Aortic regurgitation

Last updated
Aortic regurgitation
Other namesAortic insufficiency
Blausen 0039 AorticRegurgitation.png
Illustration of aortic regurgitation
Specialty Cardiology   OOjs UI icon edit-ltr-progressive.svg
Symptoms Dyspnea on exertion, Orthopnea [1]
CausesAortic root dilation [1]
Diagnostic method Transthoracic echocardiography [2]
TreatmentVasodilators(depends on the individuals condition, maybe surgery Aortic valve replacement) [1] [3]

Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a consequence, the cardiac muscle is forced to work harder than normal. [4]

Contents

Signs and symptoms

Symptoms of aortic regurgitation are similar to those of heart failure and include the following: [1]

Causes

In terms of the cause of aortic regurgitation, is often due to the aortic root dilation ( annuloaortic ectasia ), which is idiopathic in over 80% of cases, but otherwise may result from aging, syphilitic aortitis, osteogenesis imperfecta, aortic dissection, Behçet's disease, reactive arthritis and systemic hypertension. [1] Aortic root dilation is the most common cause of aortic regurgitation in developed countries. [5] Additionally, aortic regurgitation has been linked to the use of some medications, specifically medications containing fenfluramine or dexfenfluramine isomers and dopamine agonists. [6] [7] Other potential causes that affect the valve directly include Marfan syndrome, Ehlers–Danlos syndrome, ankylosing spondylitis, and systemic lupus erythematosus. In acute cases of aortic regurgitation, the main causes are infective endocarditis, aortic dissection or trauma. [1]

Pathophysiology

Micrograph of myxomatous degeneration - a cause of aortic regurgitation. Myxomatous aortic valve.jpg
Micrograph of myxomatous degeneration – a cause of aortic regurgitation.

The mechanism of aortic regurgitation, comprises the pressure in the left ventricle falling below the pressure in the aorta, the aortic valve is not able to completely close. This causes a leaking of blood from the aorta into the left ventricle. This means that some of the blood that was already ejected from the heart is regurgitating back into the heart. The percentage of blood that regurgitates back through the aortic valve due to AR is known as the regurgitant fraction. This regurgitant flow causes a decrease in the diastolic blood pressure in the aorta, and therefore an increase in the pulse pressure. Since some of the blood that is ejected during systole regurgitates back into the left ventricle during diastole, there is decreased effective forward flow in AR. [8] [9]

While diastolic blood pressure is diminished and the pulse pressure widens, systolic blood pressure generally remains normal or can even be slightly elevated, this is because sympathetic nervous system and the renin-angiotensin-aldosterone axis of the kidneys compensate for the decreased cardiac output. [10] Catecholamines will increase the heart rate and increase the strength of ventricular contraction, directly increasing cardiac output. Catecholamines will also cause peripheral vasoconstriction, which causes increased systemic vascular resistance and ensures that organs are adequately perfused. [11] Renin, a proteolytic enzyme, cleaves angiotensinogen to angiotensin I, which is converted to angiotensin II. [12] In the case of chronic aortic with resultant cardiac remodeling, heart failure will develop, and it is possible to see systolic pressures diminish. [13] Aortic regurgitation causes both volume overload (elevated preload) and pressure overload (elevated afterload) of the heart. [14]

The volume overload, due to elevated pulse pressure and the systemic effects of neuroendocrine hormones causes left ventricular hypertrophy (LVH). [9] There is both concentric hypertrophy and eccentric hypertrophy in AI. The concentric hypertrophy is due to the increased left ventricular pressure overload associated with AI, while the eccentric hypertrophy is due to volume overload caused by the regurgitant fraction. [15]

Physiologically, in individuals with a normally functioning aortic valve, the valve is only open when the pressure in the left ventricle is higher than the pressure in the aorta. This allows the blood to be ejected from the left ventricle into the aorta during ventricular systole. The amount of blood that is ejected by the heart is known as the stroke volume . Under normal conditions, >50% of the blood in a filled left ventricle is ejected into the aorta to be used by the body. After ventricular systole, the pressure in the left ventricle decreases as it relaxes and begins to fill up with blood from the left atrium. This relaxation of the left ventricle (early ventricular diastole) causes a fall in its pressure. When the pressure in the left ventricle falls below the pressure in the aorta, the aortic valve will close, preventing blood in the aorta from going back into the left ventricle. [16] [17] [18]

