首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
OBJECTIVE: To report the successful surgical management (open mitral commissurotomy, OMC) of mitral stenosis (MS), incorporating heart-beating cardiopulmonary bypass (CPB), in a 1-year-old dog. STUDY DESIGN: Clinical case. ANIMALS: One-year-old Cairn Terrier with MS. MATERIALS AND METHODS: Diagnosis of MS was confirmed by means of 2-dimensional, continuous-wave and color-flow Doppler echocardiography. Surgery was performed through a left intercostal thoracotomy. CPB was initiated and the heart was kept beating. The fused commissures of the mitral valve were incised to free the cusps of the valve. RESULTS: Left intercostal thoracotomy allowed easy observation of the mitral orifice during heart-beating OMC. Persistent bleeding from the atriotomy site required a second surgical procedure after which the dog had an uneventful recovery. Echocardiography at 2 weeks and 1 year postoperatively indicated substantial improvement in left ventricular filling (pressure half-time=187 ms before surgery, 105 ms [2 weeks] and 110 ms [1 year] after surgery). Enlargement of the left atrium resolved; however, moderate mitral valve regurgitation was still present. CONCLUSIONS: MS can be successfully treated by OMC, facilitated by use of CPB. Substantial improvement in cardiac function was evident by ultrasound and Doppler examination postoperatively. CLINICAL RELEVANCE: OMC under heart-beating CPB should be considered for the treatment of MS in the dog.  相似文献   

2.
ObjectivesSurgical mitral valve repair is a possible option for dogs with myxomatous mitral valve disease. However, information on surgical results and postoperative echocardiography is limited. This study aimed to verify the stage-specific surgical results of mitral valve repair and postoperative echocardiographic changes for two years following surgery.AnimalsAdult dogs (n = 55) treated with surgical mitral valve repair using the loop-in-loop technique were included in this study. Medical records were retrospectively reviewed.ResultsNinety percent of cases (50/55) survived to discharge, which survival was significantly decreased in myxomatous mitral valve disease advanced-stage dogs, Stage B2 (n = 14): 100%, Stage C (n = 27): 96.2%, and Stage D (n = 14): 71.4%. Significant reductions of overall heart size (vertebral heart score: preoperative 11.4 vs. post one month 10.2, P < 0.001), left atrium (left atrium to aortic root ratio: preoperative 2.3 vs. post one month 1.5, P < 0.001) and left ventricle (left ventricular end-diastolic diameter [normalized for bodyweight]: preoperative 2.2 vs. post one month 1.5, P < 0.001) were documented one month after surgery, showing successful management of mitral regurgitation. All medications for mitral valve disease were discontinued three months after surgery. The recurrence of mitral regurgitation was not evident during the two-year follow-up period.ConclusionsSurgical mitral valve repair with the loop-in-loop technique is associated with significant decreases in indices of cardiac size at one-month post-repair. Disease stage influences operative survival after surgical mitral valve repair.  相似文献   

3.
Mitral valve repair under cardiopulmonary bypass was performed in three dogs with clinical signs associated with mitral regurgitation that were not controlled by medication. Mitral valve repair comprised circumferential annuloplasty and chordal replacement with expanded polytetrafluoroethylene. One dog died 2 years after surgery because of severe mitral regurgitation resulting from partial circumferential suture detachment. The others survived for over 5 years, but mild mitral valve stenosis persisted in one. The replaced chordae did not rupture in any dog. Mitral valve repair appears to be an effective treatment for mitral regurgitation in dogs. Chordal replacement with expanded polytetrafluoroethylene is a feasible technique, demonstrating long‐term durability in dogs. However, mitral annuloplasty techniques need improvement.  相似文献   

