the impact of this?
Impairs ventricular filling & increases filling pressure, despite a normal or small ventricular cavity
165
What is typical in a history/presentation of hypertrophic cardiomyopathy (HCM)?
- Sudden cardiac death
- Double carotid artery impulse, S3 gallop
- Syncope
- Presyncope
- Congestive heart failure
- Dizziness
- Palpitations
- Angina
- Ejection systolic murmur
166
What investigations might be carried out in a suspected case of hypertrophic cardiomyopathy (HCM)?
Haemoglobin level
- anaemia exacerbates chest pain + dyspnoea
Brain natriuretic peptide (BNP), troponin T levels
- elevated BNP, NT-proBNP, and troponin T levels = associated with a higher risk of cardiovascular events, heart failure + death
Echocardiography
Chest XR
Cardiac MRI
167
What is associated with elevated BNP, NT-proBNP, and troponin T levels?
A higher risk of cardiovascular events, heart failure + death
168
A patient is found to have symptomatic HCM.
What is the first line treatment?
Beta-blockers
169
A patient is found to have symptomatic HCM.
What might prevent this patient from using B-blockers as treatment.
1. Side effects with BBs
| 2. Non-cardiac contraindication to BBs
170
A patient is found to have symptomatic HCM.
This patient was prescribe a beta-blocker but experienced unpleasant side effects and has requested a new drug.
What alternative drug choice can be prescribed in this case?
Verapamil
= calcium channel blocker
(also used instead of BB if patient has non-cardiac contraindication to BB)
171
A patient has symptomatic HCM.
They have been prescribed a beta-blocker as there are no non-cardiac contraindications. They haven't experienced any side effects to this dug.
(If contraindications/side effects, would have been prescribed verapamil)
However, overtime GP has become concerned with their LVOT gradient and persistent symptoms.
1. What can be prescribed next to add to this beta-blocker (or verapamil)?
2. What must be absent in order to prescribe this drug [1]?
1. Add disopyramide
| 2. Must be absence of contraindication to disopyramide (this has to be true AND LVOT gradient AND persistent symptoms)
172
A patient has symptomatic HCM.
They have been prescribed a beta-blocker as there are no non-cardiac contraindications. They haven't experienced any side effects to this dug.
(If contraindications/side effects, would have been prescribed verapamil)
Their GP is now considering adding disopyramide to their prescription.
Why might this be so?
Because of LVOT gradient & persistent symptoms & absence of contraindication to disopyramide
173
A patient has symptomatic HCM.
1. Beta blocker or verapamil
2. Add disopyramide
This patient is showing signs of refractory symptoms.
What is the next step in their management?
Next step = mechanical therapy
174
A patient has symptomatic HCM.
Previous prescriptions:
1. Beta blocker (or verapamil)
2. Add disopyramide
Next appointment:
- Dr suggests mechanical therapy.
Why might this be?
Patient showing refractory symptoms
175
A patient with symptomatic HCM is being prescribed mechanical therapy.
1. What are the two main options?
2. What are the requirements for being eligible for these options?
1. PM with short AV delay
- Existing PM or contraindication to more invasive management
2. Septal myectomy or ablation
- Might change from [1] to [2] if refractory symptoms and NO contraindication to more invasive management
176
What is the general order of the flow diagram for management of symptomatic HCM?
1. B-blocker or verapmil
2. Add disopyramide
3. Mechanical therapy
- PM with short AV delay, or
- Septal myectomy or ablation
177
What is restrictive cardiomyopathy characterised by?
Characterised by diastolic dysfunction with restrictive ventricular physiology
178
Why is restrictive cardiomyopathy a less well-defined cardiomyopathy?
Less well-defined as its diagnosis is based on establishing the presence of a restrictive ventricular filling pattern
179
What causes atrial enlargement in restrictive cardiomyopathy?
Atrial enlargement occurs due to impaired ventricular filling during diastole
180
How are the ventricles typically affected in restrictive cardiomyopathy?
Volume and wall thickness of ventricles usually normal
-----> normal ventricle size/shape + normal contraction BUT stiff muscle
181
What proportion of all cases of diagnosed cardiomyopathies are cases of RCM?