Diagnosis

Ultrasound showing aortic regurgitation and vegetations on the aortic valve. [19]

In terms of the diagnosis of aortic regurgitation a common test for the evaluation of the severity is transthoracic echocardiography, which can provide two-dimensional views of the regurgitant jet, allow measurement of velocity, and estimate jet volume. [2] The findings in severe aortic regurgitation, based on the 2012 American College of Cardiology/American Heart Association guidelines include: [20] [21]

Chest X-ray can assist in making the diagnosis, showing left ventricular hypertrophy and dilated aorta. ECG typically indicates left ventricular hypertrophy. Cardiac chamber catheterization assists in assessing the severity of regurgitation and any left ventricular dysfunction. [1]

Physical examination

The physical examination of an individual with aortic regurgitation involves auscultation of the heart to listen for the murmur of aortic regurgitation and the S3 heart sound (S3 gallop correlates with development of LV dysfunction). [1] The murmur of chronic aortic regurgitation is typically described as early diastolic and decrescendo, which is best heard in the third left intercostal space and may radiate along the left sternal border. [22]

If there is increased stroke volume of the left ventricle due to volume overload, an ejection systolic 'flow' murmur may also be present when auscultating the same aortic area. Unless there is concomitant aortic valve stenosis, the murmur should not start with an ejection click. There may also be an Austin Flint murmur, [1] a soft mid-diastolic rumble heard at the apical area; it appears when a regurgitant jet of blood from severe aortic regurgitation partially closes the anterior mitral leaflet. Peripheral physical signs of aortic regurgitation are related to the high pulse pressure and the rapid decrease in blood pressure during diastole due to blood returning to the heart from the aorta through the incompetent aortic valve, although the usefulness of some of the eponymous signs has been questioned: [23] Phonocardiograms detect AI by having electric voltage mimic the sounds the heart makes. [24]

Characteristics- indicative of aortic regurgitation are as follow:

Classification

The hemodynamic sequelae of AI are dependent on the rate of onset of AI. [28] Therefore, can be acute or chronic as follows:

Aortic regurgitation
Acute AR usually presents as florid congestive heart failure, and will not have any of the signs associated with chronic AR since the left ventricle had not yet developed the eccentric hypertrophy and dilatation that allow an increased stroke volume, which in turn cause bounding peripheral pulses. On auscultation, there may be a short diastolic murmur and a soft S1. S1 is soft because the elevated filling pressures close the mitral valve in diastole.[ medical citation needed ]

Treatment

Aortic regurgitation can be treated either medically or surgically, depending on the acuteness of presentation, the symptoms and signs associated with the disease process, and the degree of left ventricular dysfunction. [5] [31] Surgical treatment in asymptomatic patients has been recommended if the ejection fraction falls to 50% or below, in the face of progressive and severe left ventricular dilatation, or with symptoms or abnormal response to exercise testing. For both groups of patients, surgery before the development of worsening ejection fraction/LV dilatation is expected to reduce the risk of sudden death, and is associated with lower peri-operative mortality. Also, surgery is optimally performed immediately in acute cases. [1] [5]

Medical treatment

Losartan is a type of angiotensin II receptor antagonist. Losartan structure.svg
Losartan is a type of angiotensin II receptor antagonist.

Medical therapy of chronic aortic regurgitation that is stable and asymptomatic involves the use of vasodilators. [1] Trials have shown a short-term benefit in the use of ACE inhibitors or angiotensin II receptor antagonists, nifedipine, and hydralazine in improving left ventricular wall stress, ejection fraction, and mass. [5] The goal in using these pharmacologic agents is to decrease the afterload so that the left ventricle is somewhat spared. [32] The regurgitant fraction may not change significantly, since the gradient between the aortic and left ventricular pressures is usually fairly low at the initiation of treatment. Other rather conservative medical treatments for stable and asymptomatic cases include low sodium diet, diuretics, digoxin, calcium blockers and avoiding very strenuous activity. [1]

