Valvular Heart Disease Flashcards
Sites of auscultation of the heart valves:
What is the most common vascular heart disease?
Aortic stenosis
What substance is responsible for the mechanical integrity of a valve?
Collagen is responsible for the mechanical integrity of a valve.
What role do interstitial cells have in heart valves?
The valve is populated throughout by interstitial cells, which produce and continuously repair the extracellular matrix (especially collagen), allowing the valve to respond and adapt to changing mechanical conditions.
Valves of the heart
Summarise valve stenosis:
- Stenosis is the failure of a valve to open completely, which impedes forward flow.
- Usually chronic and therefore well tolerated.
- Pressure overload.
Summarise regurgitation.
Regurgitation results from failure of a valve to close completely, thereby allowing reversed flow. • Can be chronic or acute • Volume overload.
Pathologic changes of valves are largely of three types:
- Damage to collagen that weakens the leaflets, eg. mitral valve prolapse.
- Nodular calcification beginning in interstitial cells, as in calcific AS.
- Fibrotic thickening, the key feature in rheumatic heart disease.
A systolic ejection murmur is a sign of what?
Aortic stenosis
Pressure volume loops reflecting valvular disease:
What are the three leaflets of the aortic valve?
Left
Right
Posterior
What causes aortic stenosis?
Usually caused by mechanical stress over time, which damages endothelial cells around the valves, causing fibrosis and calcification, which hardens the valve and makes it more difficult to open completely.
Aortic stenosis is most commonly seen in which population?
Patients over 60 years old.
What are the main risk factors of aortic stenosis?
Age
Bicuspid aortic valve (congenital abnormality).
Chronic rheumatic fever.
Chronic rheumatic fever
Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection.
How does chronic rheumatic fever cause aortic stenosis?
Causes chronic inflammation and repair, leading to fibrosis. In this case, the leaflets can fuse together, called commissural fusion.
What change to the heart occurs as a result of aortic stenosis?
Concentric hypertrophy of the left ventricle.
- in response to the higher pressure need to pump blood through the aortic stenosis.
What are the complications of aortic stenosis?
Developing heart failure.
Microangiopathic hemolytic anemia.
- reduction in blood flow to organs, decreased perfusion to different organs = different presentation of symptoms.
e. g:
decreased perfusion to the brain = syncope.
decreased perfusion to the heart = angina.
Microangiopathic hemolytic anemia
Damage to red blood cells as they’re forced through the smaller valve, splitting them into smaller fragments called schistocytes. This leads to hemoglobinuria, which is hemoglobin in the urine.
What is the treatment for aortic stenosis?
Replacement of the valve.
What are the symptoms of aortic stenosis?
Syncope
Angina
Dyspnoea
Aortic stenosis = SAD
What are the signs of aortic stenosis?
Slow rising pulse.
Narrow pulse pressure.
Soft S2
ESM (crescendodecrescendo)
Gallivardin phenomenon
Radiates to carotids
Heaving apex beat
How is aortic stenosis diagnosed?
ECG
CXR
Echocardiogram
When does aortic regurgitation occur?
Ventricular diastole
What are the causes of aortic regurgitation?
Aortic root dilation - (This is when the root dilates, or gets bigger, and in doing so pulls apart the leaflets, making it harder for the valves to fit snugly together and close all the way, letting some blood flow backward).
Infective endocarditis damaging the valves (causes fibrosis).
Chronic rheumatic fever (causes fibrosis).
What causes aortic root dilation?
Aortic dissection
Aneurysm
Syphilis
What causes chronic rheumatic fever to develop?
The disease typically develops two to four weeks after a streptococcal throat infection.
What type of murmur is heard in aortic regurgitation?
Early decrescendo diastolic murmur, caused by the blood flowing back through the valve.
How is blood pressure altered in aortic regurgiation?
Because blood is leaking back from the aorta into the left ventricle, the left ventricular blood volume increases, which increases the stroke volume, or the amount of blood that the left ventricle pumps out during contraction, or systole. More blood pumped out of the heart per squeeze requires more pressure, so systolic blood pressure increases. During diastole, though, there’s less blood volume in the aorta because some has leaked back into the ventricle, which means that diastolic blood pressure decreases.
Pulse pressure =
Pulse pressure = systolic pressure - diastolic pressure
How does a large pulse pressure present?
A large pulse pressure, meaning a large difference between systolic and diastolic pressure, is referred to as a hyperdynamic circulation. Patients with a hyperdynamic circulation have bounding pulses, or water-hammer pulses, because the blood, which is mostly composed of water, slams like a hammer against the walls of the arteries with each heartbeat.
What change occurs to the heart due to aortic regurgitation?
Eccentric ventricular hypertrophy.
What are the symptoms of aortic regurgitation?
Dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnoea
What are the signs of aortic regurgitation?
Collapsing pulse
Wide pulse pressure
Soft S1
Austin-flint murmur
Austin-flint murmur
Austin Flint murmur is a low-pitched rumbling heart murmur which is best heard at the cardiac apex.
What are the two leaflets of the mitral valve?
Anterior
Posterior
What is the most common cause of mitral valve regurgiation?
Mitral valve prolapse
What structures normally prevent the valves from regurgitating?
Papillary muscles and chorda tendiniae
What causes mitral valve prolapse?
With mitral valve prolapse, the connective tissue of the leaflets and surrounding tissue are weakened; this is called myxomatous degeneration. Why this happens isn’t well understood, but it is sometimes associated with connective tissue disorders, such as Marfan syndrome and Ehlers-Danlos syndrome. Myxomatous degeneration results in a larger valve leaflet area and elongation of the chordae tendineae, which can sometimes rupture; this rupture typically happens to the chordae tendineae on the posterior leaflet, and can cause the posterior leaflet to fold up into the left atrium.
Ehlers–Danlos syndromes
Ehlers–Danlos syndromes (EDS) are a group of genetic connective tissue disorders. Symptoms may include loose joints, joint pain, stretchy skin, and abnormal scar formation.
Complications may include aortic dissection, joint dislocations, scoliosis, chronic pain, or early osteoarthritis.
What type of murmur can be heart with mitral regurgitation?
Classic heart murmur that includes a mid-systolic click, which is sometimes followed by a systolic murmur.
Tends to be holosystolic (lasts for the duration of systole).
What can cause mitral valve regurgitation?
Mitral valve prolapse.
Damage to the papillary muscles due to a heart attack.
Left sided heart failure, due to the left ventricular dilation that occurs as a result.
Chronic rheumatic fever (causes leaflet fibrosis).
Infective endocarditis.
What are the complications of mitral regurgitation?
Mitral regurgitation can cause left side heart failure.
LV Cardiomyopathy
MI
How does mitral regurgitation cause left side heart failure?
Mitral regurgitation leads to increased preload in the left ventricle.
- this causes both the left atrium and left ventricle to experience volume overload. This results in the left side of the heart undergoing eccentric hypertrophy.
Cardiomyopathy
A disease of the heart muscle that makes it harder for your heart to pump blood to the rest of your body. Cardiomyopathy can lead to heart failure. The main types of cardiomyopathyinclude dilated, hypertrophic and restrictivecardiomyopathy
What are the symptoms of mitral valve regurgitation?
- Dyspnoea
- Orthopnoea
- Paroxysmal Nocturnal Dyspnoea (PND)
- Hypotension
Paroxysmal nocturnal dyspnoea
Paroxysmal nocturnal dyspnea or paroxysmal nocturnal dyspnoea (PND) is an attack of severeshortness of breath and coughing that generally occur at night. It usually awakens the person from sleep, and may be quite frightening.
What are the signs of mitral regurgitation?
- Pulses paradoxus
- Irregular irregular pulse
- Soft S1, S3
- Pan systolic murmur radiates to apex
- Displaced apex beat
- Thrill
- Respiratory crepitations
- Peripheral oedema
What are the main causes of mitral stenosis?
- Rheumatic fever
- Calcification
- Carcinoid
- Congenital
What effect does mitral stenosis have on the chambers of the heart?
Dilation of the LA LV and RV.
What are the symptoms of mitral valve stenosis?
- Fatigue
- Dyspnoea
- Orthopnoea
- PND
- Hoarse voice
- Haemoptysis
What are the signs of mitral valve stenosis?
- AF
- Malar flush
- Loud S1
- Mild diastolic murmur
- Loud S2
- RV heave
- Ascites
- Peripheral oedema
What type of murmur is heard in mitral stenosis?
Mild diastolic murmur
How does mitral stenosis causes pulmonary oedema?
A constant elevation in both blood volume and pressure in the left atrium causes it to dilate, and can allow blood to back up into the pulmonary circulation; this causes pulmonary congestion and pulmonary edema, which can lead to symptoms like dyspnea, or difficulty breathing.
How can mitral stenosis lead to right sided heart failure?
The extra blood volume causes higher pressures in the pulmonary circulation, or pulmonary hypertension, which can ultimately make it harder for the right ventricle to pump blood to the lungs. Therefore, over time the right ventricle can hypertrophy and ultimately fail, which is called right-sided heart failure.
How can mitral stenosis cause atrial fibrilation and increase risk of clotting?
When the left atrium dilates, the muscle walls stretch and the pacemaker cells that run through the walls become more irritable, which increases the risk of atrial fibrillation. During atrial fibrillation, the right and left atrium don’t contract properly anymore, causing more blood to stagnate. Since the left atrium is already pretty dilated, static pools of blood can become a major risk for thrombus formation, and if a blood clot forms, it can immediately get into the systemic circulation.
