Artificial chordae for mitral valve repair.

BACKGROUND: Mitral valve repair using expanded polytetrafluoroethylene sutures to replace mitral chordae tendineae is a well-established procedure. However, the incidence of neo-chordae failure causing recurrent mitral regurgitation is not well defined. METHODS: We have reviewed the reported cases of complications after mitral valve repair related to the use of neo-chordae. This study was mainly carried out through PubMed, Medline, and Google Chrome websites. RESULTS: We have identified a total of 26 patients presenting with rupture of polytetrafluoroethylene neo-chordae, mostly being described as isolated cases. Few other cases of recurrent mitral regurgitation with hemolysis were found, where reoperation was not caused by neo-chordal failure but most likely by technical errors. At pathological investigation the findings were substantially similar in all reported cases. The neo-chordae retained their length and pliability, became covered with host tissue and rupture was mainly related to suture size. Mild calcification was observed not interfering with chordal function; chordal infection did never occur. CONCLUSIONS: The use of artificial neo-chordae provides excellent late results with durable mitral valve repair stability. Chordal rupture may occur late postoperatively leading to reoperation because of recurrent mitral regurgitation. Despite its rarity, this potential complication should not be overlooked during follow-up of patients after mitral valve repair using artificial neo-chordae.

Acute aortic regurgitation due to fibrous strand rupture.

A 60-year-old male presented with sudden onset chest pain and pulmonary edema. The investigation confirmed torrential aortic regurgitation of a bicuspid valve. At surgery, a ruptured fibrous strand was identified which had been supporting the left-right cusp commissure with loss of attachment to the aortic wall. This case demonstrates that fibrous strands may be present as a supporting structure of the aortic valve, and rupture can be a rare cause of torrential aortic regurgitation, similar in pathogenesis to how it may be associated with acute severe mitral regurgitation and chordae tendineae rupture.

A percutaneous approach to create tricuspid regurgitation in swine: a model for transcatheter tricuspid valve therapy assessment.

PURPOSE: The purpose of this study was to develop a simple and effective percutaneous approach to create tricuspid regurgitation in swine. METHODS: Eleven pigs (71.68 ± 7.70 kg, 3 male) were involved in this study. A grasping forceps was introduced into the right ventricle through a steerable sheath under fluoroscopic guidance and used to disrupt the tricuspid valve apparatus by avulsing leaflet or chordae tendineae repeatedly. Transthoracic echocardiography and right ventricular angiography were used to evaluate the degree of tricuspid regurgitation created. RESULTS: Ten of the 11 pigs (90.91%) achieved severe tricuspid regurgitation and 1 (9.09%) obtained moderate tricuspid regurgitation immediately after the procedure. Heart rate of the pigs significantly increased immediately after tricuspid regurgitation creation compared to baseline (88.64 ± 23.24 vs. 76.00 ± 15.30 bpm, P = 0.02), but recovered to normal level at one month follow-up (77.09 ± 11.97 bpm, P = 0.85). The right atrium, tricuspid valve annulus, and right ventricle dilated obviously one month after tricuspid regurgitation creation (dimension changes: 3.01 ± 0.35 vs. 3.56 ± 0.40 cm, P = 0.02; 2.92 ± 0.36 vs. 3.37 ± 0.39 cm, P = 0.01; 3.06 ± 0.42 vs. 3.60 ± 0.47 cm, P = 0.03 respectively). Autopsy findings showed that rupture of leaflet and/or chordae tendineae finally led to the tricuspid regurgitation. CONCLUSIONS: Severe tricuspid regurgitation can be created by a simple and effective percutaneous approach with a grasping forceps in swine model and right heart dilation can be observed consistently at one-month follow-up. This model will be valuable in pre-clinical studies for developing new tricuspid valve repair or replacement technique to treat severe tricuspid regurgitation.

Aortic Chordae Tendineae Strands with Significant Aortic Regurgitation.

The aortic chordae tendineae strands are suggested to be embryonic remnants of the cusp formation process. We herein describe a 70-year-old male who was admitted to our hospital for shortness of breath and chest tightness. During echocardiographic examination, severe aortic regurgitation with a ruptured fibrous strand was detected. Moreover, another fibrous strand was found by three-dimensional transesophageal echocardiography (TEE). To our knowledge, this is the first literature review of aortic chordae tendineae strands, including diagnosis, management, and mechanisms of aortic regurgitation due to such informal strands.

Spontaneous chordae tendineae rupture during peripartum.