5%
182
How can the causes of RCM be categorised?
1. Idiopathic
2. Familial, e.g.
- has been related to troponin I or desmin mutations
- desmin mutations often in associated with a skeletal myopathy
3. Associated with various systemic disorders, e.g.
- haemochromatosis
- amyloidosis
- Fabry's disease
- carcinoid syndrome
- scleroderma
- anthracycline toxicity
4. Associated with previous radiation
183
Describe the pathophysiology of RCM.
Increased stiffness of myocardium
- due to familial or other secondary causes, e.g. amyloidosis
Infiltrative cardiomyopathy
- characterised by deposition of abnormal substances w/in heart tissue
- infiltration causes ventricular walls to stiffen ----> diastolic dysfunction
Restrictive physiology
- predominated in ealy stages
- causing conduction abnormalities + diastolic heart failure
Adverse remodelling
- may lead to systolic dysfunction + ventricular arrhythmias in advanced cases
184
What are infiltrative cardiomyopathies characterised by?
Characterised by deposition of abnormal substances (i.e. amyloid proteins, non-caseating granulomas, iron) within the heart tissure
185
How does infiltration of the heart tissue affect the ventricles in RCM?
Infiltration causes ventricular walls to stiffen ----> diastolic dysfunction
186
In advanced cases of RCM, what can adverse remodelling lead to?
Systolic dysfunction + ventricular arrhythmias
187
Give an example of a substance that could infiltrate the heart tissue in RCM.
E.G.
- Amyloid proteins
- Non-caseating granulomas
- Iron
188
How is physiology abnormal in RCM?
Increased myocardium stiffness
189
How is physiology abnormal in RCM?
Increased myocardium stiffness
- causes ventricular pressures to rise precipitously w/ small increases in volume
- thus, accentuated filling occurs in early diastole and terminates abruptly at the end of the rapid filling phase
Patients typically have reduced compliance (increased diastolic stiffness), and the LV cannot fill adequately at normal filling pressures
Reduced LV filling volume leads to reduced cardiac output
190
How does increased myocardium stiffness affect ventricular pressure and volume in RCM?
What is the impact of this?
Causes ventricular pressures to rise precipitously w/ small increases in volume
Thus, accentuated filling occurs in early diastole and terminates abruptly at the end of the rapid filling phase
191
How is compliance of heart typically affected in RCM?
What is the impact of this?
Patients typically have reduced compliance (increased diastolic stiffness)
LV cannot fill adequately at normal filling pressures
192
What ultimately leads to a reduced cardiac output in RCM?
Reduced left ventricular filling volume
(Reduced volume occurs as LV cannot fill adequately at normal filling pressures due to reduced compliance (increased diastolic stiffness))
193
What is typical in a history/presentation of restrictive cardiomyopathy (RCM)?
May be more comfortable in sitting position because of fluid in the abdomen or lungs
Frequently h/v ascites + pitting oedema of lower extremities
Liver usually enlarged + full of fluid - ?be painful
Weight loss + cardiac cachexia not uncommon
Easy bruising, Peri-orbital purpura, Macroglossia & Other systemic findings, e.g. carpal tunnel syndrome, should = indication for the clinician to consider amyloidosis
Increased JVP
Pulse volume is decreased - consistent with decreased SV and CO
194
What investigations might be carried out in a suspected case of restrictive cardiomyopathy (RCM)?
- CBC
- Serology
- Amyloidosis check
- Chest XR
- ECG
- Echocardiography
- Catheterisation
- MRI/Biopsy
195
What are the usual treatment options for management of restrictive cardiomyopathy (RCM)?
1. Heart failure medication
Guideline-directed medical therapy for heart failure, inc.
- ACE inhibitors
- ARBs
- Diuretics
- Aldosterone inhibitors
Should be initiated in patients with reduced LV.
2. Anti-arrhythmic therapy
3. Immunosuppression - steroids
4. Pacemaker ( - if heart is beginning to fail and there are multiple conduction abnormalities)
5. Cardiac transplantation
196
Why might a patient with RCM be more comfortable in the sitting position?
