Sandbox: Pulmonary Valve regurgitation
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Aravind Kuchkuntla, M.B.B.S[2]
Synonyms and related terms: Pulmonary Insufficiency, Pulmonary Incompetence, Pulmonary Valve Regurgitation, Pulmonary Regurgitation, Pulmonary Valve Incompetence.
Overview
Isolated pulmonary valve reguritation is a rare disease, it is usually associated with other congenital heart disease. PR usually occurs in patients who have underwent corrective surgery for tetralogy of Fallot or pulmonary valve stenosis. Mild PR is identified in 40 to 70% of patients with normal pulmonary valve and is clinically insignificant. Chronic severe PR usally presents with exercise intolerance and features of right heart failure with progression of the disease. If left untreated patients develop RV failure, arrythmias and sudden cardiac death. Echocardiography is the initial imaging modality to detect and quantify the severity of PR. CMR is the gold standard to study the morphology of the pulmonary valve, RVOT and the RV systolic function. Chronic significant PR is treated with pulmonary valve replacement. Timing of the surgery is an important prognostic factor determining the prognosis.
Historical Perspective
- The pulmonary valve and its function of allowing blood to the lungs for nourishment was first described by Hippocrates.[1]
- Erasistratus, mentioned the involvement of the pulmonary valve in the unidirectional flow.[1]
- Galen described the membranes of the valves and named them as "semilunar".[1]
- Mondino de Luzzi designed the sketch of the pulmonary valves in the anatomical position for the first time.[1]
- Realdo Colombo described the pulmonary circulation for the first time.[1]
Epidemiology and Demographics
- The prevalence of mild pulmonary regurgutation is present in 40% to 78% of patients with normal pulmonary valve anatomy.[2][3][4]
- In patients born with congenital heart disease, 20% of patients have associated abnormalities of the pulmonary valve or the right ventricular outlet obstruction.[2]
- There is increased prevalence of pulmonary regurgitation with increasing age.[2][4]
- There is no racial or ethnic predilection for pulmonary regurgitation.
Classification
Pulmonary valve is classified into the following types based on the morphology of the valve and severity of the disease:
Based on the Pulmonary Valve Morphology
Pulmonary Regurgitation is classified into primary and secondary types based on the involvement of the pulmonary Valve.
- Primary Pulmonary Regurgitation:The pulmonary valve morphology is affected. Isolated PR is very rare and is most commonly associated with other congenital heart diseases.[5]
- Secondary or Functional Pulmonary Regurgitation: The pulmonary valve function is normal. Conditions such as pulmonary hypertension and PA aneursym cause dilation of the valve annulus leading to regurgitation.[6]
Based on the Severity
Pulmonary regurgitation is classified into three categories based on the severity of the regurgitant jet demonstrated on the 2D echo.[7]
- Mild: Normal valve morphology and usually asymptomatic
- Moderate: Normal to abnormal valve morphology with mild symptoms
- Severe: Abnormal valve morphology with significant symptomatology
Natural History, Prognosis, Complications
Natural History
- Mild PR is a very common finding on 2D echo.[8]
- Majority of patients with mild PR are asymptomatic and have a beningn course, not progressing to chronic PR.
- Patients tolerate severe chronic PR for a long period of time and begin to develop symptoms when the right ventricle function begins to decline.
- Chronic severe PR leads to progressive dilation and systolic dysfunction of the right ventricle resulting in symptoms.
- Patients with acute worsening of PR should be evaluated for associated conditions such as pulmonary hypertension which increase the pressure gradient.
Prognosis
- Symptomatic patients are treated with pulmonary valve replacement and have a good prognosis.
Complications
- Progressive right ventricular dilation increases the risk of ventricular arrhythmias and sudden cardiac death. Patients with tetralogy of Fallot are at increased risk of developing these complications compared to patients with isolated PR.
Pathophysiology
- Patients with PR develop chronic right ventricular overload resulting in right ventricular remodelling and progressive decline in function.[9]
- Progressive dilation of the right ventricle results in functional tricuspid regurgitation and increases the risk of developing arrhythmias.
- The rate of decline in right ventricular systolic function is affected by associated conditions such as peripheral pulmonary artery stenosis and pulmonary hypertension which further increase the severity of pulmonary regurgitation.
- In patients with increased pulmonary artery pressure from dysfunction of LV or residual pulmonary artery stenosis increases the severity of PR.
