Echocardiogram (ECHO)
Abstract: Echocardiogram (ECHO) is an essential tool for diagnosis, evaluation, and management of valvular heart disease (VHD). There is an increasing population with valvular heart disease with the advent of advanced medical therapies. The burden of problem is still secondary to rheumatic and degenerative heart disease. In year 2014, the American Heart Association released new guidelines for the management of VHD. They recommend classifying VHD to stages of progression similar to Heart Failure (Table 1). This helps in streamlining the decision making process for patients with VHD. In a patient with VHD it is important to answer these questions in order to make objective decision on whether to intervene or not:
1) Are the symptoms due to VHD? …show more content…
2) How severe is VHD by ECHO?
3) Is there left and/or right ventricle hypertrophy or dilatation?
4) Is there any evidence of pulmonary hypertension?
5) Are there any arrhythmias?
Timing to intervene is critical in VHD. We do not want to intervene early and subject patients to increased risk when they could have had a few more years of quality living or wait too long and risk irreversible damage.
There are 2 main questions to answer in order to assess patients for intervention.
1. When to intervene?
2. How to intervene?
In this update we discuss these issues for all heart valves.
1. Aortic Valve
2. Mitral Valve
3. Tricuspid Valve
4. Pulmonary Valve
1. AORTIC VALVE
A. Aortic Stenosis
Aortic stenosis (AS) is one of the most frequently encountered valvular heart diseases in clinical practice. Calcific AS accounts for the majority of cases in developed countries and rheumatic AS is more common in developing countries (1, 2).
Role of echocardiography and other imaging modalities in evaluation of Aortic Stenosis
a. Two-dimensional echocardiography (2DE) helps in the assessment of anatomy of aortic valve especially number of cusps, degree of calcification and mobility
b. Doppler echocardiography (echo), both pulsed wave (PW) and continuous wave (CW) is used for the assessment of peak transaortic jet velocity, peak and mean gradients, velocity ratio of left ventricular (LV) outflow tract and across the valve and for the measurement of the functional valve area using the continuity equation (3, 4)
Exercise stress echocardiography is used for functional status assessment and risk stratification in patients with asymptomatic severe AS. In patients with LV dysfunction, dobutamine stress echocardiography (DSE) is used for the assessment of severity of AS and contractile reserve. In technically challenging patients, transesophageal echocardiography (TEE) and cardiac computerized tomography (CT) to assess calcification can be used as adjunct to aid in diagnosis. If the clinical and echo evaluations do not correlate, three-dimensional echocardiography (3DE) or occasionally cardiac catheterization can be used to assess the severity of AS. Assessment of severity
The severity of stenosis is classified based on the measurements of the valve area; mean gradient and maximum velocity of the jet. An integrated approach combining various hemodynamic parameters and body surface area has been used to grade the severity (Table 2). Ideally, all parameters should be concordant and in no circumstances single parameter be used alone for grading the severity.
Discordance in assessment (AVA< 50%, if they have abnormal BP response to exercise stress test, scheduled for other cardiac surgeries and are low surgical risk with ∆Vmax > 0.3 m/s per year, Vmax ≥ 5m/s, pulmonary artery systolic pressure ≥ 60mmHg
c. Moderate stenosis with AVA ≤ 1cm2 and Vmax ≥4 m/s during other cardiac surgeries (3, 4)
2. How to intervene?
Apart from clinical symptoms and hemodynamics, risk of operation, patient frailty, life expectancy, and other comorbid conditions help in determining the mode of intervention.
There are various procedures available, risks and benefits of each approach should be discussed in detail before proceeding with the interventions.
1. Surgical aortic valve replacement (SAVR)
2. Transcatheter aortic valve replacement (TAVR)
3. Balloon valvuloplasty
SAVR is the definitive mode of therapy for AS which has shown to improve quality as well as extend life (5). It has an operative mortality of 1-3 % in patients younger than 70 years and 4-8 % in patients aged above 70 years (5, 6). It is recommended in all patients who meet indication for intervention with mild to moderate surgical risk. It is contraindicated in patients with severe comorbidities that would preclude an expected benefit from AV surgery, have shorter life expectancy and high surgical risk (3).
TAVR is an advanced procedure that can be performed in specialized centers with a heart team approach.