Because of fluid in the abdomen or lungs
197
How is the liver usually affected in RCM?
Hepatomegaly, full of fluid
?be painful
198
What should be an indication for the clinician to consider amyloidosis when examining a patient with suspected restrictive cardiomyopathy (RCM)?
Easy bruising
Peri-orbital purpura
Macroglossia
Other systemic findings, e.g. carpal tunnel syndrome
- should = indication for clinician to consider amyloidosis
199
A patient with suspected restrictive cardiomyopathy (RCM) has a decreased pulse volume.
What is this consistent with?
Consistent with decreased stroke volume + cardiac output
200
A patient with RCM has a reduced LV.
What should be initiated in this patient?
Guideline-directed medical therapy for heart failure, inc.
- ACE inhibitors
- ARBs
- Diuretics
- Aldosterone inhibitors
201
What type of medications are included in guideline-directed medical therapy?
- ACE inhibitors
- ARBs (angiotensin receptor II blockers)
- Diuretics
- Aldosterone inhibitors
202
How do you calculate cardiac output?
CO = heart rate (HR) x stroke volume (SV)
SV = EDV - ESV
203
What is cardiac output?
The volume of blood the heart pumps in 1 min
Frequently given in L/min (but can also be given as cm^3/min)
204
What are the usual units given for cardiac output?
Frequently given in L/min (but can also be given as cm^3/min)
205
How do you calculate the ejection fraction?
EF = (SV/EDV) x 100
206
What is the ejection fraction?
The volumetric fraction of blood ejected by the ventricle with each contraction
207
What units are commonly given for ejection fraction?
Commonly given as a % (hence multiplication by 100 in formula for EF)
208
How do you calculate mean arterial pressure?
MAP = (Cardiac output x Systemic vascular resistance) + Central venous pressure
MAP = (CO X SVR) + CVP
OR
At normal resting heart rates:
MAP = Diastolic pressure + 1/3(Systolic pressure - Diastolic pressure)
MAP = DP + 1/3(SP - DP)
209
How can you estimate mean arterial pressure (MAP) at normal resting heart rates?
At normal resting heart rates can estimate MAP using systolic and diastolic pressures:
MAP = DP + 1/3(SP - DP)
210
What is the mean arterial pressure?
MAP is an average arterial blood pressure throughout a single cardiac cycle of systole and diastole
211
What does a MAP >65 mmHg represent, in health?
Represents the pressure necessary to adequately perfuse the body organs
212
How does the estimation of mean arterial pressure change with different levels of activity?
(i.e. at rest vs during exertion)
The estimation of MAP is useable at rest but, during exertion (at high heart rate), MAP moves more closely toward an average of SP and DP
213
Calculate MAP, SV, CO and EF for the following case:
60 yo man
Presented with shortness of breath to A+E
Idea/diagnosis:
- was in type 2 respiratory failure secondary to an infectious exacerbation of COPD
Plan/Actions:
- Needed intensive care support
- Had more invasive monitoring
- A Swan-Ganz catheter was inserted, which measured end diastolic volume as 142ml and end systolic volume as 47 ml.
Observations
- patient was intubated and ventilated using BiPAP of 20/5 with saturations of 95 percent, heart rate 75 beats per minute, respiratory rate 12/minute, blood pressure 115/75mmHg and Temperature 36.5 degrees Celsius.
Work out the mean arterial blood pressure, stroke volume, cardiac output and ejection fraction.
```
MAP = DP + 1/3(SP - DP)
MAP = 75 + 1/3(115 - 75)
MAP = 88.3 mmHg
```
```
SV = EDV - ESV
SV = 142 - 47
SV = 95 ml
```
```
CO = HR x SV
CP = 75 x 95
CO = 7125ml/min or 7.125 L/min
```
```
EF = (SV/EDV) x 100
EF = (95/142) x 100
EF = 66.9%
```
214
21yo man presents to A&E with pyrexia of unknown origin
PMH - nothing of note
- apart from being a known intravenous heroin user
O/E
- HR = 115bpm
- BP = 90/60 mmHg
- Temp = 39oC
- RR = 17 per min
- Sats = 99% on air
- Ausc: early diastolic murmur in left sternal edge which is loudest with the patient sitting forward and at end expiration
- Feet: cellulitis of his distal right leg w/ a deep penetrating ulcer
What is the most likely diagnosis?