4.
OBJECTIVE: To investigate the hemodynamic changes induced by injecting collagenase into the mitral valve to induce mitral valve regurgitation (MVR) in dogs. ANIMALS: 9 healthy Beagles. PROCEDURE: Dogs were randomly assigned to 3 groups: control (saline [0.9% NaCl] solution; n = 3), single collagenase injection (C1; 3), and 2 collagenase injections (C2; 3). Open-heart surgery was performed, and saline or collagenase solutions were injected into the mitral valve. Before and weekly for 11 weeks after surgery, radiography, echocardiography, and phonocardiography were performed. Mean pulmonary arterial pressure and mean pulmonary arterial wedge pressure (mPAWP) were measured before and 11 weeks after surgery. Postmortem examinations were performed after dogs were euthanatized. RESULTS: No changes were detected in the control group during the 11-week follow-up period. A systolic murmur and MVR developed 1 week after surgery in groups C1 and C2. The murmur changed from a protosystolic to a pansystolic murmur, and left atrial diameter and the left atrial-to-aortic root diameter ratio increased with time. Mean pulmonary arterial pressure and mPAWP were greater 11 weeks after surgery in groups C1 and C2, compared with presurgery values. During necropsy, tissue loss was detected in the mitral valve at the site of collagenase injection. Degree of regurgitation corresponded to lesion size. CONCLUSIONS AND CLINICAL RELEVANCE: Injection of collagenase into the mitral valve of healthy dogs induced MVR, and dogs with MVR developed progressive hemodynamic changes without acute overload. Collagenase-induced MVR may be an appropriate model for evaluation of prognostic markers of idiopathic MVR in dogs.  相似文献   

5.
This study evaluated the long-term clinical performance of newly developed porcine bioprosthetic valves cross-linked with glutaraldehyde and polyepoxy compound for mitral valve replacement (MVR) in dogs. Five beagle dogs underwent MVR using the porcine bioprosthetic valves during cardiopulmonary bypass. Antithrombotic drugs were administered only for one month after MVR. Six months after MVR, transvalvular regurgitation was not observed in all dogs, paravalvular leakage was seen only in one dog. Twelve months after MVR, mild transvalvular regurgitations were observed in two dogs. Although diastolic atrioventricular pressure gradient was increased gradually, no significant differences were observed. Pressure half-time and valve area were within normal ranges as the bioprosthetic value. There was no clinical symptom of the thrombosis and the thrombogenesis was not observed in the porcine bioprosthetic valve and the annulus in all dogs for twelve months after MVR. The clinical findings suggest that antithrombogenicity of the valves were maintained, though the duability might not be enough in the long-term period.  相似文献   

6.
OBJECTIVE: To describe surgical techniques for and assess outcome of treatment of mitral regurgitation in dogs. DESIGN: Uncontrolled prospective study. ANIMALS: 18 dogs with naturally occurring mitral regurgitation. PROCEDURE: All dogs weighed > 5 kg (11 lb) and had severe mitral regurgitation, congestive heart failure (CHF), and no serious noncardiac disease. Left ventricular volume indices, left atrial size, and degree of mitral regurgitation were determined echocardiographically before and after surgery. Repair techniques included circumferential annuloplasty, placement of artificial chordae, chordal fenestration and papillary muscle splitting, and edge-to-edge repair. Factors predictive for surgery survival and resolution of CHF were determined. RESULTS: 12 dogs survived surgery. Factors predictive for surgery survival included weight > 10 kg (22 lb) and CHF of less than 6 months' duration. In 9 dogs, CHF resolved for a median period of 1 year (range, 4 months to 3 years) after surgery. One dog had stable CHF at 12 months. One dog died as a result of progressive CHF; another was euthanatized for a noncardiac reason. Left ventricular diastolic volume index was 226.9 +/- 117.7 cm3/m2 before surgery and 134.9 +/- 70.4 cm3/m2 at 6 months after surgery (n = 10). Factors predictive for resolution of CHF included left ventricular diastolic volume index < 250 cm3/m2 and systolic volume index < 70 cm3/m2. CONCLUSION AND CLINICAL RELEVANCE: Mitral valve repair may resolve CHF in dogs with severe mitral regurgitation, particularly in dogs that weigh > 10 kg and are treated within 6 months of the onset of CHF.  相似文献   

7.
Porcine bioprosthetic valves cross-linked with glutaraldehyde and polyepoxy compound were newly developed for mitral valve replacement (MVR) in dogs. Five beagle dogs were performed a left thoracotomy and underwent MVR using the porcine bioprosthetic valves during cardiopulmonary bypass (CPB). A vein catheter inserted into right atrium and a vent catheter inserted into the right ventricle to drain. The hemodynamic conditions of CPB were excellent during surgery. The left atrial pressure was measured before and after MVR; there was no significant difference and it was normal. Thrombosis and the prosthetic valve regurgitation were not observed one week after MVR. Pressure half time (PHT) prolonged significantly (P<0.05) from 31.40 +/- 4.0 msec presurgery to 99.20 +/- 19.4 msec at seven days after MVR, although it indicated the normal range as the bioprosthetic valve. The symptom of the prosthetic valve failure was not observed. This study indicated that the MVR using porcine bioprosthetic valves under CPB might have been effective in dogs as a short-term evaluation.  相似文献   

