Valvular diseases Flashcards
Normal aortic valve area?
3-4 cm2
What is aortic stenosis
obstruction of blood flow across the aortic valve due to pathological narrowing.
RFs for aortic stenosis
- Hypercholesterolaemia
- Hypertension
- Smoking
- Diabetes
- Rheumatic heart disease
How many valves does the normal aortic valve have?
Tricuspid
Types of congenital aortic stenosis?
Congenital aortic stenosis
Congenital bicuspid valve
Types of aortic stenosis?
Supravalvular
Subvalvular
Valvular
How does congenital aortic stenosis work?
Happen in unicuspid, bicuspid, tricuspid valve
Associated with aortic coarctation, dissection or aneurysm
Symptoms shown in 30s to 50s
When do symptoms of aortic stenosis occur?
Symptoms occur when valve area is 1/4th of normal.
What does aortic valve look like normally?
Closed - Mercedez logo
open - hole
If theres fusion of the tricuspid valve what can you get?
BAV - bicuspid aortic valve
BAV symptoms:
0.5-2% of general population
Up to 10% of first degree relatives will have BAV
Associated aortopathy and coarctation
Aortic valve normally
The aortic valve is normally made up of three leaflets: the left, the right, and the posterior leaflet. It opens during systole to allow blood to be ejected to the body. During diastole, it closes to allow the heart to fill with blood and get ready for another systole.
What is the pathophysiology of aortic stenosis?
Smaller valve - dont open as easily - LV contracts creates high pressure pushing on valve until it snaps open - “ejection click”
Blood flows through narrower opening - creates murmur - louder as blood flows pas opening and quierer as it subsides - crescendo decrescendo
LV generates higher pressure - undergoes concenctric hypertrophy - still enough blood may not leave heart - lead to HF
What is the presentation of aortic stenosis?
Syncope: (exertional) 15%
Angina: (increased myocardial oxygen demand; demand/supply mismatch) 35%
Dyspnoea: on exertion due to heart failure (systolic and diastolic) 50%
Sudden death <2%
What are the physical signs of aortic stenosis?
Slow rising carotid pulse (pulsus tardus) & decreased pulse amplitude (pulsus parvus)
Ejection click
Heart sounds- soft or absent second heart sound, S4 gallop due to LVH - As valve becomes narrower second heart sound gets softer and softer and eventually goes away - murmur
Ejection systolic murmur- crescendo-decrescendo character.
“Loudness” does NOT tell you anything about severity
Symptoms of aortic stenosis
- Fatigue
- Shortness of breath
- Angina
- Dizziness
- Fainting
Natural history of aortic stenosis:
Mild AS to Severe AS:
8% in 10 years
22% in 22 years
38% in 25 years
The onset of symptoms is an indication of poor prognosis if left untreated.
What is the prognosis of AS?
Angina + AS: 50% survive for 5 years.
Syncope + AS: 50% survive for 3 years,
HF + AS mean survival is <2 years.
Risk of Sudden Cardiac Death in asymptomatic or minimally symptomatic patients is rare (<2%).
How do we investigate aortic stenosis?
Echocardiography
Two measurements obtained are:
Left ventricular size and function: LVH, Dilation, and EF
Doppler derived gradient and valve area (AVA)
Severity of AS:
mild: AVA >1.5cm2 Velocity 2.6-3m/s
moderate: 1-1.5cm2 3-4m/s
Severe: <1cm2 >4m/s
What is the management for AS?
General:
Fastidious dental hygiene / care
Consider IE prophylaxis in dental procedures
Medical - limited role since AS is a mechanical problem. Vasodilators are relatively contraindicated in severe AS
Aortic Valve Replacement:
Surgical
TAVI – Transcatheter Aortic Valve Implantation
What is TAVI?
TAVI – Transcatheter Aortic Valve Implantation
Pass balloon into damaged aortic valve – pass new valve through the aorta to sit above the old valve to put a new valve in – not an operation – is a PCI
When do we intervene with AS?