- The severity of regurgitant jet is dependent on:[9]
- Size of the regurgitant orifice
- Afterload of the RV
- RV diastolic complaince
- Duration of RV diastole
According to 2014, ACC/AHA valvular heart disease guidelines the stages of severe pulmonary regurgitation are described as follows:[10]
Stage | Definition | Pulmonary Valve
Anatomy |
Valve Hemodynamics | Hemodynamic Consequences | Symptoms |
---|---|---|---|---|---|
C,D | Severe PR |
|
|
|
None or variable and dependent on cause of PR and RV function |
Causes
The most common causes of pulmonary regurgitation are following repair of tetralogy of Fallot and pulmonary stenosis. Other common causes include as follows:[11][12][13][14]
Congenital
Causes |
Acquired
Causes |
Chronic PR | Acute PR |
---|---|---|---|
|
|
|
|
Diagnosis
History and Symptoms
Clinical presentation of pulmonary regurgitation varies on the severity of the regurgitation and the right ventricular function.[8][15]
- Isolated pulmonary regurgitation is usually asymptomatic and is an incidental finding on 2D echo even when the regurgitation is severe.
- Patients with chronic PR develop right heart failure and present with the following symptoms:
- Intitial symptom of chronic PR is functional limitation of physical activity
- Ankle edema or swelling of the feet and legs
- Dyspnea on exertion
- Fatigue
- Hemoptysis or frothy sputum
- Nocturnal cough
- Palpitations or extra heart beats
- Patients with arrythmias present with palpitations, dizziness, or an episode of syncope.
Physical Examination
The physical examination findings in significant pulmonary regurgitation include:
Neck
- Increased JVP
- Prominent "a wave" may be present.
- Prominent "v wave" may be present in presence of tricuspid regurgitation.
- A palpable impulse (lift or heave) is usually present at the left lower sternal border because of right ventricular dilation.
Auscultation
- Pulmonic regurgitation is associated with wide splitting of S2.
- P2 is accentuated because of presence of pulmonary regurgitation. In case of, absence of pulmonic valves (congenital or secondary to surgical resection), P2 is inaudible.
- A right-sided S3 may be audible and may also be accentuated with inspiration.
- Likewise, a right-sided S4 may also be audible and accentuated with inspiration.
- Murmur of residual pulmonic regurgitation after Tetralogy of Fallot repair:[16]
- It is a low-pitched and soft murmur.
- Best heard along the second or third intercostal spaces adjacent to the left sternal border.
- It is accentuated by squatting and inspiration.
- It is made softer by Valsalva maneuvers or expiration.
- Murmur of pulmonic regurgitation associated with Pulmonic hypertension:[17]
- When the pulmonary artery systolic pressure exceeds 60 mm Hg, dilatation of the pulmonary artery ring may then result in Graham-Steell's murmur.
- It is a high-pitched, "blowing", early diastolic decrescendo murmur like that of aortic regurgitation.
- Best heard along the left parasternal region.
- It is accentuated by inspiration.
Echocardiography
It is the initial imaging diagnostic test to study the pulmonary valve, RVOT anatomy, to identify the presence and quantify the severity of PR. The findings include:[18]
- In adults, visualization of the pulmonary valve is obtained from the parasternal short-axis view at the level of the aortic valve or from a subcostal approach.[7][19]
- Pulmonary valve morphology anomalies such as bicuspid or quadricuspid valves, hypoplasia, dysplasia, absence of pulmonary valve and motion abnormalities can be detected.[20]
- PR is diagnosed my demonstrating a diastolic jet in the RV outflow tract towards the RV.
Colour Flow Doppler
The findings suggestive of significant PR include: [21][22][23][24][25]
- A narrow small central and spindle shaped regurgitant jet is seen in mild PR.
- In severe PR a wide diastolic jet at the origin which occupies 65% of the the RVOT width is seen on colour doppler imaging. The duration of the jet increases with increasing severity of PR.
- In severe PR, a rapid equalization of diastolic pressures between the pulmonary artery and RV occurs, resulting in a short-lived regurgitant jet which can mislead in diagnosis of the severity of PR.
- In patients with chronic significant PR, dilation of the RV can be demonstrated. In patients with physiologic PR and acute PR RV dimensions are normal.
Vena Contracta Width
It is a more accurate method to assess the severity of PR, but it lacks validation studies.[26]
Flow convergence method
It can be assessed in few patients but lacks validation studies.[27][28]
Pulsed Doppler
It is useful to assess the forward and regurgitant flows at the pulmonary annulus and the pulmonary artery, which can be used to calculate the regurgitant volume and regurgitant fraction.[29]
Spectral Doppler
The density of the CW signal provides a qualitative measure of regurgitation. [30]
- Pressure half-time (PHT) of less than 100 ms has a high sensitivity and specificity for identifying hemodynamically significant PR in congenital heart disease.[28]
- PR Index: It is a ratio expressed between the duration of PR and total diastole which is measured from the end of forward pulmonary flow to the beginning of the next forward pulmonary flow curve. It has shown to have equal sensitivity to determine the severity of PR when compared to CMR.[31]
- Myocardial performance index Tei index determined by tissue doppler imaging is a sensitive indicator of RV function in patients with chronic PR.[32]
Exercise Echocardiography
It is used to unmask latent RV dysfunction and is a helpful investigation to assess the RV function in patients who have underwent an intervention for significant PR.
