M mode and two dimensional echocardiographic features of porcine valve dysfunction

Ball-valve thrombus obstructing a bioprosthetic mitral valve

We present a patient with a large, left atrial ball valve thrombus that was intermittently obstructing a bioprosthetic mitral valve. The diagnosis was confirmed by transesophageal two-dimensional echocardiogram. The transthoracic study initially had failed to demonstrate the true ball valve nature of the thrombus and instead, suggested two separate mass lesions, one in the left atrium and one in the bioprosthetic mitral valve.

Doppler and echocardiographic features of normal and dysfunctioning bioprosthetic valves

Echocardiographic and Doppler studies were performed on 183 clinically normal and 58 severely dysfunctioning bioprosthetic mitral, aortic and tricuspid valves. The valve dysfunction resulted from spontaneous cusp degeneration in 49 instances and from paravalvular regurgitation in 9. The pulsed Doppler study demonstrated regurgitant flow in 36 (92%) of 39 regurgitant valves and 8 (90%) of 9 paravalvular regurgitant valves. Diagnostic echocardiographic features were present in only 51 and 10% of the patients, respectively. Although the Doppler regurgitant jet was peripheral in seven of the nine patients with paravalvular regurgitation, it was not possible to differentiate these patients from those who had valve degeneration and cusp tear at the periphery of the valve ring. Eight patients presented with a musical holosystolic murmur of mitral insufficiency. In all eight there was a characteristic honking intonation on the audio signal and a striated shuddering appearance on the video Doppler signal. Ten stenotic mitral bioprosthetic valves (less than or equal to 1.1 cm2 valve orifice) were identified by Doppler study. Diagnostic echocardiographic features were present in only two of these patients. The Doppler-derived valve orifice dimension correlated well (r = 0.83) with cardiac catheterization values. Fourteen asymptomatic or minimally symptomatic patients had echocardiographically thickened mitral cusps (greater than or equal to 3 mm). These patients had a significantly (p less than 0.0001) smaller valve area as compared with normal control valves, and during 4 to 24 months of follow-up, five of these patients developed severe valve regurgitation or stenosis. Doppler ultrasound is more sensitive than echocardiography in diagnosing bioprosthetic valve stenosis and regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography in mitral valve disease: a review

Echocardiographic evaluation of the mitral valve has attracted much attention and generated much discussion since its beginnings, some thirty years ago. Echocardiography affords the physician a detailed assessment of mitral valve integrity unequalled by any other non-invasive test. Aside from the normal appearance of the valve, a variety of pathological conditions have been studied in detail; mitral stenosis was the first and over the years the state-of-the-art has evolved from simply looking at the EF slope as an indicator of severity to the accurate quantification utilizing planimetry and 'pressure half-time.' Mitral regurgitation, although not as well quantified as mitral stenosis, can be detected and its etiology usually determined. Mitral valve prolapse may easily be overdiagnosed by echocardiography, however together with auscultation, ultrasound remains the best way to evaluate this common condition. Echocardiography is also invaluable in the evaluation of endocarditis and prosthetic mitral valves.

Correlation of two-dimensional echocardiography and pathologic findings in porcine valve dysfunction

Two-dimensional echocardiographic findings in porcine valve dysfunction were compared with pathologic findings in 10 patients (12 valves). Three specific echocardiographic findings were identified in patients with regurgitant lesions: prolapse, fracture and flail leaflets. Prolapse was associated pathologically with thinning of the leaflets, longitudinal tears close to the ring margin and acid mucopolysaccharide accumulation. Valve fracture was seen with and without prolapse and was accompanied pathologically by small pinpoint perforations or tears of the leaflet. A flail leaflet was seen with a linear tear of the free margin and was associated with calcific deposits. Mild degrees of fracture seen pathologically were missed on the echocardiographic study in five patients. Thickening or calcification, when present in moderate or severe amounts, was correctly identified by echocardiography. When all abnormal features were considered collectively, two-dimensional echocardiography correctly identified at least one of them in all patients. Therefore, two-dimensional echocardiography may prove useful in assessing the source of valvular regurgitation in patients with bioprosthetic valves.

