structural heart diseases Flashcards
What are the layers of the heart?
myocardium, endocardium inside, epicardium outside
What are the 2 heart sounds?
closure of atrioventricular valves and semi-lunar valves
What is p-wave? T wave? Qrs?
p - atrial depolarisation
qrs - ventricular depolarisation
t-ventricular repolarisation
Why atrial contraction? How much does it usually contribute to filling of ventricle and when does this change
Atrial contraction to top up after passive filling. Usually contributes 10% but more during exercise, or when heart beat increases
What is end-systolic volume? End-diastolic volume? Stroke volume?
End-systolic volume is volume left in LV after systole. End-diastolic volume is volume in LV before ejection. Stroke volume is end-diastolic volume - end-systolic volume
What are some congenital structural heart diseases?
Ventricular septal defect, atrial septal defect, tetralogy of fallot, aortic coarctation
What types of conditions can develop later in life?
Mitral/aortic stenosis/regurgitation, cardiomyopathies
What is Ventricular septal defect VSD? What does this cause? What might it present with? If large hole what may be needed?
- VSD is when there is a hole in the ventricular septum and thus mixing of deoxy and oxy blood. Due to the pressure differences between LV and RV, oxygenated blood goes into the RV to go to the lungs, creating an increased pressure in pulmonary system and less oxygenated blood to the tissues
- presents with poor weight gain, feeding, palpitations. -Sometimes the hole closes after birth but for large holes may need surgery or cardiac catheterisation to close the hole
What is tetralogy of fallot? What is needed and why?
- VSD. 2. pulmonary stenosis 3. misplaced aorta due to widening of aortic valve 4. RV hypertrophy. Require surgeries for repair to prevent mixing of deoxy and oxy blood
What is atrial septal defect?
Hole between the 2 atria
What is coarctation of aorta? What does this lead to ? What is needed?
Coarctation (narrowing) of the descending aorta and therefore heart has to pump blood at a higher pressure and work harder to pump against narrow aorta (ventricular hypertrophy/heart failure.
-needs urgent repair
What are the 3 things that can lead to valvular defects and how common are they worldwide, age and gender wise?
Rheumatic fever common in developing countries. Calcific aortic disease - above 70 equal sexes. Degenerative mitral valve diseases - 70 -more in females.
What is more prevalent: aortic or mitral disease?
Mitral more prevalent than aortic
What is aortic stenosis preceded by?
aortic sclerosis (aortic valve thickening)
What are risk factors for aortic stenosis?
Hypertension, dyslipidaemia, smoking, congenital bicuspid valves (more prone to infections leading to stenosis), CKD, old age, radiotherapy
What are causes of aortic stenosis?
Rheumatic heart disease, congenital heart disease, calcium problems or calcification of valve
What is the pathophysiology behind aortic stenosis?
The valvular endocardium is damaged due to abnormal blood flow across the valve or another trigger and this endocardial injury leads to leaflet fibrosis and calcification causing thickening of the valve and inability for it to open completely during systole. In rheumatic disease, previous streproccocal infection targets the valvular endocardium leading to inflammation and therefore calcification
How does rheumatic disease cause aortic stenosis?
previous streprococcal infection targets valvular endocardium leading to inflammation and thus calcification/fibrosis so valve cant open all the way in systole (sclerosis & stenosis)
How does this abnormal physiology lead to problems in aortic stenosis?
Fibrosis and calcification lead to stenosis as the valve cannot open completely during systole to pump blood into the aorta/body. This increases the pressure that the LV must pump with leading to left ventricular hypertrophy in order to compensate. Can lead to left ventricular failure. Systolic function declines.
What is the history and presentation of aortic stenosis?
Chest pain, exertional dyspnoea, ejection systolic murmur with crescendo de crescendo pattern that peaks in mid-systole and radiates to the carotid. High LDL, CKD
What are investigations done in aortic stenosis?
Transthoracic echocardiography, ECG
What is management of aortic stenosis? What are options for treatment and at what stage?
Aortic valve replacement. Asymptomatic patients with severe AS LVEF <50% or undergoing other cardiac surgery. Or asymptomatic with severe or rapid progression, abnormal exercise test or high serum BNP levels. Other surgeries are balloon aortic valvuloplasty, ACE inhibitors, statins
What is aortic regurgitation and what can cause it?
failure of the aortic valve to close completely leading to backflow of blood into the left ventricle during diastole. It can be caused by incompetence of the valve leaflets due to fibrosis or other diseases or due to aortic root dilation/dissection.
Is aortic regurgitation chronic?
Can be acute or chronic. Acute is a medical emergency (Pulmonary hypertension/oedema, cardiogenic shock) or chronic
What are causes of aortic regurgitation?