It is recommended in patients who have high surgical risk, but meet the indications for Aortic valve replacement (AVR) and have an expected post TAVR survival of >12 months. It is contraindicated in patients with bicuspid/unicuspid/noncalcified aortic valve, acute myocardial infarction (MI), significant coronary artery disease (CAD), an LVEF 25 mm, severe aortic regurgitation or mitral regurgitation, a transient ischemic attack within 6 months, severe renal insufficiency or if the 30-day surgical morbidity and mortality is ≥50% (3, 7, 8).
Balloon valvuloplasty is used in hemodynamically unstable patients as a bridge to SAVR or TAVR in selected patients with severe symptomatic calcific AS or as a palliative measure when surgical risk is high due to comorbidities. It is also indicated in patients with symptomatic severe AS requiring urgent major non-cardiac surgery. There is a 10-20% risk of major complication during valvuloplasty. The hemodynamic and clinical benefit is only transient along with poor long-term outcome (3, 4). …show more content…
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B. Aortic regurgitation
Aortic regurgitation (AR) can be due the disorders of the aortic valve apparatus, which comprises of the aortic leaflets and the annulus or due to disorders affecting the aortic root.
The leaflet disorders include senile leaflet calcifications, infective endocarditis, bicuspid aortic valve and rheumatic fever.
Aortic root causes include idiopathic root dilatation, aortic dissection, Marfan’s syndrome, collagen vascular disease like Ehlers-danlos / Loeys-Dietz syndrome, and syphilis.
AR can be acute or chronic in origin. Acute AR is a rare clinical emergency, which can occur in patients with infective endocarditis or aortic dissection. It can also occur following blunt chest trauma or iatrogenic as a complication of interventional procedures.
Chronic AR are most commonly seen due to rheumatic heart disease, congenital bicuspid valves, and senile or degenerative changes (3, 4).
Role of echocardiography and other modalities in evaluation of Aortic regurgitation
a. 2D ECHO helps in the evaluation of the anatomy of aortic leaflets and the diameters of the aortic root at valve annulus, aortic sinuses, sinotubular junction, and proximal ascending aorta.(9) It also helps to determine left ventricular size and function.
b. Color Doppler is used to measure the proximal AR jet width, flow convergence zone, vena contracta width, and jet turbulence. Effective regurgitant orifice area (EROA) is measured using flow convergence method or PISA. The larger this parameter, the more severe is the AR.
c. PW Doppler is used to assets the diastolic flow reversal in the proximal descending thoracic aorta. Prominent pandiastolic backflow points to severe AR.
d. CW Doppler is used to determine the jet density and the deceleration time (3, 4).
Exercise echo is useful in severe AR and equivocal symptoms and in patients with borderline LV dysfunction (ejection fraction of 50–55%) or end-systolic diameter (equal to or greater than 50 mm/ 25 mm/m2).
TEE is used for the preoperative assessment of the anatomy of leaflets and ascending aorta. It is also used when the transthoracic approach is non-diagnostic or has poor image quality (3, 4).
Cardiac magnetic resonance (MRI), CT and cardiac catheterization are used when the clinical and the echo findings do not correlate and in symptomatic patients with equivocal severity on echocardiographic assessment (3, 4)
Severity
The severity of AR is determined based on various qualitative, semi- quantitative and quantitative parameters of the AR. 3D assessment of vena contracta is also useful in grading the severity of AR. Using these parameters, the American Society of Echocardiography (ASE) has set general guidelines to grade the severity of AR (10). They are summarized in the table 3.
Interventions and indications
1. When to intervene?
a. AVR is highly recommended for symptomatic patients with severe AR regardless of LV systolic function,
b. Asymptomatic patients with chronic severe AR and LV systolic dysfunction (LVEF8 are good candidates for surgery (Table 4). However, the score does not take into account commissural calcification, which may result in valve rupture during valvotomy (13)
Exercise ECHO should be performed in patients with symptoms but moderate MS or asymptomatic patients with severe MS on ECHO (14, 15).
Stages of severity of mitral stenosis are described in Table 5.
Interventions and indications
1. When to Intervene?
a. Severely symptomatic patients (NYHA class III/IV with severe MS (MVA30%
b. Asymptomatic patients with chronic severe primary MR and LV dysfunction (reduced LV EF < 60% and/or LV ESD >40mm)
c. Asymptomatic patients with chronic severe primary MR undergoing other cardiac surgery
d. Moderate and severe MR (both symptomatic and asymptomatic) with LVEF >30% or pulmonary hypertension (PA pressure >50 mmHg) or new onset atrial fibrillation (3, 4)
2. How to intervene?
Mitral valve repair is preferred over mitral valve replacement. Mitral valve replacement is not recommended in isolated MR limited to one half of posterior leaflet unless mitral repair attempt was unsuccessful. (19, 20) If anatomy is unfavorable mitral valve replacement should be performed.
