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Valvular heart disease
Sergio Caravita, MD, PhD
Department of Management, Information and Production Engineering, University of Bergamo
Cardiology Unit, IRCCS Istituto Auxologico Italiano San Luca Hospital, Milano
23/03/2020
Heart valves
We have 4 cardiac valves, 2 in the left heart and 2 in the right heart, 2 atrio-ventricularvalves and 2 ventriculo-arterial valves:
- Mitral valve (left heart, separes the left atrium from the left ventricle)
- Aortic valve (left heart, separes the left ventricle from the aorta)
- Tricuspid valve (right heart, separes the right atrium from the right ventricle)
- Pulmonary valve (right heart, separes the right ventricle from the pulmonary artery)
Valves are thought to separe adjacent chambers in distinct phases of the cardiac cycle, allowing proper cardiac function:
- Atrio-ventricular valves are open during ventricular diastole, to allow ventricular fillingand close during ventricular systole
- Ventriculo-arterial valves are open during ventricular systole, to allow aortic and pulmonary blood flow, and close during ventricular diastole
Heart valves
Heart valves
Valvular physiology
Valves are thought to separe adjacent chambers in distinct phases of the cardiaccycle, allowing proper cardiac function:
- Atrio-ventricular valves are open during ventricular diastole, to allow ventricularfilling and close during ventricular systole
- Ventriculo-arterial valves are open during ventricular systole, to allow aortic and pulmonary blood flow, and close during ventricular diastole
When opened, valve orifices are large enough to accomodate increase in flow without generating significant transvalvular gradients (avoiding high pressure in the backward chamber)
When closed, valves are normally continent, even though a minimal regurgitationcan be visualized by modern technology (echocardiography)
Heart valves
2D, 3D and color-Doppler Echocardiography has revolutioned the noninvasiveassessment of cardiac valves
We can visualize and assess the morphology of all the cardiac valves by 2D and 3D echo
We can assess forward and backward flow taking advantage of color-Doppler echo
https://twitter.com/i/status/1237077581339537409
https://twitter.com/i/status/1228009733707255808
https://twitter.com/i/status/1236465300406747136
Valvular diseases
All heart valves can be affected by several pathologic conditions, leading to valve malfunctioning:
- Regurgitation (blood flowing back when the valve should be closed)
- Stenosis (narrowing of the valve orifice obstacling forward blood flow)
- Combination of regurgitation and stenosis
- the left heart is mainly a pressure pump
- the left heart pump blood throughthe high pressure systemiccirculation to several vital organs(systolic function)
- an increase in filling (diastolic) pressure of the left hearttransmittes backward to the lung, promoting pulmonary edema, impairing gas exchange and favoring dyspnea (breathlessness)
- the right heart is mainly a volume pump
- the right heart pump blood throughthe low pressure pulmonarycirculation to the lung for gas exchange, which is maintained evenwith low cardiac output
- An increase in filling pressure of the right heart transmittes backward to the peripheral vein, promoting fluidaccumulation in the recumbent part of the body
This contributes to explain why diseases affecting the right heart (or the right heartvalves), as compared with diseases affecting the left heart (or the left heart valves) can remain asymptomatic for a long time, have generally a slower course, and havebeen neglected by the medical and scientific community for quite a long time.
Keep in mind that:
Manifestations of valvular diseases
Management of valvular heart diseaseThe heart team
Valvular diseases: primary or secondaryregurgitation and stenosis
Primary (regurgitation or stenosis)
- There is a disease primarily affecting the valve or the valve apparatus
Secondary (regurgitation or stenosis)
- There is a disease affecting the cardiac chamber or the arterial vessel, leading to distorsion of the valve or of the valve apparatus
Valvular diseases
Left heart
- Aortic stenosis (frequent in the western world)
- Aortic regurgitation
- Mitral regurgitation
- Mitral stenosis (low frequency in the western world)
Right heart
- Tricuspid regurgitation
Aortic valveThe aortic valve is composed of three semilunar cusps attached to the aortic wall and forming in part, the sinuses of Valsalva.
The highest point of attachment at the leaflet commissures defines the sinotubular junction, and the most ventricular point (i.e., the nadir of the cusps) defines the annular plane.