Infective endocarditis
215
What is infective endocarditis?
An infection of the endocardium or vascular endothelium of the heart
ENDO - inner lining
CARD - heart
ITIS - inflammation
216
What type of pathogen is usually the cause of infective endocarditis?
Bacteria
IE is typically due to bacteria entering bloodstream + forming a "vegetation" in the endocardium
Streptococci (20-40% of cases) = most common infection
217
How do you diagnose infective endocarditis?
- Fever, malaise, sweats and unexplained weight loss are common symptoms
- May be a new heart murmur o/e
- Blood tests: anaemia, raised inflammatory markers
- Blood cultures: may isolate a micro-organism
- Echo: can show a vegetation, abscess, valve perforation +/ new dehiscence of prosthetic valve
- Echo: often there is regurgitation of the affected valve
- Trans-oesophageal echo: has higher sensitivity vs transthoracic
- LOOK AT DUKE'S CRITERIA
218
According to Duke's criteria, what is the major criteria for diagnosing infective endocarditis?
1. Persistently +ve blood culture for typical organisms
2. ECHO: vegetation, dehiscence of prosthetic valve, abscess
3. New valvular regurgitation murmur
4. Coxiella burnetti infection
219
According to Duke's criteria, what is the minor criteria for diagnosing infective endocarditis?
1. Predisposing heart condition or IV drug use
2. Fever >38C
3. Vascular: emboli to organs, brain
4. Immunologic: glomerulonephritis, Oslers nodes, Roth spots
5. +ve blood cultures that do not meet specific criteria
220
According to Duke's criteria, what is required for a definite diagnosis of endocarditis?
- 2 major clinical criteria
- 1 major + any 3 minor clinical criteria
- 5 minor criteria
- (+ve)gram stain or culture from surgery or autopsy
221
According to Duke's criteria, what is suggestive of possible endocarditis?
- 1 major and >1 minor clinical criteria
| - 3 minor criteria
222
According to Duke's criteria, what rejects a diagnosis of endocarditis?
- Resolution after <4 days antibiotic treatment
- No evidence of infection after surgery
- Definite or possible criteria not met
223
In a patient with infective endocarditis, what features of heart decompensation would you look for?
Symptoms inc.
- shortness of breath
- frequent coughing
- swelling of legs + abdomen
- fatigue
Clinical signs inc.
- raised JVP
- lung crackes
- oedema
224
What part of the heart does infective endocarditis affect?
Explain why.
IE affects endocardium, especially the valves of the heart
IE involves formation of a vegetation at the valves. Vegetation's are bacterial infections surrounded by platelets and fibrin.
It's more common for bacteria to attach to the endocardium if underlying damage is present, and this occurs more frequently at sites of turbulent blood flow such as the valves of the heart
225
What valve is affected most frequently in infective endocarditis?
Aortic valve is affected most frequently
| Aortic > mitral > right-sided valves
226
When is it more common for bacteria to attach to the endocardium?
When there is underlying damage present
227
Why are intravenous drug users at increased risk of infective endocarditis?
Due to repeated injection - potentially exposing their bloodstream to bacteria on the surface of the skin or use of non-sterile needles
Entry of bacteria into bloodstream = first step of IE
228
What is the first and critical step in infective endocarditis?
Entry of bacteria into bloodstream
229
Infective endocarditis can be a complication of what kind of procedures?
Routine surgeries, e.g. dental surgery
230
For which individuals is infective endocarditis more common?
- IV drug users
- Immunosuppressed individuals
- Individuals with congenital heart defects (leading to damaged endocardium)
- Those undergoing routine surgeries
231
25yo man
Presentation
- Palpitations
- Syncope episodes
Investigations
- He has a 24gr Holter monitor: showed that patient was in fast atrial fibrillation for up to 6hrs in the 24hr recording
- TT echo: showed hypokinesia in the inferolateral walls
- Cardiac MRI: confirmed diagnosis of dilated cardiomyopathy (DCM)
What is the definition of dilated cardiomyopathy?