In patients with prohibitive risk for surgery percutaneous mitral valve clip therapy is indicated in symptomatic patients with chronic severe primary MR. (21)
CHRONIC SECONDARY MR
Similar to primary MR, secondary MR also has 3 stages based on its severity (Table 7). Regional wall motion abnormalities, LV systolic dysfunction, annular dilation with loss of coaptation and tethering of mitral valve are the associated cardiac findings.
Interventions and indications
1. When to intervene?
a. MV surgery should be considered in patients with chronic severe secondary MR who are undergoing CABG or aortic valve replacement.
b. Mitral valve surgery may be considered in symptomatic severe secondary MR.
c. Concomitant MV repair may be considered in patients with moderate and severe MR who are undergoing cardiac surgery for other indications.
2. How to intervene?
a. Mitral valve surgery or repair when feasible.
b. Transcutaneous Mitraclip is being used in research setting in patients with chronic secondary MR and LVEF between 20-45%. (3, 4)
3. TRICUSPID VALVE
A. Tricuspid Stenosis
Tricuspid Stenosis (TS) occurs in patients with rheumatic heart disease, carcinoid syndrome, lupus valvulitis, rare congenital malformations, pacemaker induced adhesions and obstruction due to tumors. Tricuspid stenosis is usually accompanied by tricuspid regurgitation (TR) (22, 23).
Role of ECHO in evaluation of Tricuspid Stenosis
a. 2D ECHO defines anatomy of tricuspid valve especially valve thickening and calcification, mobility of leaflets (immobile ‘frozen appearance’ seen in carcinoid syndrome) and leaflet separation.
b. Color Doppler: Narrowing of the diastolic inflow jet and mosaic color dispersion due to turbulence.
c. PW/ CW Doppler: The severity of valve stenosis is assessed by measuring transvalvular pressure gradient, inflow time velocity integral, and pressure half time and valve area (23).
Enlarged right atrium and inferior vena cava are associated findings.
3D ECHO is helpful in identifying anatomical abnormalities of the tricuspid valve leaflets and assessing the orifice area.
Findings in severe tricuspid stenosis
a. Mean pressure gradient > 5 mm Hg
b. Inflow time-velocity integral > 60 cm
c. Pressure half time T 1/2 > 190 ms
d. Valve area < 1.0 cm2
Interventions and indications
1. When to intervene?
a. Tricuspid surgery is recommended for patients with isolated symptomatic severe TS
b. Concomitant tricuspid surgery is recommended in patients with severe TS who are undergoing surgery for left sided valve disease
2. How to intervene?
a. Tricuspid surgery is preferred over balloon tricuspid valvotomy because TS is mostly accompanied by TR and valvotomy can worsen the regurgitation
b. Balloon tricuspid valvotomy might be considered in patients with TS without TR (3, 4, 23)
B. Tricuspid Regurgitation
Tricuspid regurgitation (TR) is most commonly seen after endocarditis, pulmonary hypertension, carcinoid syndrome, adult congenital heart disease and iatrogenic due to pacemaker lead or during RV biopsy.(22)
Role of echocardiography in evaluation of Tricuspid regurgitation
a. 2D echo provides information about the morphology of TV, RA and RV size and function
b. Color Doppler measures TR jet area, vena contracta and EROA
c. Doppler CW/PW measures flow velocity of regurgitation jet and indirectly measures PASP
Systolic hepatic flow reversal is also associated with severe TR.
3D ECHO: TR vena contracta of more than 0.75cm² by 3DE is consistent with severe TR and TR >1.0cm² indicates torrential TR (22, 24).
Stages of severity of tricuspid regurgitation are described in Table 8.