Rheumatic heart disease, infective endocarditis, aortic valve stenosis which can lead to regurgitation later, bicuspid aortic valves, aortic root dilation
How does aortic root dilation/aneurysm cause AR and what are causes of aortic root dilation?
Aortic root dilation pulls the leaflets apart so they cannot close properly during diastole. This can be due to connective tissue disorders like marfan’s syndrome, or idiopathic.
What is pathophysiology of acute aortic regurgitation?
Infective endocarditis leads to rupture of the leaflets and vegetations (masses) on the valvular cusps can cause inadequate closure. Chest trauma can also cause tear in aorta leading to AR
What is pathophysiology of chronic aortic regurgitation?
Rheumatic fever can cause fibrosis/calcification of the leaflets and inadequate closure
What is abnormal physiology cause in acute aortic regurgitation?
Inadequate closure of the valves during diastole means that blood flows back into the left ventricle. The LV end-diastolic pressure increases, which causes increased LV pressure. The increased LV pressure means there is increase in pulmonary venous pressure due to the backflow which can lead to dyspnoea and pulmonary oedema - leading to heart failure and cardiogenic shock
hat is abnormal physiology of chronic aortic regurgitation?
In chronic aortic regurgitation, this increase in LV end-diastolic pressure causes eccentric hypertrophy but after some time there is failure to compensate and therefore ejection fraction falls and LV end-systolic volume rises. Too much blood to pump and not enough pressure and therefore failure in pumping leads to ischaemia, LV dyspnoea, lower coronary perfusion, necrosis/apoptosis
How does acute AR present?
Pulmonary hypertension, pulmonary oedema, cardiogenic shock, tachycardia, cyanosis, austin flint murmur (mid-diastolic murmur)
How does chronic AR present?
Chronic AR presents with a wide pulse pressure (because diastolic pressure of the aorta decreases as blood flows back to LV, but systolic increases as there is more blood to pump), corrigan (wide hammer pulse) and pistol shot pulse (traube sign)
What are investigations for AR?
Transthoracic echocardiography, chest X ray, ECG, MRI /CT, cardiac cathetarisation
Management of acute AR?
Treat the underlying cause and inotropes (to increase strength of muscle contractions + vasodilators. valve replacement/repair.
Management of chronic AR in each condition?
If asymptomatic and LV function ok then drugs + reassurance. If causes problems valve replacement with adjuvant vasodilator therapy
How to prevent AR from happening
Treatment of rheuamatic fever and infective endocarditis to prevent valve problems
What is mitral stenosis and what does it cause?
Mitral stenosis is when the mitral valve cannot open properly during diastole and therefore there is decreased filling of the LV from the LA.it can cause pulmonary hypertension and right heart failure
What are causes of mitral stenosis?
Rheumatic fever, carcinoid syndrome, drugs, SLE, amyloidosis
What is pathophysiology behind mitral stenosis?
Stenosis of the valve due to rheumatoid fever. With time, thickening and calcification leading to stensosis.
What is the abnormal physiology cause in mitral stenosis and why?
Calcification means that less blood flows into the LV and stays into LA. This causes an increase in atrial pressure which then causes backflow into pulmonary system leading to exertional dyspnoea. Severe stenosis leads to increase n left atrial pressure leading to pulmonary oedema and thus dyspnoea. Pulmonary hypertension can happen too. There is limited filling of LV and thus limitedd cardiac output. Haemoptysis if back pressure causes the bronchial veins to rupture
What do they present with in mitral stenosis
Rheuamtic fever, dyspnoea, orthopneoa, , diastolic murmur, haemoptysis, neck vein distension
Investigations for mitral stenosis?
ECG, transthoracic echocardiography, chest x ray, cardiac cathetarisation, cardiac MRI/CT scan
What is management for mitral stenosis in each case?
If progressive asymptomatic no therapy needed. If severe asymptomatic can do adjuvant balloon valvotomy. If severe symptomatic use diuretics, beta blockeres and balloon vavlvotomy or valve replacement & repair
What is mitral regurgitation?
When the mitral valve cannot close completely during systole and there is backflow of blood from the LV to LA.
What are causes of acute mitral regurgitation?
Mitral valve prolapse, rheumatic heart disease, infective endocarditis, valvular surgery, prosthetic mitral valve dysfunction
What are chronic causes of mitral regurgitation
Rheuamatic heart disease, SLE, hypertrophic cardiomyopathy, drug related
What is the pathophysiology of mitral regurgitation?
Infective endocarditis leads to abscess formation, vegetations and rupture to the chordae tendinae and thus leaflet perforation. In chronic there is backflow of blood from LV to LA, but the blood needs to go back into the LV. Therefore there is increase in volume in both LV and LA. This leads to eccentric hypertrophy. There is increased preload and decreased afterload so increase in end-diastolic volume and decrease in end-systolic volume. Prolonged volume overload leads to LV dysfunction
What is presentation of mitral regurgitation?
