Echocardiographic diagnosis of left ventricular outflow tract obstruction after mitral valve replacement with subvalvular preservation.

We describe two cases of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus. The first patient deteriorated immediately after insertion of a high-profile bioprosthesis. In the second patient, chronic left ventricular outflow tract obstruction developed after the insertion of a low-profile mechanical prosthesis. The clinical course of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus may differ greatly. Evaluation of the left ventricular outflow tract by perioperative transesophageal echocardiography or epicardial echocardiography is essential in the prevention and treatment of this complication.     

Left Ventricular Outflow Tract Obstruction After Mitral Valve Replacement

We describe a patient with left ventricular outflow tract obstruction after mitral valve replacement preserving the anterior subvalvular apparatus. Postoperative transesophageal echocardiography demonstrated systolic narrowing of the left ventricular outflow tract by a bulging septum and systolic anterior motion of the preserved anterior mitral leaflet. Septal myectomy and transaortic mitral apparatus resection enabled us to relieve the left ventricular outflow tract obstruction. This suggests that septal hypertrophy might be a relative contraindication to the preservation of the anterior mitral subvalvular apparatus in mitral replacement.     

Accessory Mitral Valve Tissue: A Case Report and an Updated Review of Literature

Abstract Accessory mitral valve tissue is an unusual congenital cardiac anomaly and a rare cause responsible for left ventricular outflow tract obstruction. An 18‐year‐old patient was referred to this hospital due to an occasionally noted heart murmur in a medical examination. Echocardiography facilitated the diagnosis of accessory mitral valve tissue. To relieve the left ventricular outflow tract obstruction, an operation including resection of the accessory mitral valve tissue, implantation of artificial chordae tendineae, and mitral valve annuloplasty was performed successfully. Postoperative echocardiography showed a complete relief of the mitral valve leaflets and a wide patent left ventricular outflow tract. However, transient ischemic attack and Horner's syndrome complicated the patient early postoperatively. He was administered with a high dose of aspirin, and he recovered shortly. Surgical removal is mandatory insomuch as a definite diagnosis of accessory mitral valve tissue with left ventricular outflow tract obstruction is established. A prophylactic treatment should be applied to the patients with accessory mitral valve tissue in virtue of their susceptibility to neurological events.     

Expanding the use of total mitral valve preservation in combination with implantation of the CarboMedics heart valve prosthesis.

BACKGROUND: Preservation of the mitral valve and subvalvular apparatus was introduced into the clinic in the early sixties, but for two decades the standard technique for mitral valve replacement included excision of both leaflets and their attached chordae tendineae. Lately, increased emphasis has again been placed on retention of the mitral subvalvular apparatus during valve replacement because of its role on left ventricular function. METHODS: We have preserved the valvular and subvalvular mitral apparatus, when possible, in connection with mitral valve replacement during the last seven years and the present investigation (partly prospective and partly retrospective) was done with the aim of making up the results of our mitral preservation technique. In the period between January 1990 and December 1995, 30% of the patients who underwent mitral valve replacement had complete retention of all mitral tissue. In 1996, the percentage had increased to 50, and during the first seven months of 1997, 70% of the patients had complete retention of all mitral tissue. Since January 1997, we have exclusively used the CarboMedics mitral heart valve prosthesis. A total of 56 patients were identified to have had a CarboMedics heart valve prosthesis implanted. There were 33 men and 23 women with a mean age of 63 years, range 23-77 years. Coronary bypass was a concomitant procedure in 22 patients. In seven patients, both the mitral and aortic valves were replaced. A severely altered valve with thickened and or calcified leaflets, stenotic leaflets, or shortened, retracted and thickened chordae tendineae were not a contraindication for the procedure. Calcified plaques were removed. Adhesion between anterior and posterior leaflets was treated with sharp dissection. Valve and subvalvular tissue were preserved. The leaflets were reefed within the valve-sutures and compressed between the sewing ring and the native annulus when implanting the valve prosthesis. Chordal tension on the ventricle was thereby maintained and the chordae pulled away from the valve effluent. Echocardiography with measurement of ejection-fraction was performed preoperatively during the postoperative course in case of cardiac problems and on a routine basis 1 month after surgery and at various intervals when the patient was seen in the outpatient clinic. Left ventricular outflow tract gradients were measured during the postoperative course in case of cardiac problems and routinely 1 month postsurgically. RESULTS: Five patients died in the postoperative period and one patient had transient neurological symptoms. In none of the patients was death or transient neurological symptoms a consequence of the retention of mitral leaflets with subvalvular apparatus. The remaining 51 patients were all alive at follow-up. Postoperative echocardiography demonstrated a preserved left ventricular function and a left ventricular outflow tract without obstruction. CONCLUSIONS: We find that the described technique in combination with implantation of a CarboMedics heart valve prosthesis is very useful even in patients with a severely altered valve, when preserving the mitral leaflets with subvalvular apparatus during valve replacement. The technique is without procedure related complications and preserves left ventricular function without obstructing the left ventricular outflow tract.     