8.
Degenerative mitral valve disease (MVD), the most common acquired heart disease in small-sized dogs, is characterized by valvular degeneration resulting in systolic mitral valve regurgitation (MR). Worsening of MR leads to several combined complications including cardiac remodeling, increased left ventricular filling pressure, pulmonary arterial hypertension, and myocardial dysfunction. Conventional two-dimensional, M-mode, and Doppler examination plays a critical role in the initial and longitudinal assessment of dogs affected by MVD, providing information on mitral valve anatomy, MR severity, left ventricular (LV) size and function, as well as cardiac and vascular pressures. Several standard echocardiographic variables have been shown to be related to clinical outcome. Some of these markers (e.g., left atrium to aorta ratio, regurgitation fraction, pulmonary arterial pressure) may also help in identifying asymptomatic MVD dogs at higher risk of early decompensation, which remains a major issue in practice. However, both afterload and preload are altered during the disease course. This represents a limitation of conventional techniques to accurately assess myocardial function, as most corresponding variables are load-dependent. Recent ultrasound techniques including tissue Doppler imaging, strain and strain rate imaging, and speckle tracking echocardiography, provide new parameters to assess regional and global myocardial performance (e.g., myocardial velocities and gradients, deformation and rate of deformation, and mechanical synchrony). As illustration, the authors present new data obtained from a population of 91 dogs (74 MVD dogs, 17 age-matched controls) using strain imaging, and showing a significant longitudinal systolic alteration at the latest MVD heart failure stage.  相似文献   

9.
A 10-month-old entire male bull terrier was presented with a history of collapse on exercise. Clinical examination, electrocardiography, radiography and echocardiography all supported a diagnosis of mitral valve dysplasia. There was no evidence of congestive heart failure. Surgical intervention consisted of open resection of the dysplastic mitral valve and its replacement with a bioprosthetic valve. The procedure was performed through a median sternotomy and the dog was placed on to full cardiopulmonary bypass. Total cardiopulmonary bypass time was 70 minutes. A full recovery was made and at the time of writing (17 months postoperatively) the dog is clinically normal requiring no medication.  相似文献   

10.
Twenty-nine dogs, including 13 Great Danes and 5 German Shepherd Dogs and averaging 7.3 months age, were diagnosed clinically and radiographically as having mitral regurgitation. Alterations of the mitral valve complex included enlarged anulus; short thick leaflets, with an occasional cleft; short and stout or long and thin chordae tendineae; upward malposition of atrophic or hypertrophic papillary muscles; insertion of one papillary muscle directly into one or both leaflets; and diffuse endocardial fibrosis, occasionally with jet lesions in te left atrium. Other cardiac anomalies included dysplasia of the tricuspid valve (5 dogs), patent ductus afteriosus (2 dogs), aortic stenosis (2 dogs), and ventricular septal defect (1 dog).  相似文献   

11.
Surgical treatment of mitral stenosis (MS) usually consists of open mitral commissurotomy (MC) or percutaneous balloon MC, which require a cardiopulmonary bypass or transseptal approach, respectively. We describe here the first surgical management of congenital MS in a dog using a less invasive procedure, a surgical closed MC under direct echo guidance. A 5-year-old female Cairn terrier was referred for ascites, weakness, and marked exercise intolerance for 2 months, which was refractory to medical treatment. Diagnosis of severe MS associated with atrial fibrillation (AF) was confirmed by echo-Doppler examination and electrocardiography. Poor response to medical treatment suggested a corrective procedure on the valve was indicated. However, due to the cost and high mortality rate associated with cardiopulmonary bypass, a hybrid MC was recommended. A standard left intercostal thoracotomy was performed and three balloon valvuloplasty catheters of differing diameters were sequentially inserted through the left atrium under direct echo guidance. Transesophageal echocardiography revealed a 62% reduction in the pressure half-time compared to the pre-procedure. Thirteen months after surgery the dog is still doing well with resolution of ascites and a marked improvement of most echo-Doppler variables.  相似文献   