Intervention
1. When to intervene?
a. In patients with symptomatic or asymptomatic severe functional TR at the time of surgical correction of left sided valve lesions
b. In patients with symptomatic severe TR
c. In patients with asymptomatic severe TR with progressive RV dysfunction
2. How to intervene?
a. Valve repair is the preferred surgical treatment, can be a prosthetic annular ring or a biologic annuloplasty repair
b. Valve replacement: It is the procedure of choice when the valve leaflets are so damaged they cannot be corrected by valve repair. (3, 4)
4. PULMONIC VALVE
A. Pulmonary Stenosis
Pulmonary stenosis (PS) is a dynamic or fixed obstruction to the flow of blood from right ventricle to the pulmonary artery. Generally, the level of obstruction is valvular, but rarely it can be supravalvular or subvalvular. It is mostly congenital in origin and is often due to an isolated stenosis of valve (which may be unicuspid, bicuspid, tricuspid or dysplastic) or as a part of congenital heart diseases like tetralogy of fallot, Noonan’s syndrome and Williams’s syndrome. Acquired PS is most commonly due to malignant carcinoid disease and rarely due to rheumatic heart disease, vegetation’s and tumors. (23, 25)
Role of echocardiography in evaluation of pulmonary stenosis
a. 2DE helps in the assessment of the anatomy of pulmonary valve leaflets (number, shape, thickness and mobility) right atrium, right ventricle, pulmonary artery (dimensions and presence of aneurysm, dilatation or narrowing), subvalvular area (infundibular obstruction or hypertrophy) and associated valvular diseases.
b. CW Doppler is used for the assessment of transvalvular gradient, peak and mean pressure gradients
c. Color Doppler is used for the measurement of jet length and jet area.
Color flow mapping and pulse wave Doppler can localize the turbulence precisely and helps to determine the level of obstruction. (3, 4, 23)
Severity
The table summarizes the EAE/ASE recommendations for grading the severity of PS (Table 9)
Interventions and indications
1. When to intervene?
a. In symptomatic patients with a peak and mean Doppler gradient greater than 50 mm Hg and 30 mm Hg respectively
b. In asymptomatic patients with a peak and mean Doppler gradient greater than 60 mm Hg and 40 mm Hg respectively (23)
2. How to intervene?
a. Percutaneous balloon valvotomy is the treatment of choice for patients with PS.
b. Surgical valvotomy is recommended for patients with severe PS which are associated with subvalvular or supravalvular PS, hypoplastic pulmonary annulus or severe pulmonary regurgitation. (23)
In patients who have dysplastic pulmonary valves, associated severe TR or atrial fibrillation (need for a surgical Maze procedure), surgery is preferred (23).
Mechanical valve replacement is rarely performed due the risk of thrombosis (26). However, bioprosthetic valves may be implanted with good durability, although degeneration occurs ultimately (27).
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B. Pulmonary Regurgitation
Pulmonary regurgitation (PR) can be physiological or pathological.
Physiological PR is more common and accounts for 40-78% of patients who have minor degrees of PR without structural abnormalities. Pathological PR may be congenital or acquired. Congenital anomalies account for majority of cases and include bicuspid or quadricuspid valves, leaflet hypoplasia, atretic and myxomatous valve prolapse. Acquired causes include pulmonary hypertension, carcinoid tumors, infective endocarditis, rheumatic heart disease, Marfan’s syndrome and post repair of congenital heart disease or pulmonary stenosis (25).
Role of echocardiography in evaluation of Pulmonary Regurgitation
a. 2DE helps in the evaluation of the number, mobility and the structure of the cusps. It also helps to determine right ventricular size and function.
b. CW/PW Doppler helps to differentiate pathological and physiological PR jets. Pathological PR jet is wider, holodiastolic and longer in duration as compared to the physiological PR jet which is small, central, protodiastolic or mid-diastolic and shorter in duration.
c. 3DE can be used for an accurate assessment of the vena contracta and hence severity of PR.
d. Exercise echo is used only in selected cases of congenital heart disease. It helps to assess RV function under stress and unmasks any latent RV dysfunction (3, 4,
23).
Severity
Quantification of PR severity is not easy as visualization of the valve by echo is difficult. Hence qualitative parameters are used for stratification.
Table 10 summarizes the grading of PR severity (10).
Interventions and indications
1. When to intervene?
a. It is indicated in symptomatic patients with previous valvotomy for pulmonary stenosis and repaired tetralogy of fallot (TOF).
b. It is indicated in symptomatic adults with previous TOF with moderate to severe regurgitation with RV dysfunction or enlargement and/ or sustained ventricular arrhythmias (23).
2. How to intervene?
Pulmonary valve replacement (PVR) is the intervention of choice in patients with severe pulmonary regurgitation. The prosthesis has limited life span and many individuals require a repeat procedure after a few years. Therefore, optimal timing of the surgery is important to balance the need for preserving RV function and avoiding the need for repeat valve replacement (28).