Accessory mitral valve associated with aortic regurgitation in an elderly patient: report of a case

We encountered a 75-year-old man who complained of exertional dyspnea. An echocardiographic examination showed aortic regurgitation and a tumor in the left ventricular outflow tract. Under complete extracorporeal circulation, we surgically made an incision of the ascending aorta with a slight thickening of the aortic valve and an enlarged annulus. After excising the aortic valve, an examination of the subvalvular region revealed mitral valve-like tissue extending from the annular region of the right coronary cusp to the ventricular septum, while the chordae tendinae was attached to the septum. This issue was excised, and the aortic valve was replaced with a 27-mm SJM valve. The postoperative course was uneventful, and the patient was discharged in good condition on postoperative day 30. An accessory mitral valve is extremely rare. Since this indication for surgical treatment is associated with congenital heart disease or a left ventricular outflow tract obstruction, most patients are young. Our patient had no associated cardiac anomalies and no pressure gradient attributable to a left ventricular outflow tract obstruction. This accessory mitral valve was discovered during aortic valve replacement surgery. To our knowledge, our patient is the oldest reported with an accessory mitral valve to have undergone a surgical resection.     

Accessory mitral tissue - an unusual cause of left ventricular outflow tract obstruction

Accessory mitral valve tissue is one of the rare anomalies of embryonic development of the endocardial cushion. We describe here a case of a 9?year old male who presented with dyspnoea on exertion. Transthoracic and transesophageal echocardiography revealed aneurysm of membranous part of the interventricular septum producing left ventricular outflow obstruction. Left ventriculography showed a filling defect in the area of mitral aortic interventricular fibrosa probably a localized subaortic membrane. But intraopertive findings showed an accessory mitral valve tissue attached to the annulus of anterior leaflet with its chordal attachment to the papillary muscles of normal mitral valve and to the interventricular septum. The anomalous tissue was excised with its attachment through the aortotomy and left atriotomy. We emphasize, that fixed type of left ventricular outflow tract obstruction produced by an accessory mitral tissue can mimic an aneurysm of the interventricular septum on echocardiography and surgical excision through bicameral approach is recommended.     

Hypertrophic cardiomyopathy and caesarean section: intraoperative use of transthoracic echocardiography

A pregnant woman with severe hypertrophic cardiomyopathy was monitored with transthoracic echocardiography to guide management of fluids and vasopressors during elective caesarean section. After insertion of intravenous, arterial and central venous cannulae, a transthoracic echocardiogram was performed noting left ventricular cavity size and contractility, systolic anterior motion of the mitral valve and left ventricular outflow tract obstruction. Following combined spinal-epidural anaesthesia, serial examinations were made intraoperatively. Short-lived haemodynamic instability ensued just before the incision and with administration of oxytocin. Her postoperative course was complicated by post-partum haemorrhage requiring radiological intervention but she ultimately recovered fully. Maintaining preload to avoid worsening of left ventricular outflow tract obstruction is essential in these patients. A transthoracic echocardiogram is easily performed, of low risk and provides more useful information than a pulmonary artery catheter.     

Mitral valve replacement with bileaflet preservation: a modified technique.

We present a modified bileaflet preserving mitral valve replacement technique to eliminate left ventricular outflow tract obstruction and larger size prosthesis implantation. Mitral anterior leaflet was incised from the middle of leaflet to mitral annulus. Pletgetted sutures were firstly bitten from mitral annulus and then passed from the bottom to the tip of anterior leaflet. These sutures were anchored to prosthesis. Bileaflet prosthesis was put down into the annulus and sutures were ligated on the strut of prosthesis. Posterior leaflet was also preserved. Excessive anterior leaflet tissue was attached to left atrium wall by deeply bitten sutures.     

