Conservative operation for infective endocarditis of the mitral valve

BACKGROUND: Subvalvular preservation is necessary to maintain left ventricular function, but accidental retention of infected tissue could cause postoperative endocarditis. METHODS: We examined 71 consecutive patients who underwent operation for mitral endocarditis. Endocarditis was uncontrolled and active in 24 patients, partially treated (unfinished antibiotic course) in 17, and healed in 30. RESULTS: Valves were repaired in 17% versus 59% versus 63% and replaced with subvalvular preservation in 25% versus 6% versus 3% of the uncontrolled active, partially treated, and healed groups, respectively. Thirty-day mortality was 29% versus 0% versus 3.3% (p=0.003), total mortality was 46% versus 18% versus 17% (p=0.035), and complications-related mortality was 38% versus 11% versus 13% (p=0.054), respectively. There was a trend toward lower complications-related mortality with subvalvular preservation than without. Postoperative endocarditis occurred in 3 of 30 patients without and 1 of 41 patients with subvalvular preservation. CONCLUSIONS: Postoperative mortality in uncontrolled active mitral endocarditis remains high, but results are good with partially treated or healed endocarditis. Subvalvular preservation improves outcome, does not increase postoperative endocarditis rates, and should be performed whenever feasible.     

Transesophageal echocardiography in the detection and surgical management of a papillary fibroelastoma of the mitral valve causing partial mitral valve obstruction

Duchenne muscular dystrophy (DMD) is an X-chromosome-linked myopathy caused by a defect in the DMD gene. Intragenic deletions appear to be the most common gene defect leading to DMD, and the deletion frequency has been estimated to be 66%. Results of this study using a group of 24 DMD patients of Sri Lankan origin employing the technique of multiplex DNA amplification using the polymerase chain reaction indicated a deletion frequency of 62.5%. Eighty per cent of these deletions were localized in a region of the DMD gene regarded as a 'hot spot' for DMD deletions. Our results are in agreement with the results of other studies carried out on Caucasian populations.     

Clinical and health care cost consequences of infective endocarditis in mitral valve prolapse

In 1990-1991, a national survey was conducted to estimate the prevalence of Salmonella species among Canadian commercial turkey flocks. Two hundred and seventy flocks were randomly selected across Canada. The proportion sampled from each province was selected according to each province's share of the national turkey market. Samples, consisting of 12 pooled litter and four pooled dust samples, were used to determine the Salmonella status of the environment of each flock. Additionally, a one kilogram sample of feed was taken from each flock premise. Salmonella was recovered from environmental samples in 234/270 (86.7%) of flocks and from feed samples in 26/266 (9.8%) of flocks. Forty-eight different Salmonella serovars were isolated from flock environmental samples. The most prevalent serovars were S. anatum, S. hadar, S. agona, S. heidelberg and S. saintpaul which were isolated from 53/270 (19.6%), 49/270 (18.1%), 49/270 (18.1%), 42/270 (15.6%) and 34/270 (12.6%) flocks, respectively.     

Enterococcal infective endocarditis on native aortic valve

Enterococcal endocarditis accounts for 10% of all bacterial endocardits. The infection progresses in a subacute way and when localized on the aortic valve it has a very poor prognosis since the valve is usually destroyed being death the fatal outcome. We report a case of a patient with infective endocarditis resulting from the implantion of the Enterococcus on the native aortic valve. Nor visk factors or an apparent main gate could be found. The patient was hospitalized after several months of a non especific febrile syndrome. The literature is reviewed. Diagnostic tests and clinical signs are discussed making emphasis on the refractoriness to chemotherapy.     

