Pathology of mitral valve stenosis and pure mitral regurgitation—Part II

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant mitral valves. in Part I, conditions producing mitral valve stenosis were reviewed. in over 99% of stenotic mitral valves, the etiology is rheumatic disease. Other rare causes of mitral stenosis include congenitally malformed valves, active infective endocarditis, massive annular calcium, and metabolic or enzymatic abnormalities. in Part II, conditions producing pure mitral regurgitation are discussed. in contrast to the few causes of mitral stenosis, the causes of pure (no element of stenosis) mitral regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy mitral valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and ruptured chordae tendineae.     

Pathology of mitral valve stenosis and pure mitral regurgitation—Part I

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant mitral valves. In Part I, conditions producing mitral valve stenosis are reviewed. In over 99% of stenotic mitral valves, the etiology is rheumatic disease. Other rare causes of mitral stenosis include congenitally malformed valves, active infective endocarditis, massive annular calcium, and metabolic or enzymatic abnormalities. In Part II, conditions producing pure mitral regurgitation will be discussed. In contrast to the few causes of mitral stenosis, the causes of pure (no element of stenosis) mitral regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy mitral valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and ruptured chordae tendineae.     

Pathology of tricuspid valve stenosis and pure tricuspid regurgitation—Part II

This three-part article examines the histologic and morphologic basis for stenotic and purely regurgitant tricuspid valves. In Part I, conditions producing tricuspid valve stenosis were reviewed. In Part II, conditions producing pure tricuspid regurgitation are discussed. In contrast to the relatively few causes of tricuspid stenosis, the causes of pure (no element of stenosis) tricuspid regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy tricuspid valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and Ebstein's anomaly.     

二叶主动脉瓣的超声分析

目的 探讨二叶主动脉瓣的超声心动图特征。方法 采用回顾性方法分析了26例先天性二叶主动脉瓣,其中主动脉瓣狭窄17例（有或无主动脉瓣关闭不全）和单纯主动脉瓣关闭不全9例。结果 在主动脉瓣狭窄组、轻度狭窄14例（82％）;二叶主动脉瓣感染性心内膜炎的发生率为42％;主动脉瓣狭窄组与单纯主动脉瓣反流组相比,主动脉瓣增厚钙化有极显性差异（P＜0．00005）,结果表明,二叶主动脉瓣狭窄的发生与主动脉瓣的增厚钙化有关,且主动脉瓣狭窄多为轻度狭窄。结论：二叶主动脉瓣狭窄的发生与主动脉瓣的增厚钙化有关,且主动脉瓣狭窄多为轻度狭窄。二叶主动脉瓣感染性心内膜炎的发生率较高。彩色多普勒二维超声心动图对二叶主动脉瓣的诊断具有重要价值。     

Pathology of tricuspid valve stenosis and pure tricuspid regurgitation—Part I

This three-part article examines the histologic and morphologic basis for stenotic and purely regurgitant tricuspid valves. In Part I, conditions producing tricuspid valve stenosis are reviewed. In over 90% of stenotic tricuspid valves, the etiology is rheumatic disease. In isolated tricuspid stenosis, the etiology is either carcinoid or congenital. Rare causes of tricuspid stenosis include active infective endocarditis, metabolic or enzymatic abnormalities (Fabry's, Whipple's disease), and giant blood cysts.     

Rare or unusual causes of chronic, isolated, pure aortic regurgitation

Six patients undergoing aortic valve replacement had rare or unusual causes of isolated, pure aortic regurgitation. Two patients had congenitally bicuspid aortic valves with a false commissure (raphe) displaced to the aortic wall ("tethered bicuspid aortic valve"), two had floppy aortic valves, one had a congenital quadricuspid valve, and one had radiation-induced valve damage.     