CONCLUSION:
In patients with valvular heart disease it is imperative to diagnose the etiology and severity of the lesion to make recommendations for intervention. 2D Echo has been the gold standard for VHD for a long time, with the advent of 3D Echo and other modalities like CT/Cardiac MRI accurate assessment of VHD should be performed and interventions should be performed in timely manner.
1) Are the symptoms due to VHD? …show more content…
2) How severe is VHD by ECHO?
3) Is there left and/or right ventricle hypertrophy or dilatation?
4) Is there any evidence of pulmonary hypertension?
5) Are there any arrhythmias?
Timing to intervene is critical in VHD. We do not want to intervene early and subject patients to increased risk when they could have had a few more years of quality living or wait too long and risk irreversible damage.
There are 2 main questions to answer in order to assess patients for intervention.
1. When to intervene?
2. How to intervene?
In this update we discuss these issues for all heart valves.
1. Aortic Valve
2. Mitral Valve
3. Tricuspid Valve
4. Pulmonary Valve
1. AORTIC VALVE
A. Aortic Stenosis
Aortic stenosis (AS) is one of the most frequently encountered valvular heart diseases in clinical practice. Calcific AS accounts for the majority of cases in developed countries and rheumatic AS is more common in developing countries (1, 2).
Role of echocardiography and other imaging modalities in evaluation of Aortic Stenosis
a. Two-dimensional echocardiography (2DE) helps in the assessment of anatomy of aortic valve especially number of cusps, degree of calcification and mobility
b. Doppler echocardiography (echo), both pulsed wave (PW) and continuous wave (CW) is used for the assessment of peak transaortic jet velocity, peak and mean gradients, velocity ratio of left ventricular (LV) outflow tract and across the valve and for the measurement of the functional valve area using the continuity equation (3, 4)
Exercise stress echocardiography is used for functional status assessment and risk stratification in patients with asymptomatic severe AS. In patients with LV dysfunction, dobutamine stress echocardiography (DSE) is used for the assessment of severity of AS and contractile reserve. In technically challenging patients, transesophageal echocardiography (TEE) and cardiac computerized tomography (CT) to assess calcification can be used as adjunct to aid in diagnosis. If the clinical and echo evaluations do not correlate, three-dimensional echocardiography (3DE) or occasionally cardiac catheterization can be used to assess the severity of AS. Assessment of severity
The severity of stenosis is classified based on the measurements of the valve area; mean gradient and maximum velocity of the jet. An integrated approach combining various hemodynamic parameters and body surface area has been used to grade the severity (Table 2). Ideally, all parameters should be concordant and in no circumstances single parameter be used alone for grading the severity.
Discordance in assessment (AVA< 50%, if they have abnormal BP response to exercise stress test, scheduled for other cardiac surgeries and are low surgical risk with ∆Vmax > 0.3 m/s per year, Vmax ≥ 5m/s, pulmonary artery systolic pressure ≥ 60mmHg
c. Moderate stenosis with AVA ≤ 1cm2 and Vmax ≥4 m/s during other cardiac surgeries (3, 4)
2. How to intervene?
Apart from clinical symptoms and hemodynamics, risk of operation, patient frailty, life expectancy, and other comorbid conditions help in determining the mode of intervention.
There are various procedures available, risks and benefits of each approach should be discussed in detail before proceeding with the interventions.
1. Surgical aortic valve replacement (SAVR)
2. Transcatheter aortic valve replacement (TAVR)
3. Balloon valvuloplasty
SAVR is the definitive mode of therapy for AS which has shown to improve quality as well as extend life (5). It has an operative mortality of 1-3 % in patients younger than 70 years and 4-8 % in patients aged above 70 years (5, 6). It is recommended in all patients who meet indication for intervention with mild to moderate surgical risk. It is contraindicated in patients with severe comorbidities that would preclude an expected benefit from AV surgery, have shorter life expectancy and high surgical risk (3).
TAVR is an advanced procedure that can be performed in specialized centers with a heart team approach.
It is recommended in patients who have high surgical risk, but meet the indications for Aortic valve replacement (AVR) and have an expected post TAVR survival of >12 months. It is contraindicated in patients with bicuspid/unicuspid/noncalcified aortic valve, acute myocardial infarction (MI), significant coronary artery disease (CAD), an LVEF 25 mm, severe aortic regurgitation or mitral regurgitation, a transient ischemic attack within 6 months, severe renal insufficiency or if the 30-day surgical morbidity and mortality is ≥50% (3, 7, 8).