Huge left atrial thrombus and valve degeneration in a patient with a bioprosthetic, porcine, mitral valve

A 43 year old man with a Hancock porcine bioprosthetic valve in the mitral position developed a huge thrombus filling the entire left atrium and chronic degeneration of the bioprosthetic mitral valve. The effective valve orifice was less than 2 mm. These severe findings leading to the patient's death remained undetected while he was alive. This case illustrates the great need for a serial phonoechocardiographic studies in all patients with prosthetic valves.

Echocardiographic features of bioprosthetic valve endocarditis

Abnormal echocardiographic findings in seven cases of bioprosthetic valve endocarditis were confirmed in six at operation. The echocardiograms showed three cases with thickening and increased echo intensity (group 1) and four (group 2) in which vegetations were seen initially without either of the two features in group 1. Two patients in group 1 had vegetations, the causative organism being a streptococcus. Staphylococcus epidermidis was the causative organism in three of the four cases in group 2; in two of these rapidly growing vegetations were detected. The large vegetations obstructed the ostium of the bioprosthetic valve. Thus if vegetations are detected in cases in which staphylococci are the causative bacteria surgery should be performed as soon as possible. In patients who develop a fever after bioprosthetic valve replacement and especially in those with evident bacteraemia echocardiography should be repeated frequently so that lesions may be detected early.

Two-dimensional echocardiographic assessment of complications involving the Ionescu-Shiley pericardial valve in the mitral position

The function of the Ionescu-Shiley bovine pericardial xenograft in the mitral position was investigated in 70 patients by two-dimensional echocardiography. Echocardiographic data from 21 patients with suspected bioprosthetic dysfunction and 49 patients with normal clinical findings were analyzed in a double-blind fashion. Confirmation of cardiovascular status was obtained by means of cardiac catheterization, surgery, autopsy or other techniques in 19 of the 21 symptomatic patients. Two-dimensional echocardiography correctly evaluated bioprosthetic function in 98% of the patients. Six of the seven patients with proven xenograft dysfunction demonstrated echocardiographic evidence of malfunction. There was one false negative evaluation but no false positive results. Valve dysfunction included endocarditic mass lesions, mitral regurgitation resulting from dehiscence of a leaflet or the sewing ring or mitral stenosis due to calcification or malposition of the valve. This experience indicates that two-dimensional echocardiography is useful for assessing the Ionescu-Shiley mitral bioprosthesis, particularly in those patients who develop nonspecific symptoms.

Two-dimensional echocardiographic assessment of bioprosthetic valve dysfunction and infective endocarditis

Two-dimensional echocardiography of Hancock porcine heterograft valves was evaluated by correlation with clinical, hemodynamic, angiographic and pathologic findings in 80 patients. Ninety-five aortic and mitral bioprostheses were categorized by the type of valvular abnormality: group I, dysfunction due to primary tissue failure (41 valves); group II, dysfunction due to paravalvular leakage without infection (5 valves); group III, infective endocarditis with or without hemodynamic dysfunction (28 valves); and group IV, control cases without dysfunction or infection (21 valves). Increased size of a bioprosthetic leaflet image (minimal dimensions 3 x 5 mm) was observed in 46% (19 of 41) of cases with primary tissue failure and in 62% (10 of 16) of cases with leaflet vegetations due to endocarditis. Prolapse of leaflet echoes to below the level of the bioprosthetic sewing ring occurred in 76% (28 of 37) of cases with torn leaflets and also in 46% (6 of 13) of valves with vegetations on intact leaflets. Antegrade extension of leaflet echoes to beyond the level of the stents, observed in 4 of 16 cases with leaflet vegetations, was the only echocardiographic sign distinguishing leaflet infection from leaflet degeneration. Aortic bioprostheses with ring dehiscence affecting 40 to 90% of the anular circumference showed motion discordant with the motion of the adjacent aortic root and native anulus. Although echocardiographic abnormalities are frequently observed with bioprosthetic leaflet degeneration or infection, the echocardiographic appearance often does not distinguish between these two major complications and is best interpreted concurrently with other clinical and laboratory assessment.