Dyspnoea, orthopnea, chest pain, atrial fibrillation, holosystolic murmur (entire systole)
Investigations mitral regurgitation?
ECG, transthoracic echocardiography, chest x ray, cardiac cathetarisation, cardiac MRI/CT
Management of acute MR? chronic MR?
acute - emergency surgery with pre-operative diuretics and intra-aortic balloon counterpulsation. Chronic asymptomatic (Ace inhibitors, beta blockers, if EJ <60% surgery. If symptomatic surgery + meds. If LV EJ< 30 intra-aortic balloon counterpulsation
What are cardiomyopathies?
Disease of heart muscle making it harder to pump
What is dilated cardiomyopathy and what does it cause?
Dilated cardiomyopathy is when there is abnormal dilation of ventricular chamber with normal LV thickness. This causes systolic contractile dysfunction (because walls cant pump as much)
What are the causes of dilated cardiomyopathy
Familal DCM - autosomal dominant, other causes include heart valve disease, child birth, thyroid disease, alcoholism, autoimmune conditions
What is pathophysiology of dilated cardiomyopathy?
Ventriuclar chambers enlarged and systolic dyfunction.
Familial DCM inheritance?
autosomal dominant. at least 2 family members have DCM, first degree relatives have 50% chance of inheriting)
hat is the abnormal physiology of dilated cardiopathy and what molecule levels are high?
In dilated there is enlargement of LV with normal wall thickeness, this increases wall stress and lowers the ejection fraction (therefore increasing the end-systolic volume as more blood left inside). To compensate, there will be increase in heart rate and tone of peripheral vascular system due to renin-angiogentin system increasing catecholamines and natriuretic peptides. But eventually these fail and we get LV failure
What is presentation of dilated cardiomyopathy?
resents with dyspnoea, displaced apex beat, systolic murmur, fatigue, angina, pulmonary congestion, low cardiac output
What are investigations for dilated cardiomyopathy?
Genetic testing, viral serology to rule out endocarditis and all the rest
What is management of dilated cardiomyopathy?
Counselling, symptoms, risk factors, lifestyle diet modificiation, sodium & fluid retention treat underlying condition (endocarditis, sarcoidosis). Diuretics, ACE inhibitors, beta blockers (transplant) if heart failure symptoms
What is the eotiology of hypertrophic cardiomyopathy?
Increase in LV wall thickness but not explained by abnormal loading conditions.
what does hypertrophic cardiomyopathy cause sudden death from?
Causes sudden death in young people often due to ventricular fibrillation/tachycardia.
What is the pathophysiology of hypertrophic cardiomyopathy?
Inappropriate often assymetrical myocardial hypertrophy without hypertrophy stimulus. In LV and often includes intraventricular septum blocking the outflow tract into the aorta and therefore affecting blood outflow. Because the muscle is big and abnormal it is stiff and has less compliance leading to decreased ventricular filling. Output impaired as well so cant keep up with outlfow (have abnormal calcium kinetics and subendocardial ischaemia).
What is presentation of hypertrophic cardiomyopathy
Sudden cardiac death, double carotid artery pulse (bifid pulse), syncope, ejection systolic murmur, palpitations, dizziness
What investigations for hypertrophic cardiomyopathy?
Heamoglobin level, BNP, troponin T, associated with higher risk of CV events
What is management for HCM?
With symptoms - beta blockers, if side effects switch to verapamil, add disopyramide and mechanical therapy. Paceemaker or assisted device or remove septum with surgery (septal myectomy or septal ablation)
What is restrictive cardiomyopathy?
Myocardium in LV is more stiff but normal thickness leading to less compliance and impaired filling (diastolic dysfunction) but systolic function remains normal. Due to impaired filling of the ventricle, we get atrial impairment.
What are causes of restrictive cardiomyopathy?
Can be idiopathic or familial or associated with disorders like amyloidosis, sarcoidosis, heamochromatosis, or radiation (they deposit into the tissue stiffening it)
What is pathophysiology of restrictive cardiomyopathies
Increased stifness. Deposition of abnornal substances causing heart tissue to stiffnes leading to diastolic disunfction causing dysfunction in filling. Can cause conduction abnormalities and diastolic heart fialure. LV cant properly fill ledaing to reduced cardiac output
how does restrictive cardiomyopathy lead to reduced cardiac output
Because LV reduced filling so less going out
What is the presentation of restrictive cardiomyopathies?
Pitting oedema, enlarged liver, weight loss/cachexia, (easy bruising, periorbital pupura, macrogralosia, carpal tunnel (amyloidosis)), increased jugular venous pressure, pulse volume decreased
What is management of restrictive cardiomyopathies?
ACE inhibitors, ARB, diuretics, aldosterone inhibitors, arrhythmic therapy, steroids, cardiac transplant
