Valvular heart disease Flashcards
What are the causes of aortic valve stenosis?
- aortic valve sclerosis -> calcification & fibrosis of leaflets
- bicuspid aortic valve -> congenital valve malformation
- rheumatic fever -> commissural fusion
What is the pathophysiology of aortic valve stenosis?
1- fibrosis & calcification of valve
2- impeded blood flow through valve ————-> murmur/syncope
3- LV contracts harder to push blood against stiff valves
4- high LV-aorta pressure gradient drives blood into aorta to maintain CO (initially)
5- concentric hypertrophy —————————–> angina
6- stiff, hypertrophied LV & high LV pressure makes it harder to fill -> decreased CO (HFpEF)
7- pulmonary congestion ——————————> HF/dyspnea
What are the symptoms of aortic stenosis?
SAD
- Syncope
- Angina
- Dyspnea on exertion (HF like symptoms) orthopnea, PND
What are the clinical features of aortic stenosis?
- Crescendo-decrescendo systolic murmur -> at the 2nd right intercostal space -> radiates to carotid arteries
- handgrip increases intensity of murmur
- valsalva decreases or doesnt change the intensity of the murmur
- soft S2
- S4 if disease if progressive
- pulsus parvus et tardus
- precordial thrill
- early systolic ejection click
How is aortic valve stenosis diagnosed?
ECHO (diagnostic)
- calcification & narrowing of aortic valve
- increased mean aortic pressure gradient & transvalvular velocity
ECG
- signs of LVH (non specific)
CXR
- calcific aortic valve
- enlarged LV
- signs of heart failure
Cardiac catheterization (definitive diagnostic) - used in patients who echo is non-diagnostic
How is aortic valve stenosis managed?
- surgical aortic valve replacement
- transcatheter aortic valve replacement TAVR
What is the age of onset of aortic valve regurgitation?
40-60
- severity increases with age
What are the causes of aortic valve regurgitation?
PRIMARY VALVULAR DEFECT
- congenital bicuspid valve
- calcific aortic valve disease
- rheumatic heart disease
AORTIC DILATATION
- connective tissue disorders (Marfan or Ehlers-Danlos)
- chronic hypertension
- aortitis
- thoracic aortic aneurysm
What is the pathophysiology of acute aortic valve regurgitation?
increased systolic pressure & decreased diastolic pressure
1- LV cant dilate enough in response to regurgitant blood
2- LV end-diastolic pressure increases rapidly
3- pressure transmits backward into pulmonary circulation -> pulmonary edema & dyspnea
- cardiogenic shock & myocardial ischemia if severe
What is the pathophysiology of chronic aortic valve regurgitation?
increased systolic BP & decreased diastolic pressure
1- compensatory increase in stroke volume maintains CO
2- increased left ventricular end-diastolic volume
3- LV enlargement & eccentric hypertrophy
4- left ventricular systolic dysfunction
What are the clinical features of aortic valve regurgitation?
- dyspnea on exertion, PND, orthopnea
- palpitations
- angina
- cyanosis & shock in ACUTE (emergency)
- symptoms of underlying disease (fever in infective endocarditis)
- HIGH PITCHED BLOWING DECRESCENDO DIASTOLIC MURMUR -> heard in the left 3rd & 4th intercostal spaces
- > increases with squatting & handgrip - S3
- widened pulse pressure
- Quincke sign -> visible capillary pulse when pressure applied to fingertips
- De Musset sign -> rhythmic nodding of head in sync with heartbeats
- Corrigan pulse (water-hammer pulse)
- in chronic -> displaced PMI
What are the investigations used to diagnose aortic valve regurg?
ECHO -> dilated aortic root & reversal of blood flow in aorta
XRAY -> to assess pulmonary edema & rule out other causes of dyspnea
- acute AR -> congestion
- chronic AR -> left ventricular hypertrophy + congestion
How is acute aortic valve regurg managed?
- severe acute AR -> surgical treatment ASAP
- medical management of complications
How is chronic aortic regurg managed?
- surgery -> for symptomatic AR & severe asymptomatic AR
- medical management for comorbidities
What is the most common cause of mitral valve stenosis?
rheumatic fever
- onset of symptoms between 20 - 39 years
- impairs blood flow from the left atrium to the left ventricle
What is the pathophysiology of mitral valve stenosis?
1- obstruction of blood flow into the left ventricle (decreased end-diastolic LV volume)
2- decreased SV & cardiac output (forward heart failure)
3- increase in left atrial pressure
4- increased pulmonary capillary pressure -> cardiogenic pulmonary edema
5- pulmonary hypertension -> backward failure & right ventricular hypertrophy
What are the clinical features of mitral valve stenosis?