Determination of severity of PR based on the findings on echocardiography:[33]
Parameters | Mild | Moderate | Severe |
---|---|---|---|
Pulmonic valve morphology | Normal | Normal or abnormal | Abnormal |
Colour flow PR jet width | Small, usually 10 mm in length with a narrow origin | Intermediate |
|
Continous wave signal of PR jet | Faint/slow deceleration | Dense/variable | Dense/steep deceleration, early termination of diastolic flow |
Pulmonic vs. Aortic flow by pulse wave | Normal or slightly increased | Intermediate | Greatly increased |
EKG
- EKG findings in chronic PR are non specific.
- In patients with tetralogy of Fallot increased QRS duration with widened QRS complex reflects the severity of PR and right ventricular dilation predisposing the patients to develop malignant arrythmias. [34][35]
- In patients with RV volume overload and isolated PR, QRS prolongation with rSr morphology can be seen in right precordial leads.
- RBB is common in majority of patients who have tetralogy of Fallot repair with right ventriculotomy.
Chest X-Ray
Chest X-Ray in chronic PR the following findings can be demonstrated:
- Cardiomegaly when there is dilation of the RV
- Pulmonary artery dilation
Cardiac MRI
Cardiac magnetic resonance(CMR) is a gold standard for assessment of morphology of the pulmonary valve, for quantification of the severity of the regurgitation and the RV systolic function.
- CMR is useful in quantification of the regurgitant volume and regurgitant fraction of PR by using sequences called “velocity- encoded phase-contrast images”.[36]
- CMR is useful for evaluating pulmonary regurgitant fraction, RV end-diastolic and end- systolic volumes, and RV ejection fraction
- CMR is the diagnostic modality preffered to determine the requirement of reintervention in patients with repaired tetralogy of Fallot and to assess the ventricular function and dimensions.
Cardiac Catheterization
Echo and CMR the investigations of choice in patients to detect and diagnose the severity of PR. Cardiac Catheterization is not a recommended for diagnosis of PR. In patients with poor echocardiographic windows and with pacemakers, CMR cannot be used, catheterization in such patients is a good alternative.
Treatment
Medical Therapy
- There are no specific medical measures for management of PR.
- Diuretics are recommended in patients with RV dysfunction for maintenance of fluid balance.
- In patients with repaired tetralogy of Fallot, ACE inhibitors or beta-blockers are used to reverse the neuroharmonal activation and improve the symptoms.[37][38]
Surgical Therapy
Indications for Surgery
Indications for Pulmonary Valve Replacement include:[39]
- Symptomatic patients with arrythmias or NYHA class higher than II
- Ejection Fraction of less than 40% when assessed with CMR
- Patients with progressive right ventricular regurgitation(right ventricular end- diastolic volume ≥160 mL/m2 or end-systolic volume ≥82 mL/m2 on CMR)
- Moderate to severe tricuspid valve regurgitation, resulting from annular dilation
- Patients at risk of developing arrythmias and with prolonged QRS duration.(total QRS duration ≥180 msec, or QRS duration increase >3.5 msec per year)
- Severe pulmonic regurgitation in a patient with another cardiac lesion that requires operative intervention
Timing Of Surgery
- Timing of pulmonary valve replacement is not well defined as in aortic and mitral regurgitation. However timely intervention is advised before the onset of RV dysfunction.[40]
- Delayed intervention has shown to have poor outcomes and higher rate of re-intervention.
- The prime goals of pulmonary valve replacement include improved functional class and quality of life, maintenance of right (and left) ventricular function, risk modification of arrhythmia and sudden cardiac death.[41]
Surgical Options
Pulmonary Valve Replacement(PVR) by surgical and percutaneous approach is the definitive treatment for the management of chronic PR and has proven to improve RV function, New York Heart Association Functional Class status, quality of life, and reduce risk for development of RV tachyarrhythmias and sudden cardiac death.[42]
Surgical Valve Implantation
- Various valved conduits are placed to replace the pulmonic valve which include Homografts from cadavers, valved conduits, and the Contegra bovine jugular vein graft or a bioprosthetic valve implanted directly in the RV outflow tract.[43]
- Bioprosthetic valves are usually preffered over mechanical valve prosthesis and have a longevity of around 15years.[44][45][46]
- Mechanical valves are preffered in patients who are at high risk of reoperation such as patients with RV dysfunction.