Value and limitations of transesophageal echocardiography in infective endocarditis

Echocardiography has contributed considerably to the evolution in the management of patients with infective endocarditis. There is a clear hierarchy with respect to sensitivity of the different methods is superior when compared to 2-D and M-mode echocardiography in identifying both vegetations and perivalvular complications e.g. abscess formation, aneurysms, mural endocardial lesions. For patients with suspected endocarditis, in whom vegetations can not be clearly identified or in whom abscess formation is suspected with transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) with mono- or multiplane scans has become the standard diagnostic procedure. For the examination of prosthetic valves it is the method of choice. It has even been suggested that it is employed as routine measure in all patients with suspected infective endocarditis. TEE is a safe semi-invasive technique with an extremely low complication rate and high sensitivity. Its specificity depends largely on the patient group which is examined. In patients with indicative clinical symptoms the specificity and the predictive value of vegetations are high. When used as screening method to assess echodense formations at cardiac valves particularly in the elderly, in whom degenerative changes prevail, its specificity and positive predictive value of vegetation-like structures are much lower. The negative predictive value of a negative transesophageal echocardiogram remains high, however. Valve abscesses are detected rarely by transthoracic echocardiography. It is the domain of TEE to assess them particularly in the aortic and mitral valve area. For them the specificity and positive predictive value of TEE in the diagnosis of infective endocarditis is high again. Of further importance was the observation that patients with vegetations of > 10 mm were more likely to suffer embolic complications. It should be noted, however, that infective endocarditis remains a clinical diagnosis: neither is the demonstration of a vegetation already the equivalent of endocarditis, nor does missing vegetations completely rule out the possibility of it. But without doubt, the presence of vegetations, of abscess formation or a concomitant pericardial effusion add valuable information to clinical diagnosis of infective endocarditis, which still needs a "high index of suspicion".     

Abscess of the mitral-aortic confluence and perforation of the mitral valve in a patient with Brucella endocarditis]

We report a case of Brucella aortic valve endocarditis in a 36 year-old patient with no underlying heart disease who required urgent surgery. In the postoperative follow-up, he suffered from congestive heart failure due to an anterior mitral valve rupture. In the echocardiogram, a periprosthetic abscess was seen and a second intervention was necessary. This report suggests that treating Brucella endocarditis requires a combined medical and surgical approach.     

Apical cross-sectional echocardiography. Standard for the diagnosis of idiopathic mitral valve prolapse syndrome

In light of the nonspecificity of left ventricular angiography and physical examination, and the limitations of M-mode echocardiography to define the presence of mitral valve prolapse syndrome, we evaluated left ventricular longitudinal and apical four-chamber tomographic views of cross sectional echocardiography in 19 subjects with normal left ventricular cineangiography and in 5 patients with congestive cardiomyopathy. None had auscultatory findings suggestive of mitral valve prolapse syndrome. In all 24 control subjects, the apical view demonstrated the coaptation point and the leaflets of the mitral valve to lie inside the left ventricular cavity. A retrospective analysis of 900 consecutive cross sectional echocardiographic studies revealed 105 subjects with no evidence of structural heart disease other than the presence of the mitral valve leaflets in the left atrium in systole defining the existence of idiopathic mitral valve prolapse syndrome. Both mitral leaflets were prolapsed in 90 percent of the involved populations, and the apical tomographic cross sectional echocardiographic view was superior to the left ventricular longitudinal view for the detection of anterior leaflet prolapse. These data suggest that the apical cross sectional view may be the single best technique to define the presence of idiopathic mitral valve prolapse syndrome.     

Results of Biocor stentless valve replacement for infective endocarditis of the native aortic valve

The mid-term results in a selected group of 9 patients with native aortic valve endocarditis managed by aortic valve replacement (with or without complex annular reconstruction) using a totally biological stentless valve are outlined. At a mean follow-up of 48 months, there are currently 7 survivors (2 late noncardiac deaths) with 100% freedom from reoperation, valve-related complication, and endocarditis.     