Acute cardiopulmonary distress in pregnancy always carries exceptionally arduous challenge for physicians. Here we report a patient who sustained spontaneous chordae tendineae rupture complicated with severe mitral regurgitation and acute pulmonary edema during peripartum period. Probable causes of chordae tendineae rupture include mitral valve prolapse, infectious endocarditis, congenital heart disease, rheumatic heart disease, ischemic heart disease, connective tissue diseases, previous mitral valve surgery or pregnancy itself. The pathophysiology of spontaneous chordae tendineae rupture due to pregnancy remains unclear. However, certain physiological stress, including hormone changes related matrix remodeling, increased cardiac output during pregnancy or labor pain may precipitate to this condition. Literature reviews from previously reported cases showed that those who were diagnosed chordae tendineae rupture at very preterm period all had preterm delivery.

Arrhythmic Mitral Valve Prolapse and Sudden Cardiac Death.

BACKGROUND: Mitral valve prolapse (MVP) may present with ventricular arrhythmias and sudden cardiac death (SCD) even in the absence of hemodynamic impairment. The structural basis of ventricular electric instability remains elusive. METHODS AND RESULTS: The cardiac pathology registry of 650 young adults (≤40 years of age) with SCD was reviewed, and cases with MVP as the only cause of SCD were re-examined. Forty-three patients with MVP (26 females; age range, 19-40 years; median, 32 years) were identified (7% of all SCD, 13% of women). Among 12 cases with available ECG, 10 (83%) had inverted T waves on inferior leads, and all had right bundle-branch block ventricular arrhythmias. A bileaflet involvement was found in 70%. Left ventricular fibrosis was detected at histology at the level of papillary muscles in all patients, and inferobasal wall in 88%. Living patients with MVP with (n=30) and without (control subjects; n=14) complex ventricular arrhythmias underwent a study protocol including contrast-enhanced cardiac magnetic resonance. Patients with either right bundle-branch block type or polymorphic complex ventricular arrhythmias (22 females; age range, 28-43 years; median, 41 years), showed a bileaflet involvement in 70% of cases. Left ventricular late enhancement was identified by contrast-enhanced cardiac magnetic resonance in 93% of patients versus 14% of control subjects (P<0.001), with a regional distribution overlapping the histopathology findings in SCD cases. CONCLUSIONS: MVP is an underestimated cause of arrhythmic SCD, mostly in young adult women. Fibrosis of the papillary muscles and inferobasal left ventricular wall, suggesting a myocardial stretch by the prolapsing leaflet, is the structural hallmark and correlates with ventricular arrhythmias origin. Contrast-enhanced cardiac magnetic resonance may help to identify in vivo this concealed substrate for risk stratification.

Papillary fibroelastoma involving chordae of the mitral valve with two aortic valve excrescences.

Among primary cardiac tumors, papillary fibroelastoma (PF) represents less than 10% of all such lesions. Of these tumors, 90% are solitary and multiple tumors have rarely been reported. More than 75% of PFs are attached to heart valves, while tumors that originate in the non-valvular endocardium are rare. We report a case of PF originating from the chordae of the mitral valve with two concomitant aortic valve Lambl's excrescences.

Idiopathic mitral valve chordae rupture in an infant: importance of rapid diagnosis and surgery.

Mitral valve chordae rupture in infancy is a rare, but life-threatening disease. The progression of acute cardiac failure has been reported, with emergency surgery being required in most cases. Mitral valve chordae rupture typically occurs at the age of 4-6 months. Echocardiography is needed to diagnose this disease, and accurate diagnosis is difficult for general pediatricians. We herein describe the case of an acutely ill 4-month-old infant, who was saved and discharged without neurological sequelae due to the early diagnosis of mitral valve chordae rupture, life support, and surgery. We confirm the importance of acute pre-surgery treatment and immediate surgery for the survival and good outcome of infants.

Quantitative analysis of mitral valve morphology in mitral valve prolapse with real-time 3-dimensional echocardiography: importance of annular saddle shape in the pathogenesis of mitral regurgitation.