Etiology of aortic valve disease and recent changes in Japan:a study of 600 valve replacement cases

BACKGROUND: Recent studies on the etiology of aortic valve disease in the US showed a decrease in rheumatic valve disease and an increase in age-related degenerative disease. The purpose of this study was to describe the etiology of aortic valve disease and its temporal changes in Japan, based on a large number of cases. METHODS: The medical charts of all patients who underwent aortic valve replacement at our institute between 1977 and 1999 were reviewed. Among the 600 patients analyzed, 213 (36%) had pure aortic stenosis, 265 (44%) had pure aortic regurgitation, and 122 (20%) had combined stenosis and regurgitation. RESULTS: The causes were rheumatic change (49%), degenerative change (19%), bicuspid valves (18%), infective endocarditis (5%) and others (9%). Rheumatic disease continued to be the most common cause of aortic stenosis, but its frequency decreased from 100% in 1977-1979 to 37% in 1995-1999. In contrast, the frequency of degenerative change among stenotic valves increased recently from 11% in 1990-1994 to 30% in 1995-1999. Similarly, rheumatic disease remained to be the leading cause of aortic regurgitation, with a decline in frequency from 46% in 1985-1989 to 27% in 1995-1999. The percentage of degenerative change among regurgitant valves did not change appreciably. CONCLUSIONS: There was a shift in the causes of aortic valve disease, with a decrease in rheumatic disease and an increase in degenerative disease. This trend was similar to that observed in the US. These findings suggest the increasing importance of aortic valve disease due to degenerative change.     

A rare mechanism of aortic regurgitation in a young patient

A 19‐year‐old male patient was admitted to our institute with dyspnea. His medical history had no rheumatic fever or infective endocarditis. Physical examination revealed a diastolic murmur over the aortic area, rales of bilateral lungs. Bedside transthoracic echocardiography (TTE) revealed a severe aortic regurgitation (AR) without aortic valve stenosis and a moderately dilated left ventricle accompanied by an ejection fraction of 55%. The aortic valve could not be clearly demonstrated as either bicuspid or tricuspid. Congenital AR typically occurs in conjunction with an additional cardiac abnormality or aortic valve stenosis. Furthermore, bicuspid aortic valves are observed in the majority of patients. The aortic valve is created from the truncus ridge of the truncus arteriosus while the embryological development.     

Presence of a congenitally bicuspid aortic valve among patients having combined mitral and aortic valve replacement

Although bicuspid aortic valve occurs in an estimated 1% of adults and mitral valve prolapse in an estimated 5% of adults, occurrence of the 2 in the same patient is infrequent. During examination of operatively excised aortic and mitral valves because of dysfunction (stenosis and/or regurgitation), we encountered 16 patients who had congenitally bicuspid aortic valves associated with various types of dysfunctioning mitral valves. Eleven of the 16 patients had aortic stenosis (AS): 5 of them also had mitral stenosis, of rheumatic origin in 4 and secondary to mitral annular calcium in 1; the other 6 with aortic stenosis had pure mitral regurgitation (MR) secondary to mitral valve prolapse in 3, to ischemia in 2, and to unclear origin in 1. Of the 5 patients with pure aortic regurgitation, each also had pure mitral regurgitation: in 1 secondary to mitral valve prolapse and in 4 secondary to infective endocarditis. In conclusion, various types of mitral dysfunction severe enough to warrant mitral valve replacement occur in patients with bicuspid aortic valves. A proper search for mitral valve dysfunction in patients with bicuspid aortic valves appears warranted.     

Acute aortic regurgitation due to spontaneous rupture of a bicuspid aortic valve: detection by echocardiography

A 42-year-old man was admitted with acute severe aortic regurgitation. There were no signs of a systemic infection. M-mode and two-dimensional echocardiography revealed bicuspid aortic valve and echocardiographic features consistent with aortic leaflet rupture. The diagnosis was confirmed at surgery. This report illustrates that spontaneous rupture of a bicuspid aortic valve should be considered in acute aortic regurgitation without infective endocarditis.     