A case of infective endocarditis with the mycotic aortic valve aneurysm

A 49-year old man was admitted with a complaint of syncopal attack. Transient A.V block was detected and permanent pacemaker (DDD) was implanted. Five months later he was re-admitted because of dyspnea and palpitation. Infective endocarditis with aortic regurgitation and mycotic aortic valve aneurysm was diagnosed by echocardiography and cineangiography. The aortic valve and valve aneurysm were resected and AVR was performed using Bj?rk-Shiley disc valve (23A) in the usual manner. But 6 months later he suffered from acute cardiac failure due to perivalvular leakage. He died in spite of re-AVR with translocation method.     

Aspergillus terreus infective endocarditis on a porcine heterograft valve

We present the first reported case of Aspergillus endocarditis occurring on a porcine heterograft prosthesis and discuss the literature regarding both Aspergillus endocarditis and endocarditis on a porcine valve. A 65-year-old man underwent aortic valve replacement with a porcine heterograft. Several weeks later he exhibited signs of infection and then of valve failure. Upon removal, the porcine valve substance was found to be grossly infiltrated and destroyed by the Aspergillus organism. The porcine valve has an excellent reputation of being resistant to infection and relatively easy to sterilize by medical management alone. Several surveys attest to the low incidence of endocarditis. Because of our experience with the destruction caused by Aspergillus, however, and because antimicrobials generally fail to eradicate this organism, we urge prompt operation to remove the heterograft valve involved with infection by this organism. The valve diseased with Aspergillus should be replaced with a mechanical prosthesis. In the aortic position, extra-anatomic replacement should be considered to facilitate eradication of periannular infection postoperatively.     

Haemophilus paraphrophilus endocarditis in a prolapsed mitral valve

A case of Haemophilus paraphrophilus endocarditis successfully treated with ampicillin is described. The patient, a 24-year-old woman, had a prolapsed mitral valve. The organism was initally misidentified as H. parainfluenzae, which it closely resembles. H. paraphrophilus is distinguished by its requirement of 10% CO2 for growth on NaCl-free medium and its inability to ferment xylose.     

Transesophageal echocardiography in mitral prosthesis dysfunction: usefulness and limitations in the evaluation of mitral insufficiency

This study was performed to test the usefulness of transesophageal echocardiography in the diagnosis and assessment of pathological mitral regurgitation in patients with mitral valve prostheses. Doppler color flow imaging by transesophageal echocardiography was compared to the transthoracic echocardiography and angiographic and surgical assessment. We analyzed the influence of the spatial configuration of the jet on the semiquantitative assessment of mitral regurgitation. We studied 71 patients with prostheses in mitral position which were submitted for transesophageal echocardiography examination. 51 of these patients were found to have a pathological prosthetic regurgitation that was confirmed in 21 cases by left ventriculography and in 4 during cardiac surgery. Transesophageal echocardiography Doppler color flow imaging identified a regurgitant jet in 31 patients (60.7%). There was complete agreement with the quantitative assessment of regurgitation by angiography or surgery in 36% of the cases. All patients with prosthetic insufficiency observed by angiography or during cardiac surgery were confirmed by transesophageal echocardiography. Complete agreement in grade of severity by transthoracic echocardiography was found in 84% of cases. There was a difference in grade of severity of mitral regurgitation in only 4 patients. Regurgitant jets were classified by transesophageal echocardiography color Doppler in two groups: free jets and impinging wall jets. 21 cases presented a free jet and 31 excentrically directed impinging wall jet of mitral regurgitation. There was complete agreement with hemodynamic assessment of severity in all patients with regurgitant free jets (11/11). In presence of jet wall there was understimation of mitral regurgitation in 28.5% (4/13).(ABSTRACT TRUNCATED AT 250 WORDS)     

Transesophageal echocardiographic assessment of the contribution of intrinsic tissue thickness to the appearance of a thick mitral valve in patients with mitral valve prolapse

