Combination of an extremely rare and a common congenital valvular anomalies: Accessory mitral valve chordae from left atrium and bicuspid aortic valve.

Accessory chordae tendineae is an extremely rare anomaly. In this case report, we described a 61-year-old female patient newly diagnosed with the combination of an accessory mitral valve chordae extending from left atrium which is an extremely rare congenital anomaly and a bicuspid aortic valve. In our patient, three-dimensional echocardiography showed incremental value over two-dimensional echocardiography in the assessment of the exact localization and the extend of accessory chordea.

Muscularization of the chordae tendinea of the mitral anterior papillary muscle.

The chordae tendineae, described as fibro-collagenous structures, support the leaflets of the atrioventricular valves of the heart in various ways. The chordae tendineae are composed of collagen and elastic fibers. They connect to the ventricular side of the valve leaflets' free border and hinder the leaflets from swinging back into the atrial cavity during systole. Mitral valve chordae tendineae have been classified using a variety of classification systems. To our knowledge, we report a variant chordae tendinea that has yet to be described in the literature. The variant, present only on the mitral anterior papillary muscle, did not show the characteristic appearance of the chorda tendineae. Muscular fibers were observed extending from a larger than usual mitral anterior papillary muscle, inserting into the rough zone of the anterior leaflet. Several tendinous primary and secondary true leaflet chordae emerge from the apical portion of the anterior papillary muscle, inserting into the anterior leaflet's free edge and rough zone. Contraction of this muscular chorda during systole could disrupt the mechanics of valvular closure and result in possible regurgitation across the mitral valve. Additionally, this structure may be subject to rupture during myocardial infarction, leading to valvular dysfunction. The developmental connection between the chordae and papillary muscles could explain the anomalous muscularization of the chordae tendineae observed in this case.

Incidental TEE finding of aberrant chordae tendineae insertion into the basal septum.

A 65-year-old female with severe mitral regurgitation presenting for mitral valve replacement was found to have a previously undiagnosed aberrant papillary muscle with thickened chordae tendineae inserting into the basal septum during intra-operative TEE. Despite its anatomic location, there was no evidence that the aberrant papillary muscle was contributing to the mitral regurgitation or causing left ventricular outflow tract (LVOT) obstruction. The aberrant papillary muscle was resected during the operation and the patient was separated from cardiopulmonary bypass without complications.

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.

Early detection of myocardial dysfunction in a cat that gradually progressed to endomyocardial form of restrictive cardiomyopathy.

BACKGROUND: Restrictive cardiomyopathy (RCM) is a common myocardial disease in cats, characterized by diastolic dysfunction and atrial enlargement without myocardial hypertrophy. Especially, endomyocardial form of RCM, one of the subtypes in RCM, is characterized by endocardial fibrosis, endocardial scar bridging the interventricular septum and left ventricular (LV) free wall, and deformation and distortion of the LV. However, it is unclear how the myocardial dysfunction and the endocardial scar contribute to the pathophysiology of RCM disease progression. CASE PRESENTATION: A 3 years and 2 months old, intact male, Domestic shorthaired cat was presented for consultation of cardiac murmur. At the first visit (day 0), the notable abnormal finding was echocardiography-derived chordae tendineae-like structure bridging the interventricular septum and the LV free wall, resulting high-speed blood flow in the left ventricle. Electrocardiography, thoracic radiography and noninvasive blood pressure measurements were normal. No left atrial enlargement was observed, and LV inflow velocity showed an abnormal relaxation pattern. Although there was no abnormality in tissue Doppler imaging-derived myocardial velocity, two-dimensional speckle tracking echocardiography (2D-STE) revealed a decrease in the LV longitudinal strain and an increase in endocardial to epicardial ratio of the LV circumferential strain on day 0. On day 468, obvious left atrium enlargement and smoke like echo in the left atrium were observed. The LV inflow velocity was fused, and the tissue Doppler imaging-derived early-diastolic myocardial velocity of the septal mitral annulus decreased. Regarding 2D-STE, LV circumferential strain was further decreased, and right ventricular strain was additionally decreased. Although the general condition was good, we made a clinical diagnosis of endomyocardial RCM based on the above findings. On day 503, the cat showed the radiographic evidence of pulmonary edema and congestive heart failure signs. CONCLUSIONS: Cats with abnormal LV structure and associated myocardial dysfunction like this case needs careful observation. Additionally, 2D-STE indices may be useful for early detection of myocardial dysfunction in feline RCM.