Sudden Development of Intraoperative Left Ventricular Outflow Obstruction: Differential and Mechanism. An Intraoperative Two-Dimensional Echocardiographic Study

Systolic anterior motion (SAM) of the mitral valve, once considered to be pathognomonic of hypertrophic cardiomyopathy, has been reported in the absence of asymmetric septal hypertrophy. Of the 1,000 open heart operations performed with intraoperative two-dimensional epicardial echocardiography monitoring, four patients developed intraoperative dynamic left ventricular outflow obstruction associated with systolic anterior motion of the mitral valve that was not present preoperatively: three cases of mitral valve annuloplasty with Carpentier ring insertion and one of coronary artery bypass grafting. Though no patient had asymmetric septal hypertrophy or echocardiographic evidence of outflow obstruction by either preoperative cardiac catheterization or echocardiography, intraoperative two-dimensional epicardial echocardiography revealed SAM, and hyperdynamic left ventricles with three of these patients having documented left ventricular outflow tract gradients causing hemodynamic compromise. (Case 4 was hemodynamically stable following mitral valve repair, but had SAM and significant residual mitral regurgitation [MR] requiring reinstitution of cardiopulmonary bypass and re-repair). Measurement of mitral annular dimension demonstrated a normal decrease in size from diastole to systole in control operative subjects but not in the patients who developed outflow obstruction. The pathophysiology, treatment, and role of intraoperative echocardiography of dynamic left ventricular outflow tract obstruction are discussed.     

Nonobstructing Accessory Mitral Valve Tissue and Ventricular Septal Defect

A 4-month-old boy with ventricular septal defect was found to have accessory mitral valve tissue attached to the anterior leaflet of the mitral valve. Operation was successfully performed to excise the accessory mitral tissue in the left ventricular outflow tract and close the ventricular septal defect. Most previously reported cases with accessory mitral valve tissue were associated with left ventricular outflow tract obstruction. This boy had no pressure gradient across the left ventricular outflow tract. The indications for prophylactic excision of nonobstructing accessory mitral valve tissue in a patient with other forms of congenital cardiac disease are discussed.     

Obstruction dynamique intraventriculaire gauche après chirurgie réparatrice valvulaire mitrale

A 71 -years-old patient, undergoing mitral valve repair for degenerative valvulopathy and correction of pectus excavatus experienced a cardiogenic shock after weaning from cardiopulmonary bypass. The shock occurred after calcium chloride administration and was unresponsive to inotropic drugs. Transoesophageal echocardiography showed left ventricular outflow tract obstruction due to systolic anterior motion (SAM) of the mitral valve. Discontinuation of inotropic drugs and volume expansion restored the haemodynamic status. By its haemodynamic effects calcium chloride can cause left ventricular outflow tract obstruction, recognized by transoesophageal echocardiography.     

Asymptomatic and isolated accessory mitral valve tissue in an adult

Accessory mitral valve (AMV) tissue is a congenital anomaly that occurs in association with other congenital anomalies, and is an uncommon cause of left ventricular outflow tract obstruction. It is usually detected in early childhood when accompanied by symptoms of obstruction of the left ventricular outflow tract, and is rarely diagnosed in adults. We present a case of a 53-year-old man who was referred to our institution for evaluation of a systolic heart murmur. Echocardiography disclosed a diagnosis of AMV tissue. This case was uncommon because of the lack of severe obstruction of left ventricular outflow, cardiac symptoms, or other cardiac anomalies. We were able to carry out surgical resection of AMV tissue to avert possible progression of aortic insufficiency and the risk of a cerebrovascular embolization. The patient’s postoperative course was uneventful, and postoperative echocardiography showed no residual accessory mitral tissue.     

Left ventricular outflow tract obstruction with mitral mechanical prosthesis.

Left ventricular outflow tract obstruction after mitral valve replacement may occur when the native mitral apparatus is preserved intact. Although it has usually been reported using bioprostheses, we present one case using a low-profile mechanical prosthesis. The reduction of left ventricular dimensions and valvular redundancy contributed to this complication. We obtained definitive relief of left ventricular outflow tract obstruction by transaortic exposure and partial resection of the obstructing tissue with the help of video-assisted cardioscopy.     