12.
A 3-month-old Shetland sheepdog presented with a loud ejection murmur and exercise intolerance. Echocardiography revealed an accessory mitral valve leaflet, characterised by a valve-like structure separate from the mitral valve seen in the subaortic region of the ventricular septum. The left ventricular outflow tract was partially obstructed with a pressure gradient of 12 mmHg. Accessory mitral valve leaflet resection and mitral valvuloplasty were performed during open-heart surgery. Histology performed on the membrane-like structures were indicative of fibrous connective tissues. Postoperative echocardiography confirmed removal of the valve-like structure with resolution of the left ventricular outflow tract obstruction. The pressure gradient was decreased to 4.6 mmHg. The dog was in good condition and no further treatment was required 5 months after surgery. Both cardiac troponin I and NT-proBNP were markedly decreased. In this dog, surgical resection combined with mitral valve plasty resolved the left ventricular outflow tract obstruction and the clinical signs.  相似文献   

13.
OBJECTIVE: To compare platelet aggregation in healthy dogs and dogs with mitral valve regurgitation (MVR) to determine whether regurgitation had an effect on platelet function. ANIMALS: 32 dogs with MVR and 43 healthy dogs. PROCEDURE: Platelet aggregation was measured with an aggregometer, using adenosine 5'-diphosphate as the aggregating agent, and the maximum aggregation and the enhancement of platelet sensitivity (EPS) values were calculated. RESULTS: Platelet count and maximum aggregation were not significantly different between healthy dogs and dogs with MVR. However, EPS values in dogs with MVR were significantly higher than values in healthy dogs. Platelet count and maximum aggregation were not significantly different between dogs classified as New York Heart Association functional class I or II and dogs classified as functional class III or IV; however, EPS values were significantly higher in dogs classified as functional class III or IV. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that platelet aggregation is decreased in dogs with MVR and that the EPS value may be more sensitive to differences in disease severity than in measurement of maximum aggregation.  相似文献   

14.
Twenty horses with mitral valve insufficiency, but without signs of congestive heart failure, and five horses without signs of heart disease were examined before and after medication with an angiotensin-converting enzyme (ACE) inhibitor. The examination included echocardiography assessment as well as heart catheterization. The echocardiographic examination included B-mode, M-mode, conventional and colour Doppler techniques. For 8 weeks, all horses were treated with Accupro 20 (active substance: Quinapril) at an oral dose rate of 120 mg/horse/day. A follow-up of the horses with mitral valve insufficiency after 8 weeks revealed a statistically significant increase in the stroke volume and the cardiac output as well as a decrease in regurgitation velocity time integral (VTI). The regurgitation blood velocity remained the same. The severity of mitral valve insufficiencies revealed a moderate improvement in five horses, from moderate to mild, after therapy. Significant changes of cardiac dimension (B-mode) and shortening fraction (M-mode) before and after treatment could not be observed. The owners' judgement of the horses' performance was that of a minor improvement. In the horses without clinical findings the results of examination before and after treatment remained the same.  相似文献   

15.
Endocardial splitting and left atrial rupture were diagnosed in a dog with mitral regurgitation that experienced the sudden onset of collapsing episodes, weakness, depression, labored breathing, and weak pulses. Thoracic radiographs showed a rounded cardiac silhouette with prominent left atrium consistent with hemopericardium due to left atrial rupture. Two-dimensional echocardiography confirmed the presence of severe mitral valve disease, pericardial fluid, and a laminated blood clot caudal to the left ventricle. A sterile emergency thoracotomy was performed, the hemopericardium and blood clot were removed, and the rupture site in the left atrium was repaired with reinforced sutures. The dog recovered from surgery but died the next day, presumably from a ventricular arrhythmia.  相似文献   

16.
Traumatic detachment of the mitral valve from the annulus fibrosis occurred in a dog following blunt chest trauma. Euthanasia was elected approximately 7 months posttrauma due to refractory, chronic left heart failure. This is the first reported case of traumatic mitral valve rupture in a dog.  相似文献   