BACKGROUND: Few data exist on the relation of the 3-dimensional morphology of mitral valve and degree of mitral regurgitation (MR) in mitral valve prolapse. METHODS AND RESULTS: Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 112 subjects, including 36 patients with mitral valve prolapse and significant MR (≥3+; MR+ group), 32 patients with mitral valve prolapse but no or mild MR (≤2+; MR- group), 12 patients with significant MR resulting from nonprolapse pathologies (nonprolapse group), and 32 control subjects. The 3-dimensional geometry of mitral valve apparatus was measured with dedicated quantification software. Compared with the normal and MR- groups, the MR+ group had more dilated mitral annulus (P<0.0001), a reduced annular height to commissural width ratio (AHCWR) (P<0.0001) indicating flattening of annular saddle shape, redundant leaflet surfaces (P<0.0001), greater leaflet billow volume (P<0.0001) and billow height (P<0.0001), longer lengths from papillary muscles to coaptation (P<0.0001), and more frequent chordal rupture (P<0.0001). Prevalence of chordal rupture increased progressively with annulus flattening (7% versus 24% versus 42% for AHCWR >20%, 15%-20%, and <15%, respectively; P=0.004). Leaflet billow volume increased exponentially with decreasing AHCWR in patients without chordal rupture (r(2)=0.66, P<0.0001). MR severity correlated strongly with leaflet billow volume (r(2)=0.74, P<0.0001) and inversely with AHCWR (r(2)=0.44, P<0.0001). In contrast, annulus dilatation but not flattening occurred in nonprolapse MR patients. An AHCWR <15% (odds ratio=7.1; P=0.0004) was strongly associated with significant MR in mitral valve prolapse. CONCLUSION: Flattening of the annular saddle shape is associated with progressive leaflet billowing and increased frequencies of chordal rupture and may be important in the pathogenesis of MR in mitral valve prolapse.

Effect of leaflet-to-chordae contact interaction on computational mitral valve evaluation.

BACKGROUND: Computational simulation using numerical analysis methods can help to assess the complex biomechanical and functional characteristics of the mitral valve (MV) apparatus. It is important to correctly determine physical contact interaction between the MV apparatus components during computational MV evaluation. We hypothesize that leaflet-to-chordae contact interaction plays an important role in computational MV evaluation, specifically in quantitating the degree of leaflet coaptation directly related to the severity of mitral regurgitation (MR). In this study, we have performed dynamic finite element simulations of MV function with and without leaflet-to-chordae contact interaction, and determined the effect of leaflet-to-chordae contact interaction on the computational MV evaluation. METHODS: Computational virtual MV models were created using the MV geometric data in a patient with normal MV without MR and another with pathologic MV with MR obtained from 3D echocardiography. Computational MV simulation with full contact interaction was specified to incorporate entire physically available contact interactions between the leaflets and chordae tendineae. Computational MV simulation without leaflet-to-chordae contact interaction was specified by defining the anterior and posterior leaflets as the only contact inclusion. RESULTS: Without leaflet-to-chordae contact interaction, the computational MV simulations demonstrated physically unrealistic contact interactions between the leaflets and chordae. With leaflet-to-chordae contact interaction, the anterior marginal chordae retained the proper contact with the posterior leaflet during the entire systole. The size of the non-contact region in the simulation with leaflet-to-chordae contact interaction was much larger than for the simulation with only leaflet-to-leaflet contact. CONCLUSIONS: We have successfully demonstrated the effect of leaflet-to-chordae contact interaction on determining leaflet coaptation in computational dynamic MV evaluation. We found that physically realistic contact interactions between the leaflets and chordae should be considered to accurately quantitate leaflet coaptation for MV simulation. Computational evaluation of MV function that allows precise quantitation of leaflet coaptation has great potential to better quantitate the severity of MR.

Isolated non-obstructive accessory mitral valve tissue in an adult mimicking ruptured chordae.

Accessory mitral valve tissue is commonly associated with other congenital heart diseases and is usually detected in children causing left ventricular outflow tract obstruction. We present an adult patient with isolated non-obstructive accessory mitral valve tissue that was mimicking ruptured chordae of the mitral valve. Accessory mitral valve tissue in adults is very rare and can mimick various causes of left ventricular outflow tract obstruction. This patient represents the first case in literature wherein an unobstructive accessory mitral valve tissue simulated a ruptured chordae. This case illustrates that in patients with suspected mitral valve chordae rupture without any mitral regurgitation, this diagnosis should be considered, which can have therapeutic implications.

Animal models of mitral regurgitation induced by mitral valve chordae tendineae rupture.