Congenitally bicuspid aortic valve causing severe,pure aortic regurgitation without superimposed infective endocarditis: Analysis of 13 patients requiring aortic valve replacement

Although stenosis and infective endocarditis are commonly appreciated complications of the congenitally bicuspid aortic valve, pure severe aortic regurgitation complicating this congenital malformation, unassociated with either stenosis or infection, is not well recognized. Among 189 patients who had aortic valve replacement at the National Heart, Lung, and Blood institute because of isolated pure aortic regurgitation, the congenitally bicuspid aortic valve, never the site of infective endocarditis, was responsible for the aortic regurgitation in 13 (7 percent). This report describes certain clinical and morphologic findings in 13 men, aged 26 to 65 years (mean 43), who required aortic valve replacement because of severe aortic regurgitation secondary to a noninfected, nonstenotic congenitally bicuspid aortic valve. Although not generally recognized, the noninfected congenitally bicuspid aortic valve is an important cause of pure aortic regurgitation severe enough to warrant aortic valve replacement.     

Retinal embolization of bicuspid aortic valve calcification

We report the case of a 36-year-old man with calcified bicuspid aorta. Aortic disease was diagnosed after retinal embolism, which caused loss of vision affecting the left eye. Doppler examination did not identify carotid stenosis. Transthoracic echocardiography showed thickness and calcification of two leaflets, moderate aortic regurgitation, high normal left ventricular diastolic dimensions, and high normal interventricular septum thickness. Parasternal long-axis view in the systolic frame showed dilated left ventricular outflow tract, dilated ascending aorta, and calcification and thickening of aortic leaflets, causing an echo-lucent area, in the diastolic frame. It also showed the eccentric position of the closed valve leaflets, short axis in the diastolic frame, and the absence of the typical "Y" letter sign, tracked by the three leaflets (septal, right coronary, and left coronary) in the normal tricuspid aortic valve. On long-axis parasternal acquisition, we note high normal interventricular septum thickness and high normal diastolic diameter. Color Doppler analysis from the apical five-chamber view showed aortic regurgitation; regurgitant jet area was about 44% of the outflow tract, so aortic regurgitation was classified as moderate. Pulsed Doppler showed a high normal value of peak aortic velocity. Transesophageal echocardiography was performed, but no further findings were identified. We think that the likely retinal embolism sources were the aortic calcified leaflets, even if the aortic valve was not stenotic and with no signs of endocarditis. However, because we cannot exclude other potential causes, we put the patient on anticoagulant therapy. Furthermore, aortic valve replacement was not advised.     

Mixed aortic valve disease treated with transcatheter aortic valve replacement in a high risk patient presenting with acute decompensated heart failure

Mixed aortic valve disease refers to the combination of aortic regurgitation (AR) and aortic stenosis (AS). Commonly etiologies include a bicuspid aortic valve, rheumatic heart disease, and endocarditis superimposed upon a stenotic aortic valve. Treatment depends upon the severity of disease, the presence of symptoms and the size and function of the left ventricle. We present a case of a young patient that presented with new onset acute decompensated heart failure with mixed aortic valve disease that was successful treated with transcatheter aortic valve replacement (TAVR). Invasive hemodynamics at baseline and following TAVR provide an insight into the characteristic features of mixed aortic valve disease. TAVR represents a new treatment option for critically ill patients deemed high risk or nonoperable for surgical aortic valve replacement.     

Impact of valvular calcification on the diagnostic accuracy of transesophageal echocardiography for the detection of congenital aortic valve malformation

BACKGROUND: Degeneration of congenital bicuspid or unicuspid aortic valves can progress more rapidly than that of tricuspid valves, and an early diagnosis significantly impacts decision making and outcome. We hypothesized that the extent of valvular calcification would negatively influence the diagnostic accuracy of multiplane transesophageal echocardiography (TEE) for the diagnosis of congenital aortic valve disease. METHODS: TEE was performed in 57 patients undergoing aortic valve replacement surgery for aortic stenosis (n = 46), pure regurgitation (n = 9), or significant regurgitation with less than severe aortic stenosis (n = 2). The degree of aortic valve calcification and the number of valve cusps were determined at surgery. RESULTS: Surgical inspection confirmed 14 bicuspid and 43 tricuspid aortic valves. Sensitivity and specificity of TEE for the diagnosis of congenital aortic valve malformation was 93% (13/14) and 91% (39/43) (P = 0.0001), respectively. In patients with no or mild aortic valve calcification (n = 13), sensitivity and specificity of TEE for the diagnosis of congenitally malformed aortic valve was 100% (5/5) and 100% (8/8) (P = 0.001), respectively. In patients with moderate or marked aortic valve calcification (n = 44), sensitivity and specificity of TEE for the diagnosis of congenitally malformed aortic valve was 89% (8/9) and 89% (31/35) (P<0.0001), respectively. In this subgroup of 44 patients, there were four false-positive and one false-negative diagnoses due to valvular calcification. CONCLUSIONS: Although TEE is highly sensitive and specific for the detection of congenital aortic valve malformations, presence of moderate or marked calcification of the aortic valve may result in false positive and false negative diagnoses.     