Detection of deterioration or infection of homograft and porcine xenograft bioprosthetic valves in mitral and aortic positions by two-dimensional echocardiographic examination

Results of two-dimensional echocardiographic examinations were compared with angiographic, hemodynamic and surgical results in 44 patients with bioprosthetic valves in mitral and aortic positions who were undergoing elective or urgent reinvestigation 24 to 87 months (mean 34) after implantation. In these patients, there were 18 homograft aortic valves in the aortic position, 9 stent-mounted homograft aortic valves in the mitral position, 13 porcine xenograft valves in the mitral position and 12 in the aortic position. Poor cusp support, gross fluttering and prolapse of cusps behind or below the anulus identified aortic insufficiency by two-dimensional echocardiography in six patients with an aortic homograft and four patients were identified with insufficiency of a stent-mounted aortic homograft in the mitral position. Two-dimensional echocardiographic examination revealed mitral stenosis in three patients with a porcine xenograft valve in the mitral position and suggested mitral insufficiency in two others. Bacterial endocarditis on homograft or porcine xenograft valves was associated with easily imaged vegetations by two-dimensional echocardiography in 10 patients. Despite difficulties in imaging valve cusps, and the skill required to obtain good echocardiographic images of bioprosthetic valves, significant valve deterioration or infected prostheses were quite effectively imaged by two-dimensional echocardiography in this study.

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 greater than or equal to 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.

Noninvasive evaluation of normal and abnormal prosthetic valve function

Noninvasive techniques are helpful in evaluating the function of mechanical prostheses and tissue valves. Combined phonocardiography and M-mode echocardiography together with cinefluoroscopy are the most useful noninvasive techniques in differentiating normal from abnormal metallic prosthetic valve function. The intensity of the opening and closing clicks and associated murmurs will depend on the type of prosthetic valve, the heart rate and rhythm and the underlying hemodynamic status. Arrhythmias or conduction disturbances, or both, may produce motion patterns that mimic some of the echocardiographic signs of malfunctioning prosthetic valves. Differentiation of thrombus formation or tissue ingrowth from paravalvular regurgitation or dehiscence is possible by noninvasive techniques. Disc variance, a potentially serious and lethal problem with the older Beall valves, can be readily detected by cinefluoroscopy and echophonocardiography. With regard to bioprosthetic valves, two-dimensional echocardiography is superior to M-mode echocardiography in detecting primary valve failure. In addition, detection of vegetations, valve alignment and ring and individual leaflet motion can be best accomplished by two-dimensional echocardiography. Of greater importance is the patient serving as his or her own control in the follow-up assessment of prosthetic valve function by noninvasive techniques.

M-Mode and 2-dimensional echocardiographic characteristics of the Ionescu-Shiley valve in the mitral and aortic positions

Using M-mode and 2-dimensional (2-D) echocardiography, ultrasonic features of the Ionescu-Shiley valve were characterized. A number 23 prosthesis was placed in a saline-filled chamber and subjected to pulsatile flow. Production of a linear tear at the base of a cusp resulted in coarse fluttering in the open position, and there was a reduction in the anterior cusp slope. Partial detachment of a cusp from its stent produced high-amplitude low-frequency fluttering during ejection. Alteration of transducer position eliminated the abnormal echoes. Fourteen patients with aortic and 11 with mitral prostheses were studied. There was a close approximation of echographically determined values for the bare stent internal diameter, cusp excursion, and valve orifice diameter compared with the manufacturer's specifications. Random punctiform echoes were noted when the cusps opened. Cusp echoes were superimposed on stent echoes in 21% of patients, and a third cusp was detected in 29%. Two-dimensional echocardiograms of good quality were recorded in the vast majority of subjects. Cusp echoes were smooth and had a consistent motion in both the short and longitudinal axis. Multiple transducer positions were required to delineate prosthetic components with optimal clarity. It is concluded that (1) M-mode and 2-D echocardiography is useful in assessing Ionescu-Shiley valve function, (2) in vitro valve tears or detachment produces characteristic cusp fluttering, (3) careful attention to transducer positions is necessary to record high-quality valve images, and (4) these findings represent a data base for the longitudinal follow-up study of patients with the Ionescu-Shiley valve.

Echo-phonocardiographic features of regurgitant porcine mitral and tricuspid valves presenting with musical murmurs

Echophonographic findings of three patients with spontaneous degeneration of porcine tricuspid and mitral valves presenting with musical murmurs are reported. Echocardiography in all these patients revealed systolic or diastolic cusp flutter similar in frequency to the musical murmur on simultaneously recorded phonocardiogram. Porcine tricuspid regurgitation is usually well tolerated and can be followed clinically for many years. However, patients with mitral porcine valves usually become symptomatic or present with congestive heart failure and usually require valve surgery soon after clinical or echo-phonocardiographic findings of valve regurgitation appear.