Balloon valvuloplasty is used in hemodynamically unstable patients as a bridge to SAVR or TAVR in selected patients with severe symptomatic calcific AS or as a palliative measure when surgical risk is high due to comorbidities. It is also indicated in patients with symptomatic severe AS requiring urgent major non-cardiac surgery. There is a 10-20% risk of major complication during valvuloplasty. The hemodynamic and clinical benefit is only transient along with poor long-term outcome (3, 4). …show more content…
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B. Aortic regurgitation
Aortic regurgitation (AR) can be due the disorders of the aortic valve apparatus, which comprises of the aortic leaflets and the annulus or due to disorders affecting the aortic root.
The leaflet disorders include senile leaflet calcifications, infective endocarditis, bicuspid aortic valve and rheumatic fever.
Aortic root causes include idiopathic root dilatation, aortic dissection, Marfan’s syndrome, collagen vascular disease like Ehlers-danlos / Loeys-Dietz syndrome, and syphilis.
AR can be acute or chronic in origin. Acute AR is a rare clinical emergency, which can occur in patients with infective endocarditis or aortic dissection. It can also occur following blunt chest trauma or iatrogenic as a complication of interventional procedures.
Chronic AR are most commonly seen due to rheumatic heart disease, congenital bicuspid valves, and senile or degenerative changes (3, 4).
Role of echocardiography and other modalities in evaluation of Aortic regurgitation
a. 2D ECHO helps in the evaluation of the anatomy of aortic leaflets and the diameters of the aortic root at valve annulus, aortic sinuses, sinotubular junction, and proximal ascending aorta.(9) It also helps to determine left ventricular size and function.
b. Color Doppler is used to measure the proximal AR jet width, flow convergence zone, vena contracta width, and jet turbulence. Effective regurgitant orifice area (EROA) is measured using flow convergence method or PISA. The larger this parameter, the more severe is the AR.
c. PW Doppler is used to assets the diastolic flow reversal in the proximal descending thoracic aorta. Prominent pandiastolic backflow points to severe AR.
d. CW Doppler is used to determine the jet density and the deceleration time (3, 4).
Exercise echo is useful in severe AR and equivocal symptoms and in patients with borderline LV dysfunction (ejection fraction of 50–55%) or end-systolic diameter (equal to or greater than 50 mm/ 25 mm/m2).
TEE is used for the preoperative assessment of the anatomy of leaflets and ascending aorta. It is also used when the transthoracic approach is non-diagnostic or has poor image quality (3, 4).
Cardiac magnetic resonance (MRI), CT and cardiac catheterization are used when the clinical and the echo findings do not correlate and in symptomatic patients with equivocal severity on echocardiographic assessment (3, 4)
Severity
The severity of AR is determined based on various qualitative, semi- quantitative and quantitative parameters of the AR. 3D assessment of vena contracta is also useful in grading the severity of AR. Using these parameters, the American Society of Echocardiography (ASE) has set general guidelines to grade the severity of AR (10). They are summarized in the table 3.
Interventions and indications
1. When to intervene?
a. AVR is highly recommended for symptomatic patients with severe AR regardless of LV systolic function,
b. Asymptomatic patients with chronic severe AR and LV systolic dysfunction (LVEF8 are good candidates for surgery (Table 4). However, the score does not take into account commissural calcification, which may result in valve rupture during valvotomy (13)
Exercise ECHO should be performed in patients with symptoms but moderate MS or asymptomatic patients with severe MS on ECHO (14, 15).
Stages of severity of mitral stenosis are described in Table 5.
Interventions and indications
1. When to Intervene?
a. Severely symptomatic patients (NYHA class III/IV with severe MS (MVA30%
b. Asymptomatic patients with chronic severe primary MR and LV dysfunction (reduced LV EF < 60% and/or LV ESD >40mm)
c. Asymptomatic patients with chronic severe primary MR undergoing other cardiac surgery
d. Moderate and severe MR (both symptomatic and asymptomatic) with LVEF >30% or pulmonary hypertension (PA pressure >50 mmHg) or new onset atrial fibrillation (3, 4)
2. How to intervene?
Mitral valve repair is preferred over mitral valve replacement. Mitral valve replacement is not recommended in isolated MR limited to one half of posterior leaflet unless mitral repair attempt was unsuccessful. (19, 20) If anatomy is unfavorable mitral valve replacement should be performed.