The coaptation zone of the leaflets (lunulae) are more uniform in thickness except for a slightly more fibrous region at the anatomic midpoint of each cusp or nodules of Arantius.
Aortic stenosisEtiology
Predominant etiology: degenerative, calcific, age-related aortic stenosis
Risk factors: age and classic atherosclerotic risk factors (high cholesterol, diabetes, smoking, hypertension)
Alternative etiologies:
- Congenital malformations predisposing to stenosis (i.e. bicuspid aortic valve disease)
- Rheumatic disease
Bicuspid aortic valve
Two aortic valve cusps instead of three
Higher stress
Abnormalities in aortic flow promoting extracellular matrix dysregulation in aortic wallstructure
Higher risk for valve deterioration (earlier than for degenerative aortic stenosis)
Frequent association with aortic dilatation and aortic valve regurgitation
WSS=wall shear stress
Bicuspid aortic valveanatomical variants
Pathophysiology of aortic stenosis
Aortic stenosis
LV outflowobstruction
Modified from Braunwald textbook of cardiovascular diseases
LV = left ventricle
Pathophysiology of aortic stenosis
Aortic stenosis
LV outflowobstruction
↑ LV systolicpressure
LV hypertrophy, ↑ LV mass
Modified from Braunwald textbook of cardiovascular diseases
CO = cardiac outputLA = left atriumLV = left ventricle
Pathophysiology of aortic stenosis
Aortic stenosis
LV outflowobstruction
↑ LV systolicpressure
LV hypertrophy, ↑ LV mass
LV dysfunction
Modified from Braunwald textbook of cardiovascular diseases
CO = cardiac outputLA = left atriumLV = left ventricle
LV dilation
Pathophysiology of aortic stenosis
Aortic stenosis
LV outflowobstruction
↑ LV systolicpressure
LV hypertrophy, ↑ LV mass
LV dysfunction
↑ LV diastolicpressure
↓ aortic pressure
↓ coronary arteryperfusion pressure
Myocardial ischemia
Myocardial O2
consumption
↓ CO during exerciseand then at rest
↑ LA pressurePulmonary edema
Modified from Braunwald textbook of cardiovascular diseases
CO = cardiac outputLA = left atriumLV = left ventricle
LV dilation
From aortic stenosis to heart failure
Symptoms of aortic stenosis
Myocardial ischemia
↓ CO during exerciseand then at rest
↑ LA pressurePulmonary edema
Modified from Braunwald textbook of cardiovascular diseases
CO = cardiac outputLA = left atriumLV = left ventricle
↑ LV diastolicpressure
Symptoms of aortic stenosis
Fatigue
Myocardial ischemia
Dyspnea
↓ CO during exerciseand then at rest
↑ LA pressurePulmonary edema
Modified from Braunwald textbook of cardiovascular diseases
CO = cardiac outputLA = left atriumLV = left ventricle
Angina
Syncope
DiagnosisEchocardiographyAortic valve
- Valve morphology
- Quantification of the severity of stenosis:
- Orifice planimetric area
- Transvalvular gradient
- Orifice «functional» area
Left ventricle
- Volume
- Geometry (concentric remodeling, concentric hypertrophy, eccentric hypertrophy)
- Systolic function (ejection fraction, deformation «strain» analysis)
- Diastolic function and pulmonary pressure
Ascending aorta
Left atrium
Other valvular diseases
Valve morphology and planimetric areaEchocardiography
Transvalvular pressure gradientEchocardiography
LV systolic functionEchocardiography
Left ventricular ejection fraction
(+/- stroke volume / end-diastolic volume)
Left ventricular global longitudinal strain
(systolic deformation of the left ventricle)
Other exams
Cardiac computed tomography
Quantification of calcium (calcium score)
Precise measures of aortic root and ascending aorta (good spatial resolution)
Anatomical assessment of coronaryarteries
Cardiac magnetic resonance imaging
Valve orifice area
LV volume and geometry
Cardiac catheterization
Measure the hemodynamic alterations
Treatment
Aortic valve replacement
Cardiac surgery (biological or mechanical prosthesis)
Transcatheter aortic valve replacement (biological)
Cardiac surgeryAortic valve replacement
Transcatheter aortic valve implantation/replacement (TAVI / TAVR)
https://www.youtube.com/watch?v=ZkgEf1EvRGc
Aortic regurgitation
Given the anatomy of the aortic valve, AR results from disease of either
- the aortic leaflets (primary AR) and/or