- Stenosis of the conduit is the major limitation and 25% of patients have to undergo a repeat intervention.
Transcatheter Pulmonary Valve Replacement
- The Melody transcatheter pulmonary valve(Medtronic) is approved by FDA in 2010.[47]
- The current transcatheter valves are designed to treat conduit and bioprosthetic valve failure only.[48][49][50][51][48]
- They are not useful to treat patients who had a RVOT reconstruction by transannular patching.
Complications
- Stent fracture:It leads to an increase in RV outflow tract gradient and RV pressure and its incidence is around 21% in 1 series that used the Melody valve and was the major reason for a repeat intervention.[52][53]
- Device instability and dislodgement[54]
- Coronary compression due to stent placement
- Pulmonary Artery obstruction
Outcomes
- Patients with percutaneous pulmonary valve replacement have good outcome and are free of reintervention at 1year.[55]
- Patients with CMR derived pre operative right ventricular end diastolic volume index of less than 160ml/m² and end systolic volume index of less than 80ml/m² showed better outcomes. [44][56][57]
Follow Up
- All the patients should undergo a baseline transthoracic echocardiogram after PVR.[8][58]
- Anticoagulation is recommended in patients with mechanical valves and aspirin for patients with bioprosthetic valves.[45]
- Oral anticoagulation in patients with bioprosthetic valves is recommended only when other indications such as atrial arrhythmia or prior thromoembolic event are present.
- All patients are adviced for a lifelong follow up to assess the valve morphology and RV systolic function.
Prevention
There are no primary preventive measures but all the patients with mechanical valve prosthesis are recommended for infective endocarditis prophylaxis.[59]
ACC / AHA Guidelines - Recommendations for Surgery for Adults With Previous Repair of Tetralogy of Fallot(DO NOT EDIT)
According to 2008 ACC/AHA guidelines, ACC/AHA 2008 Guidelines for the Management of Adults With Congenital Heart Disease[60]
Class I |
"1. Pulmonary valve replacement is indicated for severe pulmonary regurgitation and symptoms or decreased exercise tolerance.(Level of Evidence: B) " |
Class IIa |
"1. Pulmonary valve replacement is reasonable in adults with previous tetralogy of Fallot, severe pulmonary regurgitation, and any of the following:
|
Recommendations for Percutaneous Pulmonary Valve Replacement
According to 2011, Indications for Cardiac Catheterization and Intervention in Pediatric Cardiac Disease, A Scientific Statement From the American Heart Association.[61]
Class IIa |
"1.It is reasonable to consider percutaneous pulmonary valve replacement in a patient with an RV-to–pulmonary artery conduit with associated moderate to severe pulmonary regurgitation or stenosis provided the patient meets inclusion/exclusion criteria for the available valve .(Level of Evidence: A) " |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Paraskevas, G.; Koutsouflianiotis, K.; Iliou, K. (2017). "The first descriptions of various anatomical structures and embryological remnants of the heart: A systematic overview". International Journal of Cardiology. 227: 674–690. doi:10.1016/j.ijcard.2016.10.077. ISSN 0167-5273.
- ↑ 2.0 2.1 2.2 Choong CY, Abascal VM, Weyman J, Levine RA, Gentile F, Thomas JD; et al. (1989). "Prevalence of valvular regurgitation by Doppler echocardiography in patients with structurally normal hearts by two-dimensional echocardiography". Am Heart J. 117 (3): 636–42. PMID 2784023.
- ↑ Takao S, Miyatake K, Izumi S, Okamoto M, Kinoshita N, Nakagawa H; et al. (1988). "Clinical implications of pulmonary regurgitation in healthy individuals: detection by cross sectional pulsed Doppler echocardiography". Br Heart J. 59 (5): 542–50. PMC 1276894. PMID 3382565.
- ↑ 4.0 4.1 Klein AL, Burstow DJ, Tajik AJ, Zachariah PK, Taliercio CP, Taylor CL; et al. (1990). "Age-related prevalence of valvular regurgitation in normal subjects: a comprehensive color flow examination of 118 volunteers". J Am Soc Echocardiogr. 3 (1): 54–63. PMID 2310593.
- ↑ Chaturvedi RR, Redington AN (2007). "Pulmonary regurgitation in congenital heart disease". Heart. 93 (7): 880–9. doi:10.1136/hrt.2005.075234. PMC 1994453. PMID 17569817.
- ↑ Di Lullo L, Floccari F, Rivera R, Barbera V, Granata A, Otranto G; et al. (2013). "Pulmonary Hypertension and Right Heart Failure in Chronic Kidney Disease: New Challenge for 21st-Century Cardionephrologists". Cardiorenal Med. 3 (2): 96–103. doi:10.1159/000350952. PMC 3721135. PMID 23922549.
