Acute Valvular Regurgitation
Authors: Karen K. Stout, Edward D. Verrier
Journal: Circulation (2009)

A cute severe valvular regurgitation is a surgical emer- gency, but accurate and timely diagnosis can be difficult.Although cardiovascular collapse is a common presentation, examination findings to suggest acute regurgitation may be subtle, and the clinical presentation may be nonspecific.Consequently, the presentation of acute valvular regurgitation may be mistaken for other acute conditions, such as sepsis, pneumonia, or nonvalvular heart failure.Although acute regurgitation may affect any valve, acute regurgitation of the left-sided valves is more common and has greater clinical impact than acute regurgitation of right-sided valves.Data to guide appropriate management of patients with acute regurgitation are sparse; there are no randomized trials, and much of the literature describes either small series or the experiences of specific centers.Despite these limitations, the available data are sufficient to allow identification of general principles as well as development of applicable guidelines from both the American College of Cardiology/American Heart Association and European Society of Cardiology.2][3] The data and guidelines emphasize overarching clinical principles, including the need for a high clinical suspicion of acute regurgitation, timely use of echocardiography, and, in the majority of patients, rapid progression to surgery. CausesCauses of acute regurgitation overlap with causes of chronic regurgitation and vary depending on the valve affected (Table 1).Endocarditis may affect either the aortic or mitral valve, whereas other causes are unique to the specific valve involved.The majority of causes of acute regurgitation present as an acute or subacute event.However, acute regurgitation can occur in patients with chronic regurgitation, when regurgitant severity is exacerbated by factors such as coronary ischemia, chordal rupture, or leaflet perforation from endocarditis.Acute regurgitation of either the aortic or mitral valve may result from procedural complications of percutaneous valve procedures.In addition, acute prosthetic valve regurgitation is seen more frequently as more patients undergo valve surgery.Acute prosthetic valve regurgitation is usually due to a tear of a bioprosthetic leaflet 4 or thrombosis of a mechanical valve, although perivalvular regurgitation can occur, particularly in prosthetic valve endocarditis.Acute aortic regurgitation is most commonly due to endocarditis, but there are a variety of less common causes as well.Aortic dissection, whether due to Marfan syndrome, bicuspid aortic valve, or atherosclerotic disease, may present with aortic regurgitation.Blunt trauma may result in leaflet rupture. 5Another less common cause is rupture of a fenestration in the aortic leaflet. 6cute mitral regurgitation may result from either "organic" or "functional" causes.Organic causes are those that result in permanent structural disruption of the valve, such as leaflet perforation from endocarditis, chordal rupture in myxomatous valve disease, or papillary muscle rupture due to myocardial infarction.Functional mitral regurgitation results from abnormalities of the left ventricle, such as cardiomyopathies in which the papillary muscles are laterally displaced, or acute ischemia, in which an akinetic wall segment and papillary muscle impair mitral valve closure.The distinction between organic and functional causes is an important one because treatment of organic causes requires surgical repair, whereas functional causes may improve with treatment of the underlying myocardial ischemia, infarction, or cardiomyopathy.Functional mitral regurgitation is more often chronic than acute.However, processes that result in rapid decline of ventricular function may cause acute functional mitral regurgitation as part of the presentation of acute heart failure.8][9] Emphasizing the variability in pathological process, a study demonstrated that mitral regurgitation in Takotsubo cardiomyopathy can result from outflow tract obstruction and systolic anterior mitral leaflet motion due to apical ballooning with preserved basal ventricular function. 9Rheumatic carditis can cause acute mitral regurgitation through a combination of leaflet inflammation and myocardial dysfunction, with some data suggesting that the degree of valve dysfunction drives outcomes. 10Although uncommon in industrialized nations, acute rheumatic carditis remains a significant issue in developing countries.