Left ventricular outflow obstruction after aortic valve replacement: detection with continuous wave Doppler ultrasound recording

A 33 year old woman developed left ventricular outflow obstruction due to a fibrous subvalvular membrane 2 years after insertion of a Hancock modified orifice, porcine aortic valve prosthesis. M-mode and two-dimensional echocardiographic studies failed to detect the membrane. Continuous wave Doppler study revealed a maximal velocity of 4.8 m/s and a calculated peak pressure gradient of 92 mm Hg between the left ventricle and aorta. This finding was in close agreement with the peak gradient of 100 mm Hg obtained at cardiac catheterization. Because of its ability to accurately measure valvular gradients, continuous wave Doppler ultrasound study appears to be a useful noninvasive technique in the evaluation of patients with suspected prosthetic valve dysfunction.

Two-dimensional echocardiographic evaluation of mitral bioprosthetic function in infants and children

Two-dimensional echocardiography (2DE) was performed on 13 bioprosthetic mitral valves in 11 pediatric patients, 1 week to 46 months following implantation. Cardiac catheterization confirmed the echocardiographic findings of seven valves. The 11 normally functional bioprosthetic mitral valves by 2DE had leaflet thickness not exceeding 2.0 mm, freely moving leaflets, and normal sewing ring motion. The left atrium (LA) was enlarged only in the presence of mitral valve obstruction, atrial fibrillation, or left ventricular (LV) dysfunction. One bovine valve was stenotic due to fibrous tissue beneath normal valve leaflets; 2DE demonstrated limited leaflet motion, tissue beneath a thin valve leaflet, increase rocking motion of the sewing ring, and LA enlargement. In another patient, a bovine valve produced subaortic LV obstruction due to growth of fibrous tissue outside the stent; 2DE showed that the valve leaflets were thin and moved normally without excessive rocking of the valve ring, and identified the abnormal fibrous tissue in the LV outflow tract.

Echocardiographic changes in the thickness of porcine valves with time

To assess the ability of M-mode echocardiography to detect the incidence and frequency of porcine xenograft valve thickening, echocardiograms were obtained in 147 mitral and aortic porcine xenograft valves implanted in 131 patients. The patients were divided into an early group in whom the echocardiograms were performed within two months of valve replacement, and intermediate group studied two to 48 months after surgery, and a late group 48 months or longer after surgery. The porcine cusp echoes were visualized with proper gain settings, enlarged, and then recorded on a strip chart. The mean thickness of both the mitral and the aortic cusps was measured with the valve in the coapted position. The mean thickness of the porcine mitral valve increased from 1.23 +/- 0.12 in the early group to 2.3 mm +/- 0.19 in the late group (P less than .02). Aortic valve thickness increased from 0.91 mm +/- 0.07 in the early group to 2.1 mm +/- 0.37 (P less than .05) in the late group. A significant change in valve thickness was not observed in the intermediate group. In the late group of valves, 21/82 (27 percent) had a thickness greater than 3 mm. Nine of these valves (43 percent) have required replacement because of clinical dysfunction. Only 1.6 percent (1/61) of the valves in the late group with a thickness of less than 3 mm had or developed severe porcine valve insufficiency (P less than 0.001). In all ten instances, the echocardiographic assessment of valve thickness was validated on gross examination of the valve removed at surgery. This study indicates that the thickness of both mitral and aortic porcine valves can be measured by M-mode echocardiography. Valve thickness increases after 48 months and those valves with thickening of 3 mm or more are at a higher risk of developing clinical evidence of valve dysfunction.