As of 2007, the American Heart Association no longer recommends antibiotics for endocarditis prophylaxis before certain procedures in patients with aortic regurgitation. [33] Antibiotic prophylaxis to prevent endocarditis before gastrointestinal or genitourinary procedures is no longer recommended for any patient with valvular disease. [33] Cardiac stress test is useful in identifying individuals that may be best suited for surgical intervention. [34] Radionuclide angiography is recommended and useful when the systolic wall stress is calculated and combined to the results. [35]

Surgery

A surgical treatment for AR is aortic valve replacement; [3] this is currently an open-heart procedure. In the case of severe acute aortic regurgitation, all individuals should undergo surgery, if there are no absolute contraindications (for surgery). [5] [36] Individuals with bacteremia with aortic valve endocarditis should not wait for treatment with antibiotics to take effect, given the high mortality associated with the acute AI. Replacement with an aortic valve homograft should be performed if feasible. [37] [38]

Indications for surgery for chronic severe aortic regurgitation [20]
SymptomsEjection fractionAdditional Findings
Present
(NYHA II-IV)		Anynone
Absent> 50%Abnormal exercise test, severe LV dilatation
(systolic ventricular diameter >55 mm)
Absent<=50 %none
Cardiac surgery for other cause (i.e.: CAD, other valvular disease, ascending aortic aneurysm)

Prognosis

The risk of death in individuals with aortic regurgitation, dilated ventricle, normal ejection fraction who are asymptomatic is about 0.2 percent per year. Risk increases if the ejection fraction decreases or if the individual develops symptoms. [36]

Individuals with chronic (severe) aortic regurgitation follow a course that once symptoms appear, surgical intervention is needed. AI is fatal in 10 to 20% of individuals who do not undergo surgery for this condition. Left ventricle dysfunction determines to an extent the outlook for severity of aortic regurgitation cases. [5] [39]

Related Research Articles

<span class="mw-page-title-main">Aortic stenosis</span> Narrowing of the exit of the hearts left ventricle

Aortic stenosis is the narrowing of the exit of the left ventricle of the heart, such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If heart failure, loss of consciousness, or heart related chest pain occur due to AS the outcomes are worse. Loss of consciousness typically occurs with standing or exercising. Signs of heart failure include shortness of breath especially when lying down, at night, or with exercise, and swelling of the legs. Thickening of the valve without narrowing is known as aortic sclerosis.

<span class="mw-page-title-main">Heart valve</span> A flap of tissue that prevent backflow of blood around the heart

A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. Four valves are usually present in a mammalian heart and together they determine the pathway of blood flow through the heart. A heart valve opens or closes according to differential blood pressure on each side.

<span class="mw-page-title-main">Heart sounds</span> Noise generated by the beating heart

Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart.

<span class="mw-page-title-main">Aortic valve</span> Valve in the human heart between the left ventricle and the aorta

The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. The aortic valve normally has three cusps or leaflets, although in 1–2% of the population it is found to congenitally have two leaflets. The aortic valve is the last structure in the heart the blood travels through before stopping the flow through the systemic circulation.

<span class="mw-page-title-main">Heart murmur</span> Medical condition

Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel. This occurs when turbulent blood flow creates a sound loud enough to hear with a stethoscope. Turbulent blood flow is not smooth. The sound differs from normal heart sounds by their characteristics. For example, heart murmurs may have a distinct pitch, duration and timing. The major way health care providers examine the heart on physical exam is heart auscultation; another clinical technique is palpation, which can detect by touch when such turbulence causes the vibrations called cardiac thrill. A murmur is a sign found during the cardiac exam. Murmurs are of various types and are important in the detection of cardiac and valvular pathologies.

<span class="mw-page-title-main">Ventricle (heart)</span> Chamber of the heart

A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles, while intraventricular means within one ventricle.

<span class="mw-page-title-main">Pulse pressure</span> Difference between systolic and diastolic blood pressure

Pulse pressure is the difference between systolic and diastolic blood pressure. It is measured in millimeters of mercury (mmHg). It represents the force that the heart generates each time it contracts. Healthy pulse pressure is around 40 mmHg. A pulse pressure that is consistently 60 mmHg or greater is likely to be associated with disease, and a pulse pressure of 50 mmHg or more increases the risk of cardiovascular disease. Pulse pressure is considered low if it is less than 25% of the systolic. A very low pulse pressure can be a symptom of disorders such as congestive heart failure.