OBJECTIVES: This prospective, blinded transesophageal echocardiographic study was performed to determine the relative contributions of leaflet redundancy and overlap versus intrinsic tissue thickening as mechanisms for the apparent increase in diastolic thickness of the mitral valve. BACKGROUND: Increased diastolic thickness of the mitral valve has been identified as an echocardiographic feature that predicts subsequent adverse sequelae in patients with mitral valve prolapse (MVP). METHODS: Eleven patients with clinical and transthoracic echocardiographic evidence of MVP and 11 age-matched control subjects underwent protocol transesophageal echocardiography to image the mitral valve in two orthogonal planes and to measure its thickness in systole and diastole. RESULTS: Maximal diastolic width of the slack, unloaded anterior leaflet was significantly greater in patients with MVP than in control subjects (mean +/- SD: 0.64 +/- 0.20 cm vs. 0.30 +/- 0.04 cm, p < 0.001). Similarly, diastolic posterior leaflet width was greater in patients with MVP (0.67 +/- 0.39 cm vs. 0.31 +/- 0.06 cm, p < 0.01). In contrast, minimal systolic width of the distended pressure-loaded mitral valve was not significantly different between patients with MVP and control subjects for either the anterior (0.22 +/- 0.05 cm vs. 0.20 +/- 0.04 cm, p = NS) or the posterior (0.25 +/- 0.07 cm vs. 0.24 +/- 0.05 cm, p = NS) leaflets. The percent change in leaflet width from diastole to systole (% delta W), an index of the contribution of dynamic factors (e.g., leaflet redundancy and overlap) to the apparent increase in diastolic leaflet thickness, was significantly greater in patients with MVP than in control subjects for both the anterior (% delta W 62 +/- 13% vs. 34 +/- 16%, p < 0.001) and the posterior (% delta W 54 +/- 19% vs. 22 +/- 21%, p < 0.005) leaflets. CONCLUSIONS: The apparent increase in diastolic mitral leaflet thickness in patients with MVP versus control subjects is largely attributable to dynamic factors such as leaflet redundancy, overlap and deformation. During diastole, when the mitral leaflets are slack and unstressed, the leaflets appear markedly thickened in patients with MVP. In contrast, during systole, when developed intraventricular pressure distends the leaflets, causing them to stretch and balloon into the left atrium, the intrinsic tissue thickness is much less than that measured in diastole. These findings have important implications for the morphologic criteria used to diagnose MVP and the potential pathophysiologic mechanisms for adverse sequelae in this syndrome.     

Diagnostic value of echocardiography in infective endocarditis: a probabilistic approach

PURPOSE: Nitric oxide (NO) relaxes ciliary smooth muscle, and endothelin-1 (ET-1) is reported to regulate ciliary muscle tone. Despite the physiological significance of nitric oxide and ET-1, very few studies have attempted to characterize the mutual modes of action of these mediators in this tissue. Thus, the present experiments were designed to investigate a possible relaxation mechanism of nitric oxide in bovine ciliary muscle that has been contracted by ET-1. METHODS: The effects of sodium nitroprusside (SNP), as a nitric oxide donor, methylene blue, as an inhibitor of guanylate cyclase, and 8-bromo-cyclic GMP on the bovine ciliary muscle contracted with ET-1 were examined. The changes in cyclic GMP level and relaxation, in response to SNP alone or in combination with 3-isobutyl-1-methylxanthine (IBMX) as a nonselective inhibitor of phosphodiesterases, were also determined. RESULTS: Sodium nitroprusside (SNP) produced a concentration-dependent relaxation, which was significantly (p < 0.005) augmented by 10(-5) M 3-isobutyl-1-methylxanthine (IBMX) and significantly (p < 0.005) attenuated by 3 x 10(-5) M methylene blue as an inhibitor of guanylate cyclase. The relaxation in response to SNP was accompanied by an increase in the cyclic 3':5' guanosine monophosphate (cyclic GMP) level, which was again significantly (p < 0.05) augmented by 10(-5) M IBMX and significantly (p < 0.005) attenuated by 3 x 10(-5) M methylene blue. The exogenously applied 8-bromo-cyclic GMP relaxed the ciliary muscle strips during the contraction caused by ET-1. CONCLUSIONS: These results lead us to assume that NO generated from SNP is closely related to cyclic GMP production via the activation of guanylate cyclase and, in turn, causes a relaxation response in the bovine ciliary muscle contracted with ET-1.     