Frequency of the first heart sound in the assessment of stiffening of mitral bioprosthetic valves

The frequency spectrum of the first heart sound (S1) was measured noninvasively in 54 patients with porcine bioprosthetic valves inserted in the mitral position. Phonocardiograms were recorded on magnetic tape on line with a signal processor with which the frequency spectrum and peak frequency of S1 were determined. In 19 patients with normal natural mitral valves, the apparent peak frequency within the range of measured frequencies of S1 was 46 +/- 2 Hz (mean +/- SEM). In 11 patients with porcine bioprosthetic valves implanted in the mitral position for less than or equal to 11/2 years, the apparent peak frequency of S1 was 43 +/- 3 Hz, which was not significantly different from S1 in patients with normal mitral valves. However, in 33 patients with porcine bioprosthetic valves in place 5-7 years, the apparent peak frequency of S1 was higher, 67 +/- 2 Hz (p < 0.001). In patients in whom the porcine bioprosthetic valve was implanted 5 years or longer, the frequency spectrum of S1 showed a greater proportion of sound energy at frequencies between 50-200 Hz compared with patients in whom the prosthetic valve was implanted 11/2 years or less. changes of the frequency of S1 in these patients may be a manifestation of stiffening of the valve as a result of early degenerative changes.

Echocardiographic features of a stenotic porcine aortic valve

M-mode and two-dimensional echocardiographic features are reported in a patient who developed stenosis of a porcine xenograph valve implanted in the aortic position. The presence of increased cusp echoes along with reduced cusp opening was the most consistent echocardiographic finding in this patient. The clinical and the echocardiographic findings were subsequently confirmed by cardiac catheterization and surgery.

Spontaneous degeneration of porcine bioprosthetic valves

From October, 1971, to October, 1979, 490 patients with 560 porcine bioprosthetic valves were discharged from the hospital. During these 8 years, 23 valves were removed because of failure due to spontaneous degeneration. Bioprosthetic valve survival without degeneration was at 4 years, 98.9% +/- 86 (standard error); at 5 years, 96.4% +/- 1.3; at 6 years, 90.8% +/- 2.4; and at 7 years, 84.2% +/- 3.7. There was no difference in degeneration observed with regard to sex, valve position, or whether the valves were rinsed with antibiotics prior to implantation. There was an increase in degeneration in patients 35 years old and younger compared with those more than 35 years old (p = 0.0001). Valve failure was gradual, and valve changes were noted by echocardiogram and phonocardiogram prior to actual failure. Specific factors leading to degeneration require further investigation.

Porcine xenograft valves. Long-term (60-89-month) follow-up

An analysis of 211 patients who had porcine xenograft valve replacements at Henry Ford Hospital between October 1971 and March 1974, was accomplished, with 100% follow-up. The follow-up period extended from 60-89 months after implantation. One hundred sixty-seven patients with 192 valves survived the perioperative period and were subjected to life table analysis. Hemodynamically significant porcine xenograft degeneration that required reoperation occurred in 18 patients, two of whom had infective endocarditis. Only four valves failed within 48 months of surgery. Ten of 42 (23.8%) patients with isolated aortic valve replacement and eight of 102 patients (7.8%) patients with isolated mitral valve replacement required reoperation (p < 0.01). In patients under 25 years of age, six of nine surviving patients had repeat operations. Our data indicate that porcine xenograft degeneration is related to the duration of implantation and the age of the patient at the time implantation was performed. In addition, porcine xenograft valves in the aortic position are more likely to degenerate than are those in the mitral position.

Severe calcification of glutaraldehyde-preserved porcine xenografts in children

Despite the widespread use of glutaraldehyde-preserved porcine xenografts, severe short-term calcification of these valves has been infrequently reported. This report describes four cases of glutaraldehyde-preserved porcine xenografts in the mitral valve position in which severe calcification occurred within 17 to 25 months of implantation. All four patients were children, aged 13 to 15 years. The clinical presentation in all four cases occurred at a late stage when there was severe xenograft obstruction, with acute symptoms of cardiac decompensation in the presence of pulmonary hypertension and right heart failure. There was rapid cardiac deterioration resulting in a low output state and episodic pulmonary edema necessitating urgent mitral valve replacement. In only one case was there clear auscultatory evidence of severe mitral stenosis. Calcification of these xenografts occurred in the presence of normal serum calcium levels and was not related to infective endocarditis. Histologic examination of the calcified xenografts strongly suggested dystrophic calcification resulting from primary collagen degeneration. The exact cause is unclear, but it appears that glutaraldehyde-preserved porcine xenografts may produce severe short-term calcification with acute hemodynamic deterioration necessitating urgent valve replacement and that this accelerated calcification may be a complication in young persons,