- ↑ 7.0 7.1 Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K; et al. (2010). "Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography". J Am Soc Echocardiogr. 23 (7): 685–713, quiz 786-8. doi:10.1016/j.echo.2010.05.010. PMID 20620859.
- ↑ 8.0 8.1 8.2 Warnes CA, Williams RG, Bashore TM, Child JS, Connolly HM, Dearani JA; et al. (2008). "ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults With Congenital Heart Disease). Developed in Collaboration With the American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons". J Am Coll Cardiol. 52 (23): e143–263. doi:10.1016/j.jacc.2008.10.001. PMID 19038677.
- ↑ 9.0 9.1 Bigdelian H, Mardani D, Sedighi M (2015). "The Effect of Pulmonary Valve Replacement (PVR) Surgery on Hemodynamics of Patients Who Underwent Repair of Tetralogy of Fallot (TOF)". J Cardiovasc Thorac Res. 7 (3): 122–5. doi:10.15171/jcvtr.2015.26. PMC 4586599. PMID 26430501.
- ↑ Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA; et al. (2014). "2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines". J Am Coll Cardiol. 63 (22): e57–185. doi:10.1016/j.jacc.2014.02.536. PMID 24603191.
- ↑ Bacha EA, Scheule AM, Zurakowski D, Erickson LC, Hung J, Lang P; et al. (2001). "Long-term results after early primary repair of tetralogy of Fallot". J Thorac Cardiovasc Surg. 122 (1): 154–61. doi:10.1067/mtc.2001.115156. PMID 11436049.
- ↑ Jonas SN, Kligerman SJ, Burke AP, Frazier AA, White CS (2016). "Pulmonary Valve Anatomy and Abnormalities: A Pictorial Essay of Radiography, Computed Tomography (CT), and Magnetic Resonance Imaging (MRI)". J Thorac Imaging. 31 (1): W4–12. doi:10.1097/RTI.0000000000000182. PMID 26656195.
- ↑ Ansari MM, Cardoso R, Garcia D, Sandhu S, Horlick E, Brinster D; et al. (2015). "Percutaneous Pulmonary Valve Implantation: Present Status and Evolving Future". J Am Coll Cardiol. 66 (20): 2246–55. doi:10.1016/j.jacc.2015.09.055. PMID 26564602.
- ↑ Warnes CA, Williams RG, Bashore TM, Child JS, Connolly HM, Dearani JA; et al. (2008). "ACC/AHA 2008 Guidelines for the Management of Adults with Congenital Heart Disease: Executive Summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to develop guidelines for the management of adults with congenital heart disease)". Circulation. 118 (23): 2395–451. doi:10.1161/CIRCULATIONAHA.108.190811. PMID 18997168.
- ↑ Shimazaki Y, Blackstone EH, Kirklin JW (1984). "The natural history of isolated congenital pulmonary valve incompetence: surgical implications". Thorac Cardiovasc Surg. 32 (4): 257–9. doi:10.1055/s-2007-1023399. PMID 6207619.
- ↑ Bousvaros, GeorgeA.; Deuchar, DennisC. (1961). "THE MURMUR OF PULMONARY REGURGITATION WHICH IS NOT ASSOCIATED WITH PULMONARY HYPERTENSION". The Lancet. 278 (7209): 962–964. doi:10.1016/S0140-6736(61)90798-X. ISSN 0140-6736.
- ↑ Würtemberger G, Dinkel E, Joos A, Matthys H (1989). "[Pulmonary hypertension. Clinical picture and therapy]". Radiologe. 29 (6): 263–6. PMID 2662241.
- ↑ Valente AM, Cook S, Festa P, Ko HH, Krishnamurthy R, Taylor AM; et al. (2014). "Multimodality imaging guidelines for patients with repaired tetralogy of fallot: a report from the AmericanSsociety of Echocardiography: developed in collaboration with the Society for Cardiovascular Magnetic Resonance and the Society for Pediatric Radiology". J Am Soc Echocardiogr. 27 (2): 111–41. doi:10.1016/j.echo.2013.11.009. PMID 24468055.
- ↑ Zoghbi WA, Enriquez-Sarano M, Foster E, Grayburn PA, Kraft CD, Levine RA; et al. (2003). "Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography". J Am Soc Echocardiogr. 16 (7): 777–802. doi:10.1016/S0894-7317(03)00335-3. PMID 12835667.