The role of strut chordae in mitral valve competence during annular dilation.

Strut chordae, on their own, are not typically thought to aid mitral valve competence. The aim of this study is to assess whether strut chordae aid mitral valve competence during acute annular dilation. Twelve porcine hearts were dissected and tested using an in vitro simulator, with the mitral annulus tested in either a 'normal' or a dilated configuration. The normal configuration included a diameter of 30 mm, a posterior leaflet 'radius' of 15 mm and a commissural corner 'radius' of 7.5 mm; the dilated annular template instead used dimensions of 50 mm, 25 mm and 12.5 mm, respectively. Each mitral valve underwent ten repeat tests with a target systolic pressure of 100 mmHg. No significant difference in the pressure was detected between the dilated and regular annuli for the mitral valves tested (95 ± 3 mmHg cf. 95 ± 2 mmHg). However, the volume of regurgitation for a dilated annulus was 28 ml greater than for a valve with a normal annulus. Following severing of strut chordae, there was a significant reduction in the systolic pressure withstood before regurgitation by mitral valves with dilated annuli (60 ± 29 mmHg cf. 95 ± 2 mmHg for normal annular dimensions; p < 0.05). In conclusion, strut chordae tendineae may play a role in aiding mitral valve competence during pathophysiology.

Cardiac Valvular Lesions due to Kawasaki Disease: A Japanese Nationwide Survey.

OBJECTIVES: To clarify the characteristics of valvular lesions after Kawasaki disease with a Japanese nationwide survey. STUDY DESIGN: Among 137 026 patients in the nationwide Japanese surveys between 2007 and 2016, 290 (0.2%) with valvular sequelae were investigated by questionnaires. RESULTS: Among the 290 patients with valvular sequelae, mitral regurgitation (MR), tricuspid regurgitation, aortic regurgitation, and pulmonary regurgitation were present 1 month after the development of Kawasaki disease in 183 (63%), 112 (39%), 39 (13%), and 49 (17%) patients, respectively. The numbers of patients with MR during the acute phase and 1 year after developing Kawasaki disease were 208 (72%) and 95 (33%), respectively. MR improved significantly during the late period (P < .0001). Although aortic regurgitation and tricuspid regurgitation also improved significantly (P < .001), pulmonary regurgitation did not change. Ruptured mitral valves chordae tendineae occurred in 6 infants by 6 months of age, within 4 months after the onset of Kawasaki disease. Three patients needed mitral valve plasty, and 1 patient died of acute heart failure. Another 4-month-old girl died of an acute myocardial infarction with MR. In the acute phase, there was a significant difference in the MR severity between the intravenous immunoglobulin-responder group and the intravenous immunoglobulin-resistant group (P < .05). CONCLUSIONS: The inflammation caused by acute Kawasaki disease affects the function of the mitral valves. Most cases of MR improve with the alleviation of inflammation. Severe MR may have decreased with the development of treatment for acute vasculitis. However, ruptured mitral valves chordae tendineae rarely occurs in infants younger than 6 months old, within 4 months after Kawasaki disease.

Wnt/ß-catenin signaling enables developmental transitions during valvulogenesis.