<span class="mw-page-title-main">Afterload</span> Pressure in the wall of the left ventricle during ejection

Afterload is the pressure that the heart must work against to eject blood during systole. Afterload is proportional to the average arterial pressure. As aortic and pulmonary pressures increase, the afterload increases on the left and right ventricles respectively. Afterload changes to adapt to the continually changing demands on an animal's cardiovascular system. Afterload is proportional to mean systolic blood pressure and is measured in millimeters of mercury.

<span class="mw-page-title-main">Diastole</span> Part of the cardiac cycle

Diastole is the relaxed phase of the cardiac cycle when the chambers of the heart are re-filling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricular diastole the relaxing of the ventricles.

<span class="mw-page-title-main">Mitral stenosis</span> Heart disease with narrowing of valve

Mitral stenosis is a valvular heart disease characterized by the narrowing of the opening of the mitral valve of the heart. It is almost always caused by rheumatic valvular heart disease. Normally, the mitral valve is about 5 cm2 during diastole. Any decrease in area below 2 cm2 causes mitral stenosis. Early diagnosis of mitral stenosis in pregnancy is very important as the heart cannot tolerate increased cardiac output demand as in the case of exercise and pregnancy. Atrial fibrillation is a common complication of resulting left atrial enlargement, which can lead to systemic thromboembolic complications such as stroke.

<span class="mw-page-title-main">Bicuspid aortic valve</span> Medical condition

Bicuspid aortic valve (BAV) is a form of heart disease in which two of the leaflets of the aortic valve fuse during development in the womb resulting in a two-leaflet (bicuspid) valve instead of the normal three-leaflet (tricuspid) valve. BAV is the most common cause of heart disease present at birth and affects approximately 1.3% of adults. Normally, the mitral valve is the only bicuspid valve and this is situated between the heart's left atrium and left ventricle. Heart valves play a crucial role in ensuring the unidirectional flow of blood from the atrium to the ventricles, or from the ventricle to the aorta or pulmonary trunk. BAV is normally inherited.

<span class="mw-page-title-main">Mitral regurgitation</span> Form of valvular heart disease

Mitral regurgitation(MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. It is the abnormal leaking of blood backwards – regurgitation from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts. Mitral regurgitation is the most common form of valvular heart disease.

Aortic valve replacement is a procedure whereby the failing aortic valve of a patient's heart is replaced with an artificial heart valve. The aortic valve may need to be replaced because:

A transthoracic echocardiogram (TTE) is the most common type of echocardiogram, which is a still or moving image of the internal parts of the heart using ultrasound. In this case, the probe is placed on the chest or abdomen of the subject to get various views of the heart. It is used as a non-invasive assessment of the overall health of the heart, including a patient's heart valves and degree of heart muscle contraction. The images are displayed on a monitor for real-time viewing and then recorded.

<span class="mw-page-title-main">Valvular heart disease</span> Disease in the valves of the heart

Valvular heart disease is any cardiovascular disease process involving one or more of the four valves of the heart. These conditions occur largely as a consequence of aging, but may also be the result of congenital (inborn) abnormalities or specific disease or physiologic processes including rheumatic heart disease and pregnancy.

Regurgitation is blood flow in the opposite direction from normal, as the backward flowing of blood into the heart or between heart chambers. It is the circulatory equivalent of backflow in engineered systems. It is sometimes called reflux.

<span class="mw-page-title-main">Tricuspid regurgitation</span> Type of valvular heart disease

Tricuspid regurgitation (TR), also called tricuspid insufficiency, is a type of valvular heart disease in which the tricuspid valve of the heart, located between the right atrium and right ventricle, does not close completely when the right ventricle contracts (systole). TR allows the blood to flow backwards from the right ventricle to the right atrium, which increases the volume and pressure of the blood both in the right atrium and the right ventricle, which may increase central venous volume and pressure if the backward flow is sufficiently severe.

The following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in cardiology are called cardiologists.