- ↑ Lancellotti P, Tribouilloy C, Hagendorff A, Popescu BA, Edvardsen T, Pierard LA; et al. (2013). "Recommendations for the echocardiographic assessment of native valvular regurgitation: an executive summary from the European Association of Cardiovascular Imaging". Eur Heart J Cardiovasc Imaging. 14 (7): 611–44. doi:10.1093/ehjci/jet105. PMID 23733442.
- ↑ Maciel BC, Simpson IA, Valdes-Cruz LM, Recusani F, Hoit B, Dalton N; et al. (1991). "Color flow Doppler mapping studies of "physiologic" pulmonary and tricuspid regurgitation: evidence for true regurgitation as opposed to a valve closing volume". J Am Soc Echocardiogr. 4 (6): 589–97. PMID 1760180.
- ↑ Maciel BC, Simpson IA, Valdes-Cruz LM, Recusani F, Hoit B, Dalton N; et al. (1991). "Color flow Doppler mapping studies of "physiologic" pulmonary and tricuspid regurgitation: evidence for true regurgitation as opposed to a valve closing volume". J Am Soc Echocardiogr. 4 (6): 589–97. PMID 1760180.
- ↑ Kobayashi J, Nakano S, Matsuda H, Arisawa J, Kawashima Y (1989). "Quantitative evaluation of pulmonary regurgitation after repair of tetralogy of Fallot using real-time flow imaging system". Jpn Circ J. 53 (7): 721–7. PMID 2810683.
- ↑ Williams RV, Minich LL, Shaddy RE, Pagotto LT, Tani LY (2002). "Comparison of Doppler echocardiography with angiography for determining the severity of pulmonary regurgitation". Am J Cardiol. 89 (12): 1438–41. PMID 12062746.
- ↑ Puchalski MD, Askovich B, Sower CT, Williams RV, Minich LL, Tani LY (2008). "Pulmonary regurgitation: determining severity by echocardiography and magnetic resonance imaging". Congenit Heart Dis. 3 (3): 168–75. doi:10.1111/j.1747-0803.2008.00184.x. PMID 18557879.
- ↑ Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K; et al. (2010). "Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography". J Am Soc Echocardiogr. 23 (7): 685–713, quiz 786-8. doi:10.1016/j.echo.2010.05.010. PMID 20620859.
- ↑ Lei MH, Chen JJ, Ko YL, Cheng JJ, Kuan P, Lien WP (1995). "Reappraisal of quantitative evaluation of pulmonary regurgitation and estimation of pulmonary artery pressure by continuous wave Doppler echocardiography". Cardiology. 86 (3): 249–56. PMID 7614499.
- ↑ 28.0 28.1 Silversides CK, Veldtman GR, Crossin J, Merchant N, Webb GD, McCrindle BW; et al. (2003). "Pressure half-time predicts hemodynamically significant pulmonary regurgitation in adult patients with repaired tetralogy of fallot". J Am Soc Echocardiogr. 16 (10): 1057–62. doi:10.1016/S0894-7317(03)00553-4. PMID 14566299.
- ↑ Goldberg SJ, Allen HD (1985). "Quantitative assessment by Doppler echocardiography of pulmonary or aortic regurgitation". Am J Cardiol. 56 (1): 131–5. PMID 4014018.
- ↑ Lei MH, Chen JJ, Ko YL, Cheng JJ, Kuan P, Lien WP (1995). "Reappraisal of quantitative evaluation of pulmonary regurgitation and estimation of pulmonary artery pressure by continuous wave Doppler echocardiography". Cardiology. 86 (3): 249–56. PMID 7614499.
- ↑ Li W, Davlouros PA, Kilner PJ, Pennell DJ, Gibson D, Henein MY; et al. (2004). "Doppler-echocardiographic assessment of pulmonary regurgitation in adults with repaired tetralogy of Fallot: comparison with cardiovascular magnetic resonance imaging". Am Heart J. 147 (1): 165–72. PMID 14691436.
- ↑ Yasuoka K, Harada K, Toyono M, Tamura M, Yamamoto F (2004). "Tei index determined by tissue Doppler imaging in patients with pulmonary regurgitation after repair of tetralogy of Fallot". Pediatr Cardiol. 25 (2): 131–6. doi:10.1007/s00246-003-0514-3. PMID 14648001.
- ↑ Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K; et al. (2010). "Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography". J Am Soc Echocardiogr. 23 (7): 685–713, quiz 786-8. doi:10.1016/j.echo.2010.05.010. PMID 20620859.
- ↑ Gatzoulis MA, Till JA, Somerville J, Redington AN (1995). "Mechanoelectrical interaction in tetralogy of Fallot. QRS prolongation relates to right ventricular size and predicts malignant ventricular arrhythmias and sudden death". Circulation. 92 (2): 231–7. PMID 7600655.