Myxoid degeneration of the aortic valve and isolated severe aortic regurgitation

Clinical and pathologic data were reviewed in 55 patients who had valve replacement for pure aortic regurgitation (AR) during a 6-year period. The clinical histories established the cause for AR in 34 cases: 11 rheumatic, 13 infective endocarditis, 4 congenital, 4 associated with aortic aneurysms and 2 the Marfan syndrome. In the valves from the other 21 patients, 13 had myxoid degeneration, defined as significant disruption of the valve fibrosa and its replacement by acid mucopolysaccharides and cystic change. Myxoid degeneration was also the primary pathologic abnormality in the 2 patients with the Marfan's syndrome, in 3 patients with a history of rheumatic disease and in 1 patient with a history of infective endocarditis. The patients with myxoid degeneration of uncertain origin were predominantly elderly (average age 63 years), had a long-standing history of systemic hypertension (77%) and had coronary artery disease (46%); 85% were male. In these patients the replacement valves were not larger than those of the other groups studied, indicating that dilatation of the aortic anulus was not a significant factor in the pathogenesis of the valve disease. These findings indicate that myxoid degeneration of the aortic valve is common (36% of all valves examined) and, in many cases, may be secondary to long-standing systemic hypertension.     

Bicuspid aortic valve morphology when associated with coarctation of the aorta

Thirteen children and young adults with coarctation of the aorta as their principal cardiovascular abnormality, 11 with bicuspid aortic valves, were evaluated by orifice-view aortography to evaluate their aortic valvular morphology. For comparison 30 individuals with aortic valvular deformities but without coarctation of the aorta were similarly studied. Two distinct forms of bicuspid valves could be identified characterized by either the appearance of gross inequality of size of the two valve leaflets or an appearance wherein each leaflet closely approximated the size of the other, thus equally bicuspid. Excepting two individuals with normal, tricuspid, aortic valves, all of the patients with coarctation of the aorta had equally bicuspid aortic valves which contrasted to the group without coarctation in which the unequally bicuspid type predominated. This difference in bicuspid aortic valve morphology associated with coarctation of the aorta suggests a different developmental process involving the aortic valve as opposed to the situation in individuals without coarctation.     

Aortic valve morphology influences regurgitant volume in aortic regurgitation: in vitro evaluation

STUDY OBJECTIVE--According to the Gorlin hydraulic orifice equation, aortic regurgitation volume can be determined by the regurgitant orifice cross sectional area, diastolic filling period, mean pressure gradient between the aorta and left ventricle, and a constant relating the coefficients of contraction (Cc) and velocity (Cv). This study was performed to determine whether variation in aortic valve morphology affects regurgitant flow volume, Cc and Cv. DESIGN--Four aortic valve templates, modelled after circular, rheumatic, degenerative, and bicuspid lesions, were constructed with equal orifice cross sectional areas in two sizes, 0.2 and 0.7 cm2. These valves were studied in vitro in a flow model of aortic regurgitation, wherein aortic pressure was regulated by varying the height of a column of fluid. Flow, pressure, and velocity were measured, and the coefficient Cc and Cv were calculated from standard equations. MEASUREMENTS AND MAIN RESULTS--Regurgitant volume was assessed at diastolic filling periods of 0.5 and 1.0 s and averaged 15% greater for bicuspid and degenerative as compared to circular or rheumatic valve shapes (p = 0.0001). This difference was accentuated at the shorter diastolic filling time and higher pressure gradient, such that bicuspid lesions allowed 29% more regurgitant flow across the 0.2 cm2 orifice at fluid height of 120 cm over 0.5 s. This difference in regurgitant volume between valve shapes was due to an increased Cc for the bicuspid and degenerative valve shapes, suggesting that they are more efficient orifices than rheumatic or circular valve shapes. CONCLUSIONS--Aortic valve morphology influences regurgitant volume in aortic regurgitation. Specifically, degenerative and bicuspid orifice shapes have a higher contraction coefficient and allow more regurgitant flow than rheumatic or circular orifices at a given driving pressure and diastolic filling time.     