A plot of a system's pressure versus volume has long been used to measure the work done by the system and its efficiency. This analysis can be applied to heat engines and pumps, including the heart. A considerable amount of information on cardiac performance can be determined from the pressure vs. volume plot. A number of methods have been determined for measuring PV-loop values experimentally.

<span class="mw-page-title-main">Heart failure with preserved ejection fraction</span> Medical condition

Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure in which the ejection fraction – the percentage of the volume of blood ejected from the left ventricle with each heartbeat divided by the volume of blood when the left ventricle is maximally filled – is normal, defined as greater than 50%; this may be measured by echocardiography or cardiac catheterization. Approximately half of people with heart failure have preserved ejection fraction, while the other half have a reduction in ejection fraction, called heart failure with reduced ejection fraction (HFrEF).

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 Chapter 1: Diseases of the Cardiovascular system > Section: Valvular Heart Disease in: Elizabeth D Agabegi; Agabegi, Steven S. (2008). Step-Up to Medicine (Step-Up Series) . Hagerstwon, MD: Lippincott Williams & Wilkins. ISBN   978-0-7817-7153-5.
  2. 1 2 Lancellotti, P.; Tribouilloy, C.; Hagendorff, A.; Moura, L.; Popescu, B. A.; Agricola, E.; Monin, J. L.; Pierard, L. A.; Badano, L.; Zamorano, J. L.; Sicari, R.; Vahanian, A.; Roelandt, J. R. T. C. (7 April 2010). "European Association of Echocardiography recommendations for the assessment of valvular regurgitation. Part 1: aortic and pulmonary regurgitation (native valve disease)" (PDF). European Journal of Echocardiography. 11 (3): 223–244. doi: 10.1093/ejechocard/jeq030 . PMID   20375260 . Retrieved 4 June 2016.
  3. 1 2 Choices, NHS. "Aortic valve replacement - Why it's done - NHS Choices". www.nhs.uk. Retrieved 4 June 2016.
  4. ↑ "Aortic insufficiency: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-05-16.
  5. 1 2 3 4 5 6 "Aortic Regurgitation: Background, Pathophysiology, Etiology". 2018-11-19.{{cite journal}}: Cite journal requires |journal= (help)
  6. ↑ Schade R, Andersohn F, Suissa S, Haverkamp W, Garbe E (2007). "Dopamine agonists and the risk of cardiac-valve regurgitation". N. Engl. J. Med. 356 (1): 29–38. doi: 10.1056/NEJMoa062222 . PMID   17202453.
  7. ↑ Zanettini R, Antonini A, Gatto G, Gentile R, Tesei S, Pezzoli G (2007). "Valvular heart disease and the use of dopamine agonists for Parkinson's disease". N. Engl. J. Med. 356 (1): 39–46. doi: 10.1056/NEJMoa054830 . PMID   17202454.
  8. ↑ Hijazi, Ziyad M.; Ruiz, Carlos E.; Bonhoeffer, Philipp; Feldman, Ted (2006-01-17). Transcatheter Valve Repair. CRC Press. p. 31. ISBN   9781841844725.
  9. 1 2 3 Maurer, Gerald (2006-07-01). "Aortic regurgitation". Heart. 92 (7): 994–1000. doi:10.1136/hrt.2004.042614. ISSN   1355-6037. PMC   1860728 . PMID   16775114.
  10. ↑ Galbraith, Alan; Bullock, Shane; Manias, Elizabeth; Hunt, Barry; Richards, Ann (2015-08-12). Fundamentals of Pharmacology: An Applied Approach for Nursing and Health. Routledge. p. 483. ISBN   9781317325871.
  11. ↑ Ginsburg, Geoffrey S.; Willard, Huntington F. (2013-01-01). Genomic and Personalized Medicine. Academic Press. p. 543. ISBN   9780123822277.