- ↑ Abd El Rahman MY, Abdul-Khaliq H, Vogel M, Alexi-Meskishvili V, Gutberlet M, Lange PE (2000). "Relation between right ventricular enlargement, QRS duration, and right ventricular function in patients with tetralogy of Fallot and pulmonary regurgitation after surgical repair". Heart. 84 (4): 416–20. PMC 1729453. PMID 10995413.
- ↑ Wald RM, Redington AN, Pereira A, Provost YL, Paul NS, Oechslin EN; et al. (2009). "Refining the assessment of pulmonary regurgitation in adults after tetralogy of Fallot repair: should we be measuring regurgitant fraction or regurgitant volume?". Eur Heart J. 30 (3): 356–61. doi:10.1093/eurheartj/ehn595. PMID 19164336.
- ↑ Bolger AP, Sharma R, Li W, Leenarts M, Kalra PR, Kemp M; et al. (2002). "Neurohormonal activation and the chronic heart failure syndrome in adults with congenital heart disease". Circulation. 106 (1): 92–9. PMID 12093776.
- ↑ Davos CH, Davlouros PA, Wensel R, Francis D, Davies LC, Kilner PJ; et al. (2002). "Global impairment of cardiac autonomic nervous activity late after repair of tetralogy of Fallot". Circulation. 106 (12 Suppl 1): I69–75. PMID 12354712.
- ↑ Geva T (2006). "Indications and timing of pulmonary valve replacement after tetralogy of Fallot repair". Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu: 11–22. doi:10.1053/j.pcsu.2006.02.009. PMID 16638542.
- ↑ Therrien J, Provost Y, Merchant N, Williams W, Colman J, Webb G (2005). "Optimal timing for pulmonary valve replacement in adults after tetralogy of Fallot repair". Am J Cardiol. 95 (6): 779–82. doi:10.1016/j.amjcard.2004.11.037. PMID 15757612.
- ↑ Discigil B, Dearani JA, Puga FJ, Schaff HV, Hagler DJ, Warnes CA; et al. (2001). "Late pulmonary valve replacement after repair of tetralogy of Fallot". J Thorac Cardiovasc Surg. 121 (2): 344–51. doi:10.1067/mtc.2001.111209. PMID 11174741.
- ↑ Geva T, Gauvreau K, Powell AJ, Cecchin F, Rhodes J, Geva J; et al. (2010). "Randomized trial of pulmonary valve replacement with and without right ventricular remodeling surgery". Circulation. 122 (11 Suppl): S201–8. doi:10.1161/CIRCULATIONAHA.110.951178. PMC 2943672. PMID 20837914.
- ↑ Tweddell JS, Pelech AN, Frommelt PC, Mussatto KA, Wyman JD, Fedderly RT; et al. (2000). "Factors affecting longevity of homograft valves used in right ventricular outflow tract reconstruction for congenital heart disease". Circulation. 102 (19 Suppl 3): III130–5. PMID 11082375.
- ↑ 44.0 44.1 Lee C, Kim YM, Lee CH, Kwak JG, Park CS, Song JY; et al. (2012). "Outcomes of pulmonary valve replacement in 170 patients with chronic pulmonary regurgitation after relief of right ventricular outflow tract obstruction: implications for optimal timing of pulmonary valve replacement". J Am Coll Cardiol. 60 (11): 1005–14. doi:10.1016/j.jacc.2012.03.077. PMID 22921969.
- ↑ 45.0 45.1 Jang W, Kim YJ, Choi K, Lim HG, Kim WH, Lee JR (2012). "Mid-term results of bioprosthetic pulmonary valve replacement in pulmonary regurgitation after tetralogy of Fallot repair". Eur J Cardiothorac Surg. 42 (1): e1–8. doi:10.1093/ejcts/ezs219. PMID 22561653.
- ↑ Burchill LJ, Wald RM, Harris L, Colman JM, Silversides CK (2011). "Pulmonary valve replacement in adults with repaired tetralogy of Fallot". Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 14 (1): 92–7. doi:10.1053/j.pcsu.2011.01.016. PMID 21444054.
- ↑ McElhinney DB, Hellenbrand WE, Zahn EM, Jones TK, Cheatham JP, Lock JE; et al. (2010). "Short- and medium-term outcomes after transcatheter pulmonary valve placement in the expanded multicenter US melody valve trial". Circulation. 122 (5): 507–16. doi:10.1161/CIRCULATIONAHA.109.921692. PMC 4240270. PMID 20644013.
- ↑ 48.0 48.1 Zahn EM, Hellenbrand WE, Lock JE, McElhinney DB (2009). "Implantation of the melody transcatheter pulmonary valve in patients with a dysfunctional right ventricular outflow tract conduit early results from the u.s. Clinical trial". J Am Coll Cardiol. 54 (18): 1722–9. doi:10.1016/j.jacc.2009.06.034. PMID 19850214.