BACKGROUND AND AIM OF THE STUDY: Mitral regurgitation (MR) is a common valvular disease throughout the world. Various diagnostic techniques have been developed to assess the causes and severity of MR, and the therapeutic approaches to this disease have been widely documented. However, treatments for chronic MR remain controversial, and various animal models of chronic MR (including chordae tendineae rupture, rapid pacing and ischemia) have been developed to study the pathophysiology and therapeutic approaches to this condition. The study aim was to review the animal MR models that have been developed using a mitral valve chordae tendineae rupture technique. METHODS AND RESULTS: Among the animals used for these investigations, dogs and sheep have been most commonly used as models of MR induced by mitral valve chordae tendineae rupture, mainly due to considerations of cardiac size. Chordae tendineae cutting is performed using either closed- or open-chest techniques. In the closed-chest model, long flexible grasping forceps are positioned percutaneously in order to tear the mitral valve chordae. In the open-chest model, cardiopulmonary bypass is performed, and either selected chordae are cut under direct visualization or a non-specified number of chordae are cut, using a metal device inserted through the left ventricular apex. Whichever model is used, MR has been found to become chronic at three to six months after the induction of MR by chordae rupture. The reported mortality and complication rates of these models are high. CONCLUSION: In the long term, the experimental evolution of chronic MR is similar to the evolution occurring naturally in patients suffering from the condition. Hence, these models could be useful in understanding the disease better, and in testing new therapeutic modalities. The present review summarizes the physiological effects of each of these techniques, and compares the advantages and disadvantages of each procedure.

Recurrent mitral regurgitation due to ruptured artificial chordae: case report and review of the literature.

The use of expanded polytetrafluoroethylene (ePTFE) sutures has become an established method to correct mitral regurgitation due to elongated or ruptured mitral chordae. Mitral valve repair using artificial chordae has demonstrated excellent long-term results, particularly as ePTFE retains its flexibility with time and is highly resistant to mechanical stress. On conducting a literature review, four cases were found of recurrent mitral regurgitation due to the late (6-14 years postoperatively) rupture of ePTFE chordae. Herein, the case is described of artificial chordal rupture that required reoperation at 11 years after the initial mitral valve repair. In all previously reported cases, chordal rupture was related to the calcification of ePTFE, whereas in the present case only minimal calcification was observed at histology, and chordal rupture was most likely due to ePTFE fatigue-induced lesion. Although rare, rupture of the artificial chordae may cause recurrent mitral regurgitation; hence, the continuous monitoring of these patients, especially when the follow up extends beyond 10 years, appears mandatory.

Clinical characteristics of acute mitral regurgitation due to ruptured chordae tendineae in infancy-experience at a single institution.

In infants, acute mitral regurgitation resulting from ruptured chordae tendineae is very rare, but often fatal. There are a few case reports, but the characteristics and etiology of chordae tendineae rupture have not been elucidated. Our aim was to determine the clinical characteristics of idiopathic acute mitral regurgitation due to chordal rupture in infancy. A retrospective analysis was performed on ten consecutive patients, with a mean onset age of 4.6 ± 1.3 months. Despite nonspecific initial symptoms, all patients developed respiratory distress and four required resuscitation within a few days (mean, 1.8 ± 1.8 days). Chest radiographs showed pulmonary congestion with a normal or mildly increased cardiothoracic ratio in all ten patients. Laboratory data and electrocardiograms showed nonspecific findings. Echocardiography revealed ruptured chordae in all patients; locations were anterior (50%), posterior (20%), and both (30%). Surgical intervention was performed within 24 h of admission in eight patients (mean, 3.6 ± 5.1 h). Pathological findings included inflammatory cells in six specimens and myxomatous degeneration in two. No bacteria were isolated from preoperative blood cultures, pathological tissues, or excised tissue cultures. Autoantibody levels were insignificant. Three preoperatively resuscitated patients developed neurological sequelae and arrhythmias occurred in four after mitral valve replacement. Acute onset and rapid deterioration in patients with ruptured chordae tendineae necessitates early surgical intervention to improve outcomes. Though the etiology remains unknown, onset is in infants approximately 4 months of age, suggesting a definite disease entity.

Morphology of the papillary muscles and the chordae tendineae of the ventricles of adult human hearts.

INTRODUCTION: The papillary muscles (PM) play a vital role in atrioventricular (AV) valve function. The PM and their chordae tendineae (CT) regulate the closure of the AV valve during systole. The present study was undertaken to categorize the PM based on their shapes and variant patterns and CT based on their types and the branching pattern. METHODS: This study included formalin-fixed ten adult cadaveric heart specimens. We observed the number, shape, length, breadth, pattern, and presence of extra PM. The number of chordae attached to the tip of each PM was quantified. We classified the types and branching patterns of the chordae and their pattern of attachment to the cusps. RESULTS: In the right ventricle, conical, truncated, and flat-topped PM were observed. The anterior PM had 5.3 ± 1.9, the posterior PM had 2.7 ± 2.1, and the septal PM had 3.5 ± 2.3 CT attached to it. In the left ventricle, we observed conical, truncated, flat-topped, bifurcate, and trifurcate shapes of PM. The anterior and the posterior PM had 7.7 ± 2.8 and 7.7 ± 2.7 CT attached to them, respectively. The true CT were cusp, cleft, and commissural and the false CT were pillar-wall, inter-pillar, and strut. We also found 3 branching patterns for the chordae (single, fan-shaped, and web forming). CONCLUSION: The study explored the comparative morphology of PM and chordae in the right and left ventricles. The knowledge of the morphological pattern of PM and CT would contribute to the valvular function and aid in diagnosing conditions such as valve prolapse or regurgitation.