Pathology of pulmonic valve stenosis and pure regurgitation

Little morphologic information is available on operatively excised pulmonic valves. The causes of pulmonic stenosis are limited to a few conditions: (1) rheumatic and (2) non-rheunatic (congenital, carcinoid, infective endocarditis). Congenital causes of pulmonic stenosis constitute well over 95% of these conditions. Congenital types of pulmonic stenosis include acommissural dome-shaped, dysplastic, and bicuspid. Rare acquired causes of pulmonic stenosis include carcinoid, rheumatic, and infective endocarditis. Of the acquired causes of pulmonic stenosis, carcinoid is the most common condition. In contrast, causes of pure pulmonic regurgitation are multiple. Two major categories of pure pulmonic regurgitation include (1) conditions associated with anatomically abnormal valve cusps (congenital, rheumatic, carcinoid, trauma, and infective endocarditis) and (2) conditions associated with anatomically normal cusps (elevated pulmonary artery systolic pressures, idiopathic dilated pulmonary trunk, and Marfan's syndrome).     

Echocardiographic evaluation of porcine bioprosthetic valves: Experience with 309 normal and 59 dysfunctioning valves

To determine the clinical value of echocardiographic evaluation of porcine bioprosthetic valves, the findings in all patients who had porcine bioprosthetic valve replacement and adequate quality echocardiographic studies from 1978 to 1982 were analyzed. The study includes 309 normal and 59 dysfunctioning valves. Valve dysfunction resulted from spontaneous cusp degeneration in 39 (34 valve regurgitations, 5 stenoses), infective endocarditis in 12, paravalvular regurgitation in 5, regurgitation of redundant cusps, mitral valve thrombi, and aortic stent stenosis in 3 others. Echocardiographic findings were correlated with gross surgical pathologic or autopsy findings in 45 of the 59 dysfunctioning valves. Echocardiographic abnormalities were demonstrated in 41 of 59 (69%) dysfunctioning valves. A systolic mitral or diastolic aortic valve flutter was diagnostic of a regurgitant valve caused by a torn or unsupported cusp margin and was observed in 28 of 34 (82%) regurgitant valves with no false-positive studies. Echocardiographic cusp thickness of ≥ 3 mm correctly identified all regurgitant and stenotic valves with gross anatomic evidence of localized or generalized cusp thickening or calcific deposits. Echocardiographic valve abnormalities were observed in only 4 of 12 patients with infective endocarditis and in 1 of 5 with paravalvular regurgitation.Thus, echocardiography provides important information regarding the function of porcine bioprosthetic valves and is of value in the decision to replace these valves, especially when dysfunction is due to spontaneous cuspal degeneration. Echocardiography is neither sensitive nor specific in patients with infective endocarditis and paravalvular regurgitation.     

Clinical characteristics of bicuspid aortic valves in surgical patients

Of 413 patients undergoing surgery for aortic valve disease, 42 were confirmed to have congenital bicuspid aortic valve. There were 24 males and 18 females, with a mean age of 54.9 +/- 14.6 years. The etiology of the surgical indications in patients with bicuspid valves were degeneration, rheumatic disease, and infectious endocarditis. Thirty-two patients had aortic stenosis and 10 had aortic regurgitation. Infective endocarditis was seen mainly in patients < or =50 years of age at the time of surgery, while degenerative aortic stenosis occurred more often in older patients. The annular diameter measured during surgery was significantly narrower in the 42 patients with bicuspid valves compared to 371 patients with tricuspid valves who underwent aortic valve replacement during the same period. It is important to prevent infectious endocarditis in younger patients diagnosed with bicuspid aortic valve, whereas careful attention should be paid to decalcification during surgery in older patients because the vast majority suffer from degenerative aortic stenosis.