In patients with prohibitive risk for surgery percutaneous mitral valve clip therapy is indicated in symptomatic patients with chronic severe primary MR. (21)
CHRONIC SECONDARY MR
Similar to primary MR, secondary MR also has 3 stages based on its severity (Table 7). Regional wall motion abnormalities, LV systolic dysfunction, annular dilation with loss of coaptation and tethering of mitral valve are the associated cardiac findings.
Interventions and indications
1. When to intervene?
a. MV surgery should be considered in patients with chronic severe secondary MR who are undergoing CABG or aortic valve replacement.
b. Mitral valve surgery may be considered in symptomatic severe secondary MR.
c. Concomitant MV repair may be considered in patients with moderate and severe MR who are undergoing cardiac surgery for other indications.
2. How to intervene?
a. Mitral valve surgery or repair when feasible.
b. Transcutaneous Mitraclip is being used in research setting in patients with chronic secondary MR and LVEF between 20-45%. (3, 4)
3. TRICUSPID VALVE
A. Tricuspid Stenosis
Tricuspid Stenosis (TS) occurs in patients with rheumatic heart disease, carcinoid syndrome, lupus valvulitis, rare congenital malformations, pacemaker induced adhesions and obstruction due to tumors. Tricuspid stenosis is usually accompanied by tricuspid regurgitation (TR) (22, 23).
Role of ECHO in evaluation of Tricuspid Stenosis
a. 2D ECHO defines anatomy of tricuspid valve especially valve thickening and calcification, mobility of leaflets (immobile ‘frozen appearance’ seen in carcinoid syndrome) and leaflet separation.
b. Color Doppler: Narrowing of the diastolic inflow jet and mosaic color dispersion due to turbulence.
c. PW/ CW Doppler: The severity of valve stenosis is assessed by measuring transvalvular pressure gradient, inflow time velocity integral, and pressure half time and valve area (23).
Enlarged right atrium and inferior vena cava are associated findings.
3D ECHO is helpful in identifying anatomical abnormalities of the tricuspid valve leaflets and assessing the orifice area.
Findings in severe tricuspid stenosis
a. Mean pressure gradient > 5 mm Hg
b. Inflow time-velocity integral > 60 cm
c. Pressure half time T 1/2 > 190 ms
d. Valve area < 1.0 cm2
Interventions and indications
1. When to intervene?
a. Tricuspid surgery is recommended for patients with isolated symptomatic severe TS
b. Concomitant tricuspid surgery is recommended in patients with severe TS who are undergoing surgery for left sided valve disease
2. How to intervene?
a. Tricuspid surgery is preferred over balloon tricuspid valvotomy because TS is mostly accompanied by TR and valvotomy can worsen the regurgitation
b. Balloon tricuspid valvotomy might be considered in patients with TS without TR (3, 4, 23)
B. Tricuspid Regurgitation
Tricuspid regurgitation (TR) is most commonly seen after endocarditis, pulmonary hypertension, carcinoid syndrome, adult congenital heart disease and iatrogenic due to pacemaker lead or during RV biopsy.(22)
Role of echocardiography in evaluation of Tricuspid regurgitation
a. 2D echo provides information about the morphology of TV, RA and RV size and function
b. Color Doppler measures TR jet area, vena contracta and EROA
c. Doppler CW/PW measures flow velocity of regurgitation jet and indirectly measures PASP
Systolic hepatic flow reversal is also associated with severe TR.
3D ECHO: TR vena contracta of more than 0.75cm² by 3DE is consistent with severe TR and TR >1.0cm² indicates torrential TR (22, 24).
Stages of severity of tricuspid regurgitation are described in Table 8.
Intervention
1. When to intervene?
a. In patients with symptomatic or asymptomatic severe functional TR at the time of surgical correction of left sided valve lesions