  12. ↑ Kumar, Vinay; Abbas, Abul K.; Aster, Jon C. (2012-05-01). Robbins Basic Pathology. Elsevier Health Sciences. p. 331. ISBN   978-1455737871.
  13. ↑ Topol, Eric J.; Califf, Robert M. (2007). Textbook of Cardiovascular Medicine. Lippincott Williams & Wilkins. p. 381. ISBN   9780781770125 . Retrieved 4 June 2016.
  14. ↑ Haase, Jürgen; Schäfers, Hans-Joachim; Sievert, Horst; Waksman, Ron (2010-04-01). Cardiovascular Interventions in Clinical Practice. John Wiley & Sons. p. 104. ISBN   9781444316711.
  15. ↑ Haase, Jürgen; Schäfers, Hans-Joachim; Sievert, Horst; Waksman, Ron (2010-04-01). Cardiovascular Interventions in Clinical Practice. John Wiley & Sons. p. 102. ISBN   9781444316711 . Retrieved 4 June 2016.
  16. ↑ "Aortic Valve Anatomy: Overview, Gross Anatomy, Microscopic Anatomy". 2018-09-25.{{cite journal}}: Cite journal requires |journal= (help)
  17. ↑ Mulroney, Susan; Myers, Adam (2015-08-31). Netter's Essential Physiology. Elsevier Health Sciences. p. 118. ISBN   9780323375849.
  18. ↑ Mandeville, Lisa K.; Troiano, Nan H. (1999-01-01). High Risk and Critical Care Intrapartum Nursing. Lippincott Williams & Wilkins. p. 67. ISBN   9780397554676.
  19. ↑ "UOTW#69 - Ultrasound of the Week". Ultrasound of the Week. 3 April 2016. Retrieved 27 May 2017.
  20. 1 2 Bonow, RO; American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease); Society of Cardiovascular Anesthesiologists; Bonow, RO; Carabello, BA; Chatterjee, K; De Leon Jr, AC; Faxon, DP; et al. (2006). "ACC/AHA guidelines 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. 48 (3): e1–148. doi: 10.1016/j.jacc.2006.05.021 . PMID   16875962.
  21. ↑ Nishimura, Rick A.; Otto, Catherine M.; Bonow, Robert O.; Carabello, Blase A.; Erwin, John P.; Guyton, Robert A.; O'Gara, Patrick T.; Ruiz, Carlos E.; Skubas, Nikolaos J. (2014-07-01). "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". The Journal of Thoracic and Cardiovascular Surgery. 148 (1): e1–e132. doi: 10.1016/j.jtcvs.2014.05.014 . ISSN   1097-685X. PMID   24939033.
  22. ↑ Bickley, Lynn S.; Szilagyi, Peter G.; Bates, Barbara (2009-01-01). Bates' Guide to Physical Examination and History Taking. Lippincott Williams & Wilkins. p. 368. ISBN   9780781780582.
  23. ↑ Babu AN, Kymes SM, Carpenter Fryer SM (2003). "Eponyms and the diagnosis of aortic regurgitation: what says the evidence?". Ann. Intern. Med. 138 (9): 736–42. doi:10.7326/0003-4819-138-9-200305060-00010. PMID   12729428. S2CID   19014006.
  24. ↑ Tang, Hong; Zhang, Jinhui; Sun, Jian; Qiu, Tianshuang; Park, Yongwan (1 April 2016). "Phonocardiogram signal compression using sound repetition and vector quantization". Computers in Biology and Medicine. 71: 24–34. doi: 10.1016/j.compbiomed.2016.01.017 . ISSN   0010-4825. PMID   26871603.
  25. ↑ Murthy, Pothuri Radha Krishna (2013-07-30). Heart in Fours: Cardiology for Residents and Practitioners. JP Medical Ltd. p. 47. ISBN   9789350904930 . Retrieved 4 June 2016.
  26. 1 2 3 4 Camm, Christian F.; Camm, A. John (2016-01-06). Clinical Guide to Cardiology. John Wiley & Sons. p. 10. ISBN   9781119079255 . Retrieved 4 June 2016.
  27. 1 2 3 4 5 6 7 8 9 Ashrafian, Hutan (8 March 2006). "Pulsatile pseudo-proptosis, aortic regurgitation and 31 eponyms". International Journal of Cardiology. 107 (3): 421–423. doi:10.1016/j.ijcard.2005.01.060. ISSN   0167-5273. PMID   16503268. – via ScienceDirect  (Subscription may be required or content may be available in libraries.)