What problems can dilation of the left atrium cause?
Obstruct the oesophagus causing dysphagia.
Atrial fibrilation by stretching and irritating pacemaker cells.
What is the treatment for mitral stenosis?
Medications: Anticoagulation and beta blockers.
Intervention: Balloon valvotomy or surgery.
What can cause tricuspid regurgitation?
Endocarditis
Chronic rheumatic fever
Carcinoid
Ebsteins
What are the symptoms of tricuspid regurgitation?
Dyspnoea
Peripheral oedema
What are the signs of tricuspid regurgitation?
- CV wave of JVP
- RV heave
- PSM at LSE
- Loud P2
- Peripheral oedema
- Ascites
What are three leaflets of the tricuspid valve?
Medial
Posterior
Septal
How does pulmonary hypertension cause tricuspid regurgitation?
Tricuspid regurgitation can be caused by pulmonary hypertension which causes an increase in right ventricular pressure. This pressure then dilates the tricuspid valve, allowing blood to go backward
Ebstein anomaly
Ebstein’s anomaly, which is when a person is born with leaflets that are located too low, i.e. in the ventricle rather than between the atria and the ventricle, and this makes it hard for the leaflets to form a nice seal.
How does tricuspid regurgitation affect the chambers of the heart?
Right ventricular hypertrophy.
What is the main complication of triscupid regurgitation?
Right-sided heart failure, which causes symptoms like distended neck veins, swelling of the ankles and feet, and blood backed up to the liver, which causes hepatosplenomegaly, or swelling of the liver and spleen.
How does tricuspid stenosis affect the chambers of the heart?
Right atrium dilation
What is the complication caused by right atrial dilation in tricuspid stenosis?
When the right atrium dilates, the muscle walls stretch and the pacemaker cells that run through these walls become more irritable, which increases the risk of arrhythmias like atrial flutter and atrial fibrillation.
What is the major complication of tricuspid stenosis?
Right-sided heart failure, which causes symptoms like distended neck veins, swelling of the ankles and feet, and blood backed up to the liver, which causes hepatosplenomegaly, or swelling of the liver and spleen.
(same as tricuspid regurgitation)
What leaflets make up the pulmonary valve?
Anterior
Left
Right
What are the causes of pulmonary stenosis?
Congenital
Noonans syndrome
Tetrology of Fallot
Fibrosis
What murmur is heard in pulmonary stenosis?
Systolic murmur with a click
What complications can occur because of pulmonary stenosis?
Right heart failure
Microangiopathic haemolytic anemia
What are the causes of pulmonary valve regurgitation?
Infections and surgeries
Endocarditis
Inflammation of the inner layer of the heart.
How does non-bacterial thrombotic endocarditis occur?
Turbulence of bloodflow causes damage to the endocardial lining. This damage exposes the underlying collagen and tissue factor, causing platelets and fibrin to adhere, which forms this tiny thrombosis or blood clot. This is called Nonbacterial Thrombotic Endocarditis, or NBTE.
Why are valves commonly affected in endocarditis?
Due to the turbulent blood flow damaging the endothelial lining at the valves.
What are common causes of endocarditis?
Drug use (infected needle)
Dental/Surgery
Open wound
What are the symptoms of infective endocarditis?
Fever
Murmur
Sepsis
Splinter hemorrhages
Janeway lesions (red patches on hand)
Osler’s nodes
An Austin Flint murmur is as a consequence of which of the following pathologies:
- A) Mitral valve prolapse of the posterior leaflet causing anteriorly directed mitral regurgitation causing a pansystolic murmur
- B) Mitral stenosis from a rheumatic aeitiology causing a late diastolic murmur
- C) Aortic regurgitation causing a mid diastolic murmur from displacement of the anterior mitral valve leaflet
- D) Ventricular septal defect causing a pansystolic murmur
C) Aortic regurgitation causing a mid diastolic murmur from displacement of the anterior mitral valve leaflet.
Malar flush
Malar flush is a plum-red discolouration of the high cheeks classically associated with mitral stenosis due to the resulting CO2 retention and its vasodilatory effects. It can also be associated with other conditions, such as SLE or polycythemia rubra vera.
What is the difference between atrial fibrilation and atrial flutter?
In atrial fibrillation, the atria beat irregularly. In atrial flutter, the atria beat regularly, but faster than usual and more often than the ventricles, so you may have four atrialbeats to every one ventricular beat.
Malar flush is seen in what conditions?
Mitral stenosis
Polycythaemia
A wide pulse pressure e.g 163/58mmHg is indicative of what vavular disease?
Aortic regurgitation