17.
Pimobendan has a dual mechanism of action: it increases myocardial contractility by increasing calcium sensitization to troponin C and it promotes vasodilation by inhibiting PDEIII. This study examined the effects of pimobendan on cardiac function, hemodynamics, and neurohormonal factors in dogs with mild mitral regurgitation (MR). The dogs were given 0.25 mg/kg of pimobendan orally every 12 hr for 4 weeks. With pimobendan, the heart rate and stroke volume did not change, but the systolic blood pressure gradually decreased and the degree of mitral valve regurgitation tended to decrease. Renal blood flow was significantly increased and the glomerular filtration rate was slightly increased at 2 and 4 weeks. Furthermore, over the 4-week period, the plasma norepinephrine concentration decreased significantly, the systolic index increased slightly, the left atrial diameter and the left ventricular diameters decreased significantly, and the heart size improved. Given these results, pimobendan appears to be useful for treating MR in dogs. However, further long-term studies of pimobendan involving a larger number of dogs with mild and moderate MR are needed to establish the safety of pimobendan and document improvements in quality of life.  相似文献   

18.
Previous studies have demonstrated that regurgitant fraction can be measured by using the proximal isovelocity surface area (PISA) method. For this study, we utilized this Doppler echocardiographic method to estimate the magnitude of mitral regurgitation in dogs with myxomatous mitral valve disease. Seventeen older, small dogs with chronic mitral regurgitation and no to mild myocardial failure were studied. A blinded observer judged the clinical severity of mitral regurgitation to be mild, moderate, or severe by using echocardiographic assessment of left heart size. The regurgitant fraction was calculated by using the PISA method and spectral Doppler echocardiography. The regurgitant fraction was compared to the clinical assessment of severity for each dog and to calculations of left atrial size. Five dogs had clinically mild mitral regurgitation. Four of these dogs had a regurgitant fraction between 22 and 41%, whereas 1 had a regurgitant fraction of 73%. The 3 dogs with clinical evidence of moderate mitral regurgitation had a regurgitant fraction of 46-65%. All 9 dogs with clinically severe mitral regurgitation had a regurgitant fraction greater than 75% (78-88%). The regurgitant fraction was statistically different between each group (P < .001). A good but curvilinear relationship was found between left atrial size and regurgitant fraction (r2 = 0.72). In this study, dogs with clinically severe mitral regurgitation consistently had hemodynamically severe regurgitation (regurgitant fraction > 75%), whereas dogs with clinically mild to moderate disease had lesser degrees of regurgitation. Good correlation was found between regurgitant fraction and left atrial size. We conclude that the major determinant of left atrial size and disease severity in dogs with mitrial regurgitation is the degree of mitral regurgitation.  相似文献   

19.
An 8-month-old Hanoverian gelding was presented with a history of cardiac murmurs that were not apparent as a foal nor reported at the time of castration. Major echocardiographic findings included mitral valvular thickening, functional stenosis, and mitral regurgitation of sufficient severity to cause diastolic and systolic cardiac murmurs, left-sided volume overload, and pulmonary hypertension. Due to the hemodynamic severity of the lesion and poor prognosis for future performance and longevity, euthanasia was elected. On gross postmortem examination, there was focal fibrous epicarditis affecting the heart base, and the left atrium was moderately dilated. The mitral valve surface was irregular and contained several nodules along the atrial face of the cusp. Histologically, this lesion was diagnosed as a vascular hamartoma, which is rarely reported in veterinary species and has not been described in heart valves. This benign proliferative lesion, and concurrent valvular dysfunction, was associated with an unusual manifestation of clinically evident disease and should be differentiated from common incidental valvular lesions such as hematocysts.  相似文献   

20.
Three cases of ruptured mitral valve chordae in the horse   总被引：1，自引：0，他引：1  
The paper describes clinical observations in three horses with ruptured mitral valve chordae. Horses with ruptured mitral valve chordae may have a history of sudden onset of acute distress with predominantly respiratory symptoms. On auscultation there will be a widespread pansystolic murmur with an extension of the area of cardiac auscultation. The third heart sound may be very pronounced and unduly prolonged, associated with high volume flow during early ventricular filling in diastole. However, these sounds are not specific for chordal rupture--they are typical of severe mitral regurgitation. The electrocardiogram may show predominantly backward spatial vectors during ventricular depolarisation. The condition gives rise to left ventricular volume overload and pulmonary hypertension would be expected in horses showing signs of cardiovascular disturbance or those recently affected. Care is necessary during post mortem examination to avoid cutting through the mitral valve before a proper assessment has been made of the chordal insertions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号