Any SYMPTOMATIC patient with severe AS (includes symptoms with exercise)
Any patient with decreasing EF
Any patient undergoing CABG with moderate or severe AS
Consider intervention if adverse features on exercise testing in asymptomatic patients with severe AS
What is chronic mitral regurgitation (CMR)?
Backflow of blood from the LV to the LA during systole
Mild (physiological) MR is seen in 80% of normal individuals.
RFs of CMR
- Fatigue
- Shortness of breath
- Angina
- Dizziness
- Fainting
Causes of CMR:
- MVP
- Ischemic MR
- Rheumatic heart disease
- Infective Endocarditis
- Damage post MI
- Dilated + hypertrophic cardiomyopathies
- Left sided HF
Mitral valve physiology
The mitral valve has two leaflets: the anterior leaflet and the posterior leaflet. Together, they separate the left atrium from the left ventricle. During systole the valve closes, which means blood is ejected out of the aortic valve and into circulation. During diastole, the mitral valve opens and lets blood fill into the ventricle.
The mitral valve is supported by papillary muscles and chordae tendinae.
Pathophysiology of CMR
Mitral regurgitation refers to when the mitral valve doesn’t completely shut allowing blood to leak back into the left atria from the left ventricle.
What does CMR cause?
PURE VOLUME OVERLOAD
Compensatory Mechanisms: Left atrial enlargement, LVH and increased contractility
-Progressive left atrial dilation and right ventricular dysfunction due to pulmonary hypertension.
-Progressive left ventricular volume overload leads to dilatation and progressive heart failure.
Physical signs of CMR?
Pansystolic murmur at the apex radiating to the axilla
Mid systolic click
Soft S1
Additional S3 sound
Tachycardia
Heart Failure: May coincide with increased hemodynamic burden e.g., pregnancy, infection or atrial fibrillation
Symptoms of CMR
- Dyspnoea and orthopnoea: due to pulmonary hypertension
- Fatigue and malaise: due to reduced cardiac output
- Palpitations: due to initial compensation and increased stroke volume
- Peripheral oedema:
What is the natural history of CMR?
Compensatory phase: 10-15 years
Patients with asymptomatic severe MR have a 5%/year mortality rate
Once the patient’s EF becomes <60% and/or becomes symptomatic, mortality rises sharply
Mortality: From progressive dyspnoea and heart failure
What are the investigations you take in CMR?
ECG: May show, LA enlargement, atrial fibrillation and LV hypertrophy with severe MR
Chest XRay: LA enlargement, central pulmonary artery enlargement.
ECHO: Estimation of LA, LV size and function. Valve structure assessment
TOE v helpful
What medications do we use to manage CMR?
Rate control for atrial fibrillation with B-blockers, CCB, digoxin
Anticoagulation in atrial fibrillation and flutter
Nitrates / Diuretics in acute MR
Chronic HF Rx if chronic MR with CCF
No indication for ‘prophylactic’ vasodilators such as ACEI, hydralazine
What do we use for the management of CMR other than medication?
Serial Echocardiography:
Mild: 2-3 years
Moderate: 1-2 years
Severe: 6-12 months
IE prophylaxis: Patients with prosthetic valves or a Hx of IE for dental procedures.
When is it time for surgery with CMR?
ANY Symptoms at rest or exercise (repair if feasible)
Asymptomatic:
If EF <60%, LVESD >40mm
If new onset atrial fibrillation/raised PAP >50 mmHg
Complications of CMR
- Left sided heart failure
- Pulmonary congestion, hypertension and right sided heart failure: in acute MR
- Cardiogenic shock: as cardiac output isn’t maintained
- Atrial fibrillation:
What is aortic regurgitation?
Leakage of blood into LV during diastole due to ineffective coaptation of the aortic cusps
What are the causes of chronic aortic regurgitation (CAR)?
Bicuspid aortic valve
Rheumatic
Infective endocarditis
What is the pathophysiology of AR?
Combined pressure AND volume overload
Compensatory Mechanisms: LV dilation, Left ventricular hypertrophy. Progressive dilation leads to heart failure
What do you find on the physical exams for AR?