  28. ↑ Mokadam, Nahush A.; Stout, Karen K.; Verrier, Edward D. (2011-01-01). "Management of Acute Regurgitation in Left-Sided Cardiac Valves". Texas Heart Institute Journal. 38 (1): 9–19. ISSN   0730-2347. PMC   3060740 . PMID   21423463.
  29. ↑ Stout, Karen K.; Verrier, Edward D. (2009-06-30). "Acute Valvular Regurgitation". Circulation. 119 (25): 3232–3241. doi: 10.1161/CIRCULATIONAHA.108.782292 . ISSN   0009-7322. PMID   19564568.
  30. ↑ Bekeredjian, Raffi; Grayburn, Paul A. (2005-07-05). "Valvular Heart Disease Aortic Regurgitation". Circulation. 112 (1): 125–134. doi: 10.1161/CIRCULATIONAHA.104.488825 . ISSN   0009-7322. PMID   15998697.
  31. ↑ "Aortic Regurgitation. Health Information and treatment | Patient". Patient. Retrieved 2016-06-04.
  32. ↑ "Heart Failure Medication: Beta-Blockers, Alpha Activity, Beta-Blockers, Beta-1 Selective, ACE Inhibitors, ARBs, Inotropic Agents, Vasodilators, Nitrates, B-type Natriuretic Peptides, I(f) Inhibitors, ARNIs, Diuretics, Loop, Diuretics, Thiazide, Diuretics, Other, Diuretics, Potassium-Sparing, Aldosterone Antagonists, Selective, Alpha/Beta Adrenergic Agonists, Calcium Channel Blockers, Anticoagulants, Cardiovascular, Opioid Analgesics". emedicine.medscape.com. Retrieved 2016-06-04.
  33. 1 2 Wilson W, Taubert KA, Gewitz M, et al. (October 2007). "Prevention of Infective Endocarditis: Guidelines from the American Heart Association". Circulation. 116 (15): 1736–54. doi: 10.1161/CIRCULATIONAHA.106.183095 . PMID   17446442.
  34. ↑ Picano, Eugenio; Pibarot, Philippe; Lancellotti, Patrizio; Monin, Jean Luc; Bonow, Robert O. (2009-12-08). "The Emerging Role of Exercise Testing and Stress Echocardiography in Valvular Heart Disease". Journal of the American College of Cardiology. 54 (24): 2251–2260. doi: 10.1016/j.jacc.2009.07.046 . hdl: 2268/32855 . ISSN   0735-1097. PMID   19958961.
  35. ↑ Members, Committee; Klocke, Francis J.; Baird, Michael G.; Lorell, Beverly H.; Bateman, Timothy M.; Messer, Joseph V.; Berman, Daniel S.; O’Gara, Patrick T.; Carabello, Blase A. (2003-09-16). "ACC/AHA/ASNC Guidelines for the Clinical Use of Cardiac Radionuclide Imaging—Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASNC Committee to Revise the 1995 Guidelines for the Clinical Use of Cardiac Radionuclide Imaging)". Circulation. 108 (11): 1404–1418. doi: 10.1161/01.CIR.0000080946.42225.4D . ISSN   0009-7322. PMID   12975245.
  36. 1 2 Bonow, Robert O. (2013-02-19). "Chronic Mitral Regurgitation and Aortic Regurgitation". Journal of the American College of Cardiology. 61 (7): 693–701. doi: 10.1016/j.jacc.2012.08.1025 . ISSN   0735-1097. PMID   23265342.
  37. ↑ Carrel, Thierry (2009-01-01). "Aortic valve and/or aortic root replacement using an aortic homograft". Multimedia Manual of Cardio-Thoracic Surgery. 2009 (626): mmcts.2009.003905. doi:10.1510/mmcts.2009.003905. ISSN   1813-9175. PMID   24413404.
  38. ↑ Prendergast, Bernard D.; Tornos, Pilar (2010-03-09). "Surgery for Infective Endocarditis Who and When?". Circulation. 121 (9): 1141–1152. doi: 10.1161/CIRCULATIONAHA.108.773598 . ISSN   0009-7322. PMID   20212293.
  39. ↑ "Aortic Regurgitation / Aortic insufficiency information. Patient | Patient". Patient. Retrieved 2016-06-02.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.