- the aortic root (secondary AR)
that results in valve malcoaptation
Aortic regurgitationetiology
Congenital leaflets abnormalities (bicuspid aortic valve)
Acquired leaflets abnormalities (senile calcifications, infective endocarditis, rheumatic disease, radiation- or toxic- induced valvulopathy)
Acquired aortic root abnormalities (systemic hypertension, idiopathic aortic rootdilatation…)
Congenital aortic root abnormalities
Pathophysiology of aortic regurgitation
Aortic regurgitation
Diastolicregurgitation
↑ LV volume (LV dilation)
↑ LV mass
LV dysfunction
↑ LV strokevolume
↓ effectivestroke volume
↓ myocardial O2
supply
Myocardial ischemia
Myocardial O2
consumption
↓ CO during exerciseand then at rest
Modified from Braunwald textbook of cardiovascular diseases
CO=cardiac outputLA=left atrium
LV=left ventricle
↑ LV end-diastolicpressure
↑ LA pressurePulmonary edema
From aortic regurgitation to heart failure
Hemodynamics of aortic regurgitation
Symptoms of aortic regurgitation
↓ CO during exerciseand then at rest
Modified from Braunwald textbook of cardiovascular diseases
CO=cardiac outputLA=left atrium
LV=left ventricle
↑ LV end-diastolicpressure
↑ LA pressurePulmonary edema
Symptoms of aortic regurgitation
↓ CO during exerciseand then at rest
Modified from Braunwald textbook of cardiovascular diseases
CO=cardiac outputLA=left atrium
↑ LA pressurePulmonary edema
Fatigue
Dyspnea
Diagnosis of aortic regurgitationEchocardiographyAortic valve
- Valve morphology
- Quantification of the severity of regurgitation:
- regurgitant volume
- indirect signs (left ventricular dilatation with pressure overload)
Left ventricle
- Volume
- Geometry (concentric remodeling, concentric hypertrophy, eccentric hypertrophy)
- Systolic function (ejection fraction, deformation «strain» analysis)
- Diastolic function and pulmonary pressure
Ascending aorta
Left atrium
Other valvular diseases
Other exams
Cardiac magnetic resonance imaging
Regurgitant volume
LV volume and geometry
Cardiac catheterization
Hemodynamic alterations pathognomonic of valve disease
Treatment
Aortic valve replacement or repair
Cardiac surgery (repair vs biological or mechanical prosthesis)
Transcatheter aortic valve replacement (biological)
Cardiac surgeryAortic valve replacement
Cardiac surgeryAortic valve repair
Transcatheter aortic valve implantation/replacement (TAVI / TAVR)
Less evidence than for aortic stenosis
Off-label use of approved devices for aortic stenosis in accurately selected patients
Mitral valve
The MV apparatus includes the anterior and posterior mitral leaflets, the mitral annulus, chordae tendinae, papillary muscles, and the underlying LV myocardium.
Mitral regurgitationMechanisms
The mechanism of MR can be divided into two categories, based on whether the mitral leaflets exhibit significant pathological abnormality or not.
In primary MR, an intrinsic abnormality of the leaflets causes the MR, whereas secondary MR results from distortion of the MV apparatus due to LV and/or LA remodeling.
Primary MR
Myxomatous degeneration (mitral valve prolapse)
Fibroelastic deficiency (focal segmental pathology with thin leaflets)
Barlow's disease (diffuse thickening and redundancy, typically affecting multiple segments of both leaflets and chordae)
Secondary MR (atrial or ventricular MR)
The leaflets are intrinsically normal in secondary MR, although minor leaflet thickening and annular calcification can be present
Primary mitral regurgitation
Fibroelastic deficiency is usually seen in individuals older than 60 years.
It is often characterized by single chordal rupture and prolapse of an isolated scallop, most commonly the P2.
The associated mitral regurgitation jet is usually eccentric and directed opposite to the prolapsing scallop.
Barlow’s disease is typically seen in younger patients, 40–60 years old.
It is characterized by excess leaflet tissue.
The leaflets and the chordae appear thickened, redundant and elongated.
Multiple scallops of both anterior and posterior leaflets prolapse or may flail into the left atrium during systole.