b. In patients with symptomatic severe TR
c. In patients with asymptomatic severe TR with progressive RV dysfunction
2. How to intervene?
a. Valve repair is the preferred surgical treatment, can be a prosthetic annular ring or a biologic annuloplasty repair
b. Valve replacement: It is the procedure of choice when the valve leaflets are so damaged they cannot be corrected by valve repair. (3, 4)
4. PULMONIC VALVE
A. Pulmonary Stenosis
Pulmonary stenosis (PS) is a dynamic or fixed obstruction to the flow of blood from right ventricle to the pulmonary artery. Generally, the level of obstruction is valvular, but rarely it can be supravalvular or subvalvular. It is mostly congenital in origin and is often due to an isolated stenosis of valve (which may be unicuspid, bicuspid, tricuspid or dysplastic) or as a part of congenital heart diseases like tetralogy of fallot, Noonan’s syndrome and Williams’s syndrome. Acquired PS is most commonly due to malignant carcinoid disease and rarely due to rheumatic heart disease, vegetation’s and tumors. (23, 25)
Role of echocardiography in evaluation of pulmonary stenosis
a. 2DE helps in the assessment of the anatomy of pulmonary valve leaflets (number, shape, thickness and mobility) right atrium, right ventricle, pulmonary artery (dimensions and presence of aneurysm, dilatation or narrowing), subvalvular area (infundibular obstruction or hypertrophy) and associated valvular diseases.
b. CW Doppler is used for the assessment of transvalvular gradient, peak and mean pressure gradients
c. Color Doppler is used for the measurement of jet length and jet area.
Color flow mapping and pulse wave Doppler can localize the turbulence precisely and helps to determine the level of obstruction. (3, 4, 23)
Severity
The table summarizes the EAE/ASE recommendations for grading the severity of PS (Table 9)
Interventions and indications
1. When to intervene?
a. In symptomatic patients with a peak and mean Doppler gradient greater than 50 mm Hg and 30 mm Hg respectively
b. In asymptomatic patients with a peak and mean Doppler gradient greater than 60 mm Hg and 40 mm Hg respectively (23)
2. How to intervene?
a. Percutaneous balloon valvotomy is the treatment of choice for patients with PS.
b. Surgical valvotomy is recommended for patients with severe PS which are associated with subvalvular or supravalvular PS, hypoplastic pulmonary annulus or severe pulmonary regurgitation. (23)
In patients who have dysplastic pulmonary valves, associated severe TR or atrial fibrillation (need for a surgical Maze procedure), surgery is preferred (23).
Mechanical valve replacement is rarely performed due the risk of thrombosis (26). However, bioprosthetic valves may be implanted with good durability, although degeneration occurs ultimately (27).
---------------------------------------------------------------------------------------------------------------------
B. Pulmonary Regurgitation
Pulmonary regurgitation (PR) can be physiological or pathological.
Physiological PR is more common and accounts for 40-78% of patients who have minor degrees of PR without structural abnormalities. Pathological PR may be congenital or acquired. Congenital anomalies account for majority of cases and include bicuspid or quadricuspid valves, leaflet hypoplasia, atretic and myxomatous valve prolapse. Acquired causes include pulmonary hypertension, carcinoid tumors, infective endocarditis, rheumatic heart disease, Marfan’s syndrome and post repair of congenital heart disease or pulmonary stenosis (25).
Role of echocardiography in evaluation of Pulmonary Regurgitation
a. 2DE helps in the evaluation of the number, mobility and the structure of the cusps. It also helps to determine right ventricular size and function.
b. CW/PW Doppler helps to differentiate pathological and physiological PR jets. Pathological PR jet is wider, holodiastolic and longer in duration as compared to the physiological PR jet which is small, central, protodiastolic or mid-diastolic and shorter in duration.
c. 3DE can be used for an accurate assessment of the vena contracta and hence severity of PR.
d. Exercise echo is used only in selected cases of congenital heart disease. It helps to assess RV function under stress and unmasks any latent RV dysfunction (3, 4,
23).
Severity
Quantification of PR severity is not easy as visualization of the valve by echo is difficult. Hence qualitative parameters are used for stratification.
Table 10 summarizes the grading of PR severity (10).
Interventions and indications
1. When to intervene?
a. It is indicated in symptomatic patients with previous valvotomy for pulmonary stenosis and repaired tetralogy of fallot (TOF).
b. It is indicated in symptomatic adults with previous TOF with moderate to severe regurgitation with RV dysfunction or enlargement and/ or sustained ventricular arrhythmias (23).
2. How to intervene?
Pulmonary valve replacement (PVR) is the intervention of choice in patients with severe pulmonary regurgitation. The prosthesis has limited life span and many individuals require a repeat procedure after a few years. Therefore, optimal timing of the surgery is important to balance the need for preserving RV function and avoiding the need for repeat valve replacement (28).
CONCLUSION:
In patients with valvular heart disease it is imperative to diagnose the etiology and severity of the lesion to make recommendations for intervention. 2D Echo has been the gold standard for VHD for a long time, with the advent of 3D Echo and other modalities like CT/Cardiac MRI accurate assessment of VHD should be performed and interventions should be performed in timely manner.