Rescue surgical embolectomy for fatal pulmonary embolism in patient with intracranial hemorrhage

Left ventricular outflow obstruction may result from preserving the anterior leaflet after mitral valve replacement. A 79-year-old woman, who had a mitral valve replacement with the native mitral leaflets left intact 16 years before, was admitted to our hospital with severe dyspnea due to heart failure. Echocardiography showed systolic anterior motion of preserved anterior mitral leaflet, and continuous wave Doppler detected severe left ventricular outflow tract jets during systole without mitral chordal rupture. Surgical incising of the anterior mitral leaflet through the aortic root relieved the obstruction without removing the prosthetic mitral valve.     

Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement

Dynamic left ventricular outflow tract obstruction developed in a patient in whom the anterior leaflet was retained at mitral valve replacement. It was caused by systolic anterior movement of the native anterior leaflet. Reduced outflow tract diameter, resulting from both posterior displacement of the septum and anterior displacement of the native anterior leaflet by porcine stents, was likely instrumental in promoting dynamic obstruction.     

Mitral annular reconstruction with anterior leaflet flip-over in concomitant surgery for mitral regurgitation associated with extensive posterior annular calcification and hypertrophic obstructive cardiomyopathy

We describe a case of severely calcified posterior mitral annulus associated with grade IV mitral re-gurgitation in addition to significant hypertrophic obstructive cardiomyopathy. A 70-year-old woman underwent successfully annular reconstruction with anterior mitral leaflet flip-over and mitral valve replacement with a bileaflet mechanical prosthesis combined with left ventricular septal myectomy. This technique can serve not only to cover the debrided posterior annulus, but also to eliminate left ventricular outflow tract obstruction and to keep left ventricular function by virtue of not severing ventricular-annular continuity.     

Use of the Alfieri edge-to-edge technique to eliminate left ventricular outflow tract obstruction caused by mitral systolic anterior motion

A 68-year-old woman with concentric left ventricular hypertrophy, prosthetic valve endocarditis with aortic root abscess, and sepsis had aortic root replacement with an aortic allograft. On weaning from cardiopulmonary bypass, she had hemodynamic instability caused by systolic anterior motion of the mitral valve, which resulted in a left ventricular outflow tract obstruction; the peak pressure gradient across the left ventricular outflow tract was 130 mm Hg, and there was moderately severe (3+) mitral regurgitation. After reinstitution of cardiopulmonary bypass, a central Alfieri edge-to-edge stitch was placed between the anterior and posterior leaflets of the mitral valve. This reduced the gradient across the left ventricular outflow tract to 10 mm Hg and eliminated the mitral regurgitation, which enabled successful separation from cardiopulmonary bypass.     

Systolic anterior motion of the mitral valve despite the sliding leaflet technique for repair of the mitral valve

We report a systolic anterior motion of the anterior mitral leaflet despite employing the sliding leaflet technique for repair of mitral valve regurgitation. A 65-year-old man with chronic, symptomatic mitral regurgitation due to ruptured chordae tendineae underwent mitral valve repair by quadrangular resection of the posterior leaflet and sliding leaflet technique with ring annuloplasty. After weaning from cardiopulmonary bypass, left ventricular outflow obstruction developed and transesophageal echocardiography demonstrated systolic anterior motion of the mitral valve and severe mitral regurgitation. Non-operative treatment resolved the outflow tract obstruction, systolic anterior motion and mitral regurgitation. We conclude that post-repair systolic anterior motion can still occur after the sliding plasty procedure and that medical treatment can successfully resolve systolic anterior motion and outflow tract obstruction in most patients.     

Accessory mitral valve causing left ventricular outflow tract obstruction in an adult

Accessory mitral valve (AMV) is a rare congenital abnormality that, rarely, causes left ventricular outflow tract (LVOT) obstruction in adults. We report the case of a 47-year-old man with deteriorating exertional dizziness. Evaluations revealed that the left ventricular outflow tract obstruction was caused by the accessory mitral valve. The patient underwent a successful operation for removal of the accessory mitral valve.     

Preservation of anterior leaflet chordae with modified miki technique: how to do it

During mitral valve replacement, total chordae preservation is very important for left ventricular functions. But leaving anterior leaflet and chordae may cause serious complications, such as left ventricular outflow tract obstruction and impairment in prosthetic valve functions. In this article, we present the anterior leaflet preservation technique by excising the central portion of the anterior leaflet. The rim of the leaflet tissue containing the marginal chordae was divided in two parts without destroying the chordae, and then the rim of leaflet tissue was sutured to the left atrium. This technique provided optimal chordae tension and improved avoidance of complications due to total chordae preservation, in mitral valve replacement operations.