Wide pulse pressure: most sensitive
Hyperdynamic and displaced apical impulse
Auscultation-
Diastolic blowing murmur at the left sternal border
Austin flint murmur (apex): Regurgitant jet impinges on anterior MVL causing it to vibrate
Systolic ejection murmur: due to increased flow across the aortic valve
What is the natural history of AR?
Asymptomatic until 4th or 5th decade
Rate of Progression: 4-6% per year
Progressive Symptoms include:
Dyspnoea: exertional, orthopnea, and paroxsymal nocturnal dyspnea
Palpitations: due to increased force of contraction and ectopics
How can we evaluate AR?
CXR: enlarged cardiac silhouette and aortic root enlargement
ECHO: Allows evaluation of the AV and aortic root with measurements of LV dimensions and function (cornerstone for decision making and follow up evaluation)
How do we manage AR?
General: consider IE prophylaxis
Medical: Vasodilators (ACEI’s potentially improve stroke volume and reduce regurgitation but indicated only in CCF or HTN
Serial Echocardiograms: to monitor progression.
Surgical Treatment: Definitive Tx
What are the indications of surgery in AR?
ANY Symptoms at rest or exercise
Asymptomatic treatment if:
EF drops below 50% or LV becomes dilated > 50mm at end systole
What is mitral stenosis (MS)?
Obstruction of LV inflow that prevents proper filling of ventricle during diastole due to thickness of mitral valve
What is the normal mitral valve area?
4-6 cm2
When do transmitral gradients and symptoms begin?
areas less than 2 cm2
What is the predominant cause of mitral stenosis?
Rheumatic carditis
decreasing due to a reduction of rheumatic heart disease.
What are the causes of mitral stenosis?
Rheumatic heart disease: 77-99% of all cases
Infective endocarditis: 3.3%
Mitral annular calcification: 2.7%
After this flashcard look at slide 59 onwards of the valvular heart disease powerpoint
What is the pathophysiolog of MS?
Progressive Dyspnea (70%): LA dilation > pulmonary congestion (reduced emptying)
-worse with exercise, fever, tachycardia, and pregnancy
Increased Transmitral Pressures: Leads to left atrial enlargement and atrial fibrillation.
Right heart failure symptoms: due to Pulmonary venous HTN
Hemoptysis: due to rupture of bronchial vessels due to elevated pulmonary pressure
What is the natural history of MS?
Mild MS: 10 years after initial RHD insult
Moderate: 10 years later
Severe: 10 years later
What is the mortality of MS due to?
Due to progressive pulmonary congestion, infection, and thromboembolism.
What are the physical signs of mitral stenosis?
prominent “a” wave in jugular venous pulsations: Due to pulmonary hypertension and right ventricular hypertrophy
Signs of right-sided heart failure: in advanced disease
Mitral facies: When MS is severe and the cardiac output is diminished, there is vasoconstriction, resulting in pinkish-purple patches on the cheeks
What are the heart sounds of ms?
Diastolic murmur:
Low-pitched diastolic rumble most prominent at the apex.
Heard best with the patient lying on the left side in held expiration
Intensity of the diastolic murmur does not correlate with the severity of the stenosis
How do we evaluate MS?
ECG: may show atrial fibrillation and LA enlargement
CXR: LA enlargement and pulmonary congestion. Occasionally calcified MV
ECHO: The GOLD STANDARD for diagnosis. Asses mitral valve mobility, gradient and mitral valve area
What is the medical management of MS?
Medications: MS like AS is a mechanical problem and medical therapy does not prevent progression
B-blockers, CCBs, Digoxin which control heart rate and hence prolong diastole for improved diastolic filling
Duiretics for fluid overload
How else can you manage MS?
Serial echocardiography:
Mild: 3-5 years
Moderate:1-2 years
Severe: yearly
What are the indications for mitral valve replacement?
ANY SYMPTOMATIC Patient with NYHA Class III or IV Symptoms
Asymptomatic moderate or Severe MS with a pliable valve suitable for PMBV