- ↑ Khambadkone S, Coats L, Taylor A, Boudjemline Y, Derrick G, Tsang V; et al. (2005). "Percutaneous pulmonary valve implantation in humans: results in 59 consecutive patients". Circulation. 112 (8): 1189–97. doi:10.1161/CIRCULATIONAHA.104.523266. PMID 16103239.
- ↑ Romeih S, Kroft LJ, Bokenkamp R, Schalij MJ, Grotenhuis H, Hazekamp MG; et al. (2009). "Delayed improvement of right ventricular diastolic function and regression of right ventricular mass after percutaneous pulmonary valve implantation in patients with congenital heart disease". Am Heart J. 158 (1): 40–6. doi:10.1016/j.ahj.2009.04.023. PMID 19540390.
- ↑ Vezmar M, Chaturvedi R, Lee KJ, Almeida C, Manlhiot C, McCrindle BW; et al. (2010). "Percutaneous pulmonary valve implantation in the young 2-year follow-up". JACC Cardiovasc Interv. 3 (4): 439–48. doi:10.1016/j.jcin.2010.02.003. PMID 20398873.
- ↑ Nordmeyer J, Khambadkone S, Coats L, Schievano S, Lurz P, Parenzan G; et al. (2007). "Risk stratification, systematic classification, and anticipatory management strategies for stent fracture after percutaneous pulmonary valve implantation". Circulation. 115 (11): 1392–7. doi:10.1161/CIRCULATIONAHA.106.674259. PMID 17339542.
- ↑ Lurz P, Coats L, Khambadkone S, Nordmeyer J, Boudjemline Y, Schievano S; et al. (2008). "Percutaneous pulmonary valve implantation: impact of evolving technology and learning curve on clinical outcome". Circulation. 117 (15): 1964–72. doi:10.1161/CIRCULATIONAHA.107.735779. PMID 18391109.
- ↑ Kostolny M, Tsang V, Nordmeyer J, Van Doorn C, Frigiola A, Khambadkone S; et al. (2008). "Rescue surgery following percutaneous pulmonary valve implantation". Eur J Cardiothorac Surg. 33 (4): 607–12. doi:10.1016/j.ejcts.2007.12.034. PMID 18255307.
- ↑ Boudjemline Y, Brugada G, Van-Aerschot I, Patel M, Basquin A, Bonnet C; et al. (2012). "Outcomes and safety of transcatheter pulmonary valve replacement in patients with large patched right ventricular outflow tracts". Arch Cardiovasc Dis. 105 (8–9): 404–13. doi:10.1016/j.acvd.2012.05.002. PMID 22958883.
- ↑ Oosterhof T, van Straten A, Vliegen HW, Meijboom FJ, van Dijk AP, Spijkerboer AM; et al. (2007). "Preoperative thresholds for pulmonary valve replacement in patients with corrected tetralogy of Fallot using cardiovascular magnetic resonance". Circulation. 116 (5): 545–51. doi:10.1161/CIRCULATIONAHA.106.659664. PMID 17620511.
- ↑ Geva T, Sandweiss BM, Gauvreau K, Lock JE, Powell AJ (2004). "Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging". J Am Coll Cardiol. 43 (6): 1068–74. doi:10.1016/j.jacc.2003.10.045. PMID 15028368.
- ↑ Baumgartner H, Bonhoeffer P, De Groot NM, de Haan F, Deanfield JE, Galie N; et al. (2010). "ESC Guidelines for the management of grown-up congenital heart disease (new version 2010)". Eur Heart J. 31 (23): 2915–57. doi:10.1093/eurheartj/ehq249. PMID 20801927.
- ↑ Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA; et al. (2014). "2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines". Circulation. 129 (23): 2440–92. doi:10.1161/CIR.0000000000000029. PMID 24589852.
- ↑ Warnes CA, Williams RG, Bashore TM, Child JS, Connolly HM, Dearani JA; et al. (2008). "ACC/AHA 2008 Guidelines for the Management of Adults with Congenital Heart Disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to develop guidelines on the management of adults with congenital heart disease)". Circulation. 118 (23): e714–833. doi:10.1161/CIRCULATIONAHA.108.190690. PMID 18997169.
- ↑ Feltes TF, Bacha E, Beekman RH, Cheatham JP, Feinstein JA, Gomes AS; et al. (2011). "Indications for cardiac catheterization and intervention in pediatric cardiac disease: a scientific statement from the American Heart Association". Circulation. 123 (22): 2607–52. doi:10.1161/CIR.0b013e31821b1f10. PMID 21536996.