Idiopathic mitral valve prolapse-analysis by real-time two-dimensional echocardiography

Mitral valve prolapse is diagnosed in real-time two-dimensional echocardiograms when there are discrepancies in the coaptation zone of the anterior mitral leaflet and the posterior mitral leaflet. Out of the 100 cases of mitral valve prolapse diagnosed in this way, 65 had prolapsed anterior mitral leaflets, 28 prolapsed posterior mitral leaflets and 7 prolapses of both the anterior and posterior mitral leaflets. In addition to the cases with mitral valve prolapse 23 cases of ruptured chordae tendineae of the mitral valve, including 15 cases which had undergone surgery, were investigated. The frequent site of mitral valve prolapse was the posteromedial commissure in the anterior leaflet and the posteromedial and anterolateral commissures in the posterior leaflet. These sites coincide with those where rupture of the chordae tendineae of the mitral valve was apt to occur. An investigation of the relation between age and mitral valve prolapse showed that the number of cases of prolapsed anterior leaflet did not increase with age, but there was an age-related increase in the number of cases of prolapsed posterior leaflets. It was also found that the degree of the prolapse progressed with age. Many of the cases of ruptured chordae tendineae of the mitral valve were in their forties or fifties, and there appeared to be some relation between the progress of the prolapse and age. Mitral regurgitant murmurs were recorded on phonocardiograms, and the severer the degree, the wider the range of the prolapse. Mitral regurgitation was more likely to occur in cases of prolapsed posterior leaflets than in those with prolapsed anterior leaflets, even if the degree and the range of the prolapse were mild.     

Rupture of asymptomatic mycotic aneurysm after valve replacement in infective endocarditis

Mycotic cerebral aneurysms (MCA) are one of the most serious complications of infective endocarditis. The rupture of MCA in patients under anticoagulant therapy following valve replacement carries high mortality. We encountered this serious complication in a patient who had no neurologic symptoms. A 12-year-old girl was scheduled for mitral valve replacement (MVR) 5 weeks after antibiotic therapy for infective endocarditis caused by Staphylococcus aureus. Before the surgery, she did not have any neurologic symptoms or abnormal findings in CT scanning examination. The surgery to remove her mitral valve with bacterial vegetations and replace it with an artificial valve proceeded smoothly and she appeared to begin an uneventful postoperative recovery. However, she suddenly began to complain of severe headache and became unconscious on the fifth days after MVR. A CT scan showed cerebral herniation due to a major subdural hematoma. A ruptured MCA was detected in the orbito-frontal artery and clipped in an emergency operation. She was transferred to the intensive care unit and given continuous infusion of barbiturate to prevent increase of her intracranial pressure. CT scanning and arteriography 10 days after the MCA clipping, revealed a new subdural hematoma and MCA just proximal to the previous clip. It is important to bear in mind that patients with infective endocarditis can have mycotic cerebral aneurysms without any clinical neurologic symptoms.     

Vegetative bacterial endocarditis on the prolapsing mitral valve. Echocardiographic evaluation

Vegetative endocarditis on the prolapsing mitral valve can be diagnosed with an echocardiogram and the response to therapy can be followed with this technique. A dense mass of fuzzy echoes was noted on the prolapsing posterior leaflet of an echocardiogram from a patient with endocarditis. Three months after the initiation of antibiotic therapy, the mass of echoes had disappeared and was replaced by a dense linear echo, suggesting fibrosis of the part of the mitral valve that had been infected previously. Persistence of the echocardiographic evidence of endocarditis, despite negative blood cultures, may indicate persistence of the risk of peripheral embolization.