Structural heart disease
DCM is characterised by dilated and thin-walled cardiac chambers with reduced contractility
232
In DCM, how does the dilation of the chambers of the heart affect contractility?
Leads to reduced contractility
233
What are the typical Echo findings in DCM?
- Dilated left ventricle
- Reduced systolic function (ejection fraction)
- Global hypokinesis (typically)
234
25yo man
Presentation
- Palpitations
- Syncope episodes
Investigations
- He has a 24gr Holter monitor: showed that patient was in fast atrial fibrillation for up to 6hrs in the 24hr recording
- TT echo: showed hypokinesia in the inferolateral walls
- Cardiac MRI: confirmed diagnosis of dilated cardiomyopathy (DCM)
What is the definition of dilated cardiomyopathy?
Structural heart disease
DCM is characterised by dilated and thin-walled cardiac chambers with reduced contractility
235
25yo man
Presentation
- Palpitations
- Syncope episodes
Investigations
- He has a 24gr Holter monitor: showed that patient was in fast atrial fibrillation for up to 6hrs in the 24hr recording
- TT echo: showed hypokinesia in the inferolateral walls
- Cardiac MRI: confirmed diagnosis of dilated cardiomyopathy (DCM)
What are the most common causes of dilated cardiomyopathy?
Idiopathic
Genetic
Toxins:
- alcohol
- cardiotoxic chemotherapy
Pregnancy
- peripartum cardiomyopathy
Viral infections
- myocarditis
Tachycardia-related cardiomyopathy
Thyroid disease
Muscular dystrophies
236
25yo man
Presentation
- Palpitations
- Syncope episodes
Investigations
- He has a 24gr Holter monitor: showed that patient was in fast atrial fibrillation for up to 6hrs in the 24hr recording
- TT echo: showed hypokinesia in the inferolateral walls
- Cardiac MRI: confirmed diagnosis of dilated cardiomyopathy (DCM)
How is dilated cardiomyopathy managed?
Medical heart failure therapy:
- ACE inhibitors
- Beta-blockers
- Mineralcorticoid receptor antagonists
Diuretics - for fluid overload
Anticoagulation - for atrial fibrillation
Cardiac devices:
- cardiac resynchronisation therapy
- and/or implantable cardioverter defribrillator (ICD) transplant
237
25yo man
Presentation
- Palpitations
- Syncope episodes
Investigations
- He has a 24gr Holter monitor: showed that patient was in fast atrial fibrillation for up to 6hrs in the 24hr recording
- TT echo: showed hypokinesia in the inferolateral walls
- Cardiac MRI: confirmed diagnosis of dilated cardiomyopathy (DCM)
What will be the implications on this gentleman in the future?
At risk of...
- Heart failure
- Hospitilisation
- Cardiac arrhythmias
- Sudden cardiac death due to ventricular arrhythmia
- Reduced survival
238
A number of genes have been associated with DCM.
1. These associations have frequently been found in genes essential for what processes?
2. These genes affect what 2 structures?
Frequently in genes essential for the formation or effective contraction of heart chambers
Thus either effect myofibril or cellular structure
239
A number of genes have been associated with DCM.
1. These associations have frequently been found in genes essential for what processes?
2. These genes affect what 2 structures?
Frequently in genes essential for the formation or effective contraction of heart chambers
Thus either effect myofibril or cellular structure
240
A number of genes have been associated with DCM, including mutations in genes encoding specific proteins.
What proteins do these genes encode?
Genes encoding cardiac cytoskeletal proteins
241
A number of genes have been associated with DCM, including mutations in genes encoding specific proteins.
What proteins do these genes encode?
Genes encoding cardiac cytoskeletal proteins
242
A number of genes have been associated with DCM, including mutations in genes encoding cardiac cytoskeletal proteins.
Name 2 cardiac cytoskeletal proteins.
E.G.
- Titin
- Lamin
- Phospholamban
- Cardiac myosin binding protein C
- Myosin heavy chain