- dyspnea
- fatigue
- hoarseness
- dysphagia
- palpitations
- mitral facies
- irregular heart rhythm secondary to atrial fibrillation
later stages - symptoms of right heart failure/pulmonary HTN
- paroxysmal nocturnal dyspnea
- orthopnea
- hemoptysis
What will be heard on auscultation of mitral valve stenosis?
- diastolic murmur -> heard at 5th left intercostal space at midclavicular line
- loud S1
- opening snap
What diagnostics are used for mitral valve stenosis?
ECHO -> most important to confirm diagnosis
- left atrial enlargement
- thick calcified mitral valve
- fish mouth appearance of orfice
ECG
- P mitrale: left atrial enlargement
- atrial fibrillation
- right ventricular hypertrophy
XRAY
- left atrial enlargement
How is mitral valve stenosis managed?
- no therapy in asymptomatic patients
- medical therapy in case of mild symptoms -> diuretics for pulmonary congestion & edema -> B blockers to decrease heart rate
- surgical treatment if severe symptoms
What are the causes of mitral valve regurgitation?
PRIMARY MR (organic)
- degenerative mitral valve disease
- rheumatic fever
- infective endocarditis
- ischemic MR
SECONDARY MR (functional) - dilated cardiomyopathy
What is the difference between acute & chronic mitral regurg?
ACUTE
- abrupt elevation of left atrial pressure in setting of normal LA size & compliance
- backflow into pulmonary circulation
- CO decreases due to decreased forward flow
CHRONIC
- gradual elevation of left atrial pressure in the setting of dilated LA & LV
- LV dysfunction occurs due to dilation -> HF
What are the clinical features of mitral valve regurgitation?
- dyspnea on exertion
- PND
- orthopnea
- palpitations
- pulmonary edema
- dry cough
- fatigue
What will be heard on auscultation of mitral valve regurgitation?
HOLOSYSTOLIC MURMUR (high pitched blowing) -> radiates to left axilla & heard best over apex
- > intensity can be increased by increasing preload (leg raise) or afterload (handgrip)
- diminished S1
- S3 gallop
- laterally displaced PMI
How is mitral valve regurg diagnosed?
ECHO
ECG
- acute -> non specific
- chronic -> reflects cardiac remodeling
- left ventricular hypertrophy
- P mitrale
- P pulmonale later in case of right sided strain
How is acute mitral valve regurg managed?
- urgent surgical repair or valve replacement
- any symptoms of heart failure should be managed with medical therapy while waiting for surgery
- > diuretics
- > oxygen
How is chronic mitral valve regurg managed?
- identify & treat underlying cause
- manage heart failure
What is the most common cause of mitral regurgitation in developed countries?
MITRAL VALVE PROLAPSE (MVP) -> structural defect that results in mitral leaflets bulging into left atrium during systole
What are the causes of mitral valve prolapse?
- mostly idiopathic
- connective tissue disorders (Marfan & Ehlers-Danlos syndrome)
- fragile x
- MI
- acute rheumatic heart disease
- IE
- autosomal dominant polycystic kidney disease
What is the pathophysiology of mitral valve prolapse?
myxomatous degeneration of mitral valve due to one of the causes
What are the clinical features of mitral valve prolapse?
- mostly asymptomatic
- in case of complications -> fatigue, dyspnea, cough, syncope, & palpitations
- mitral valve prolapse click (mid-systolic click)
- valsalva maneuver increases murmur & click (decreases LV size)
- squatting decreases them because it increases LV size
What diagnostics are used for mitral valve prolapse & how is it managed?
ECHO
ECG -> normal
- reassurance
Which type of prosthetic heart valves has a lower thrombogenic potential & doesn’t require lifelong anticoagulation?
bio-prosthetic valves
mechanic valves require lifelong anticoagulants
What are the complications of prosthetic heart valves?
- structural valve deterioration
- paravalvular regurgitation
- hemolytic anemia -> with mechanical valves
- infective endocarditis
- valve thrombosis
- thromboembolism -> bleeding
- prosthesis-patient mismatch
Who are the patients that require prophylaxis for dental procedures that involve manipulation of gingival tissue or perforation of the oral mucosa?
Patients with
- prosthetic cardiac valve or prosthetic material for valve repair
- previous infective endocarditis
- unrepaired cyanotic congenital disease
- repaired with prosthetic material or with residual defects at site of patch or device
- cardiac transplant with valve regurg due to structurally abnormal valve
What are the agents used for prophylaxis?
single dose 30-60 mins before procedure
- amoxicillin -> oral
- ampicillin IM or IV -> if patient cant take oral
- cephalexin or clindamycin or azithro/clarithro -> if patient allergic to PCN or AMP
- cefazolin or ceftriaxone/clindamycin IM or IV -> allergic to PCN or AMP & cant take oral