Right atrioventricular valve dysplasia in a meerkat.

A 7-y-old, captive, intact female meerkat (Suricata suricatta) was presented with lethargy, decreased appetite, dyspnea, and distended abdomen. At autopsy, the right atrium was markedly dilated, and the right atrioventricular valve (RAV) was dysplastic with shortened or absent chordae tendineae and direct attachment of the valve to the papillary muscles, which, in turn, were fused and abnormally positioned. The right ventricle was considered to be hypertrophied. Also present were hydrothorax, ascites, atelectasis, and hepatic congestion. A diagnosis of RAV dysplasia was made. Histologic findings included hypertrophy of cardiomyocytes and marked centrilobular hepatic congestion and hemorrhage, which were consistent with right-sided heart failure.

Shannon entropy as a reliable score to diagnose human fibroelastic degenerative mitral chords: A micro-ct ex-vivo study.

This paper is aimed at identifying by means of micro-CT the microstructural differences between normal and degenerative mitral marginal chordae tendineae. The control group is composed of 21 normal chords excised from 14 normal mitral valves from heart transplant recipients. The experimental group comprises 22 degenerative fibroelastic chords obtained at surgery from 11 pathological valves after mitral repair or replacement. In the control group the superficial endothelial cells and spongiosa layer remained intact, covering the wavy core collagen. In contrast, in the experimental group the collagen fibers were arranged as straightened thick bundles in a parallel configuration. 100 cross-sections were examined by micro-CT from each chord. Each image was randomized through the K-means machine learning algorithm and then, the global and local Shannon entropies were obtained. The optimum number of clusters, K, was estimated to maximize the differences between normal and degenerative chords in global and local Shannon entropy; the p-value after a nested ANOVA test was chosen as the parameter to be minimized. Optimum results were obtained with global Shannon entropy and 2≤K≤7, providing p < 0.01; for K=3, p = 2.86·10-3. These findings open the door to novel perioperative diagnostic methods in order to avoid or reduce postoperative mitral valve regurgitation recurrences.

Acute Mitral Regurgitation Due to Chordae Tendineae Rupture: A Rare Presentation of Cardiac Amyloidosis.

BACKGROUND In cardiac amyloidosis (CA), misfolded proteins deposit in the extracellular space of cardiac tissue. These deposits classically cause restrictive cardiomyopathy with diastolic dysfunction. Although there are at least 30 proteins known to cause amyloid aggregates, 2 main types make up most diagnosed cases: light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Since CA is considered a rare condition, it is often underdiagnosed or recognized in the advanced stages. Once amyloid deposits involve the heart tissue, they are associated with a worse outcome and higher mortality rates, especially in patients presenting symptoms of heart failure. CASE REPORT We report a case of a 22-year-old man presenting with acute severe mitral regurgitation, secondary to posterior mitral leaflet chordae tendineae rupture (CTR). Surgical mitral valve replacement with a mechanical prosthesis was performed, and cardiac tissue biopsy samples were obtained. After surgery, the patient improved significantly but suddenly presented with hemodynamic deterioration, until he died due to severe hemodynamic compromise and multiorgan failure. Although the etiology of the CTR was not established before surgical intervention, the histopathological analysis suggested CA. CONCLUSIONS CA diagnosis can be complex, especially in a 22-year-old-man with atypical clinical and imaging manifestations. In this patient, other differential diagnoses were considered, since CA presenting in a young patient is a rare phenomenon and acute mitral regurgitation secondary to CTR presents more frequently in other heart conditions. Furthermore, rapid postoperative deterioration resulted in the patient's death before biopsy samples were available because suspicion of amyloidosis had not been raised until that point.

Papillary muscle rupture: an unusual complication of chordal sparing mitral valve replacement.

An adult patient with advanced rheumatic heart disease undergoing chordal sparing mitral valve replacement as well as aortic valve replacement is presented. The patient developed an unusual complication of an infarction of the retained head of the anterolateral papillary muscle with subsequent spontaneous rupture 72-hours postoperatively. The ruptured head of the papillary muscle was successfully resected via an aortotomy through the aortic valve prosthesis. The patient made an uneventful recovery. Care to avoid excessive tension on the preserved chordae during mitral valve replacement, especially in the setting of chronic rheumatic carditis, is stressed.