These 2 forms of mitral valve prolapse represent the two ends of a spectrum. In clinical practice, most of the patients fall between these two extremes.
Primary MR
Fibroelastic deficiency
https://www-ncbi-nlm-nih-gov.proxy.unimib.it/pmc/articles/PMC6516795/figure/fig-3/
Barlow’s disease
https://www-ncbi-nlm-nih-gov.proxy.unimib.it/pmc/articles/PMC6516795/figure/fig-4/
Secondary mitral regurgitation(ventricular functional regurgitation)
Papillary muscle displacement occurs as a result of global LV enlargement or focal myocardial scarring, and can affect 1 or both papillary muscles, causing posteriorly directed or central MR
Secondary mitral regurgitation
Secondary mitral regurgitation
Secondary regurgitation
Secondary mitral regurgitation(atrial functional regurgitation)
The ventricle has generally normal geometry and ejection fraction
Typically, the atrium is severely enlarged
As opposed to ventricular functional regurgitation in which leaflets show significantly increased tethering, in atrial functional regurgitation the leaflets are usually flattened or only slightly tethered into the LV cavity, and the coaptation point is typically found at the annular plane.
In most of the cases of atrial functional regurgitation, the regurgitation jet is central
Annular and leaflet geometry by 3D echocardiography
Hemodynamics of mitral regurgitation
Acute vs chronic MR
Pressure and/or volume overload
Mitral regurgitation - pathophysiology
Small atrium – high pressure
Large atrium – normal pressure
Diagnosis of mitral regurgitationEchocardiographyMitral valve
- Valve morphology
- Quantification of the severity of regurgitation:
- regurgitant volume
- indirect signs
Left ventricle
- Volume
- Systolic function (ejection fraction, deformation «strain» analysis)
Left atrium and pulmonary pressure
Mitral annulus
Other valvular diseases
Other exams
Cardiac magnetic resonance imaging
Regurgitant volume
LV volume and geometry
Cardiac catheterization
Hemodynamic alterations pathognomonic of valve disease
Treatment
Mitral valve replacement or repair
Cardiac surgery (repair vs biological or mechanical prosthesis)
Transcatheter mitral valve repair
Cardiac surgeryMitral valve replacement
Cardiac surgeryMitral valve repair
Mitral valve repairAlfieri’s stitch
Transcatheter mitral valve repair
https://www.youtube.com/watch?v=FVSzWP77nNo
Mitral stenosis
Mitral stenosisEtiology
Pathophysiology of mitral stenosisFrom mitral regurgitation to heart failure
Symptoms of mitral stenosis
Diagnosis of mitral stenosisEchocardiographyMitral valve
- Valve morphology
- Quantification of the severity of regurgitation:
- regurgitant volume
- indirect signs
Left ventricle
- Volume
- Systolic function (ejection fraction, deformation «strain» analysis)
Left atrium and pulmonary pressure
Other valvular diseases
Valve morphologyEchocardiography
Indirect signsEchocardiography
LV systolic functionEchocardiography
Other exams
Cardiac magnetic resonance imaging
…
…
Cardiac catheterization
Treatment
Mitral valve replacement
Cardiac surgery (repair vs biological or mechanical prosthesis)
Transcatheter ………….
Cardiac surgeryMitral valve replacement
Transcatheter ()
Tricuspid regurgitation
Tricuspid regurgitationEtiology
Pathophysiology of tricuspidregurgitation From tricuspid regurgitation to heart
failure
Symptoms of tricuspid regurgitation
Diagnosis of tricuspid regurgitationEchocardiographyMitral valve
- Valve morphology
- Quantification of the severity of regurgitation:
- regurgitant volume
- indirect signs
Left ventricle
- Volume
- Systolic function (ejection fraction, deformation «strain» analysis)
Left atrium and pulmonary pressure
Other valvular diseases
Valve morphologyEchocardiography
Indirect signsEchocardiography
RV systolic functionEchocardiography
Other exams
Cardiac magnetic resonance imaging
Regurgitant volume
Cardiac catheterization
Treatment
Tricuspid valve replacement
Cardiac surgery (biological prosthesis)
Transcatheter tricuspid valve repair
Cardiac surgeryTricuspid valve replacement
Transcatheter tricuspid valve repair ()