Heart valve development proceeds through coordinated steps by which endocardial cushions (ECs) form thin, elongated and stratified valves. Wnt signaling and its canonical effector ß-catenin are proposed to contribute to endocardial-to-mesenchymal transformation (EMT) through postnatal steps of valvulogenesis. However, genetic redundancy and lethality have made it challenging to define specific roles of the canonical Wnt pathway at different stages of valve formation. We developed a transgenic mouse system that provides spatiotemporal inhibition of Wnt/ß-catenin signaling by chemically inducible overexpression of Dkk1. Unexpectedly, this approach indicates canonical Wnt signaling is required for EMT in the proximal outflow tract (pOFT) but not atrioventricular canal (AVC) cushions. Furthermore, Wnt indirectly promotes pOFT EMT through its earlier activity in neighboring myocardial cells or their progenitors. Subsequently, Wnt/ß-catenin signaling is activated in cushion mesenchymal cells where it supports FGF-driven expansion of ECs and then AVC valve extracellular matrix patterning. Mice lacking Axin2, a negative Wnt regulator, have larger valves, suggesting that accumulating Axin2 in maturing valves represents negative feedback that restrains tissue overgrowth rather than simply reporting Wnt activity. Disruption of these Wnt/ß-catenin signaling roles that enable developmental transitions during valvulogenesis could account for common congenital valve defects.

Ruptured mitral valves chordae tendineae around a convalescent infant with acute Kawasaki disease.

Severe valvulitis owing to acute Kawasaki disease leading to severe mitral regurgitation is a rare event in infants. Further, there is less information about underlying ruptured mitral chordae tendineae causing severe mitral regurgitation. We encountered ruptured mitral chordae tendineae in three female patients after Kawasaki disease. The age at the onset of Kawasaki disease ranged from 3 to 8 months, and detection of ruptured mitral chordae tendineae was from 24 to 90 days. Two patients had acute heart failure, and one was asymptomatic. One patient underwent mitral annuloplasty, and the others responded to medication. These ruptured mitral chordae tendineae occurred after the remission of the initial acute Kawasaki disease, in the early course and the convalescent of acute Kawasaki disease. Further, the recurrent fever was also detected in them. The ruptured mitral chordae tendineae in an infant within 6 months can be detected by systolic heart murmur around the convalescent stage of acute Kawasaki disease, although the prevalence is very low.

Identification of Human Pathological Mitral Chordae Tendineae Using Polarization-sensitive Optical Coherence Tomography.

Defects of the mitral valve complex imply heart malfunction. The chordae tendineae (CTs) are tendinous strands connecting the mitral and tricuspid valve leaflets to the papillary muscles. These CTs are composed of organized, wavy collagen bundles, making them a strongly birefringent material. Disorder of the collagen structure due to different diseases (rheumatic, degenerative) implies the loss or reduction of tissue birefringence able to be characterized with Polarization Sensitive Optical Coherence Tomography (PS-OCT). PS-OCT is used to discriminate healthy from diseased chords, as the latter must be excised and replaced in clinical conventional interventions. PS-OCT allows to quantify birefringence reduction in human CTs affected by degenerative and rheumatic pathologies. This tissue optical property is proposed as a diagnostic marker for the identification of degradation of tendinous chords to guide intraoperative mitral valve surgery.

Effect of glutaraldehyde based cross-linking on the viscoelasticity of mitral valve basal chordae tendineae.

BACKGROUND: Mitral valve failure can require repair or replacement. Replacement bioprosthetic valves are treated with glutaraldehyde prior to implantation. The aim of this study was to determine the changes in mechanical properties following glutaraldehyde fixation of mitral valve chordae. METHODS: To investigate the impact of glutaraldehyde on mitral valve chordae, 24 basal chordae were dissected from four porcine hearts. Anterior and posterior basal (including strut) chordae were used. All 24 chordae were subjected to a sinusoidally varying load (mean level 2N, dynamic amplitude 2N) over a frequency range of 0.5-10 Hz before and after glutaraldehyde treatment. RESULTS: The storage and loss modulus of all chordal types decreased following glutaraldehyde fixation. The storage modulus ranged from: 108 to 119 MPa before fixation and 67.3-87.4 MPa following fixation for basal chordae; 52.3-58.4 MPa before fixation and 47.9-53.5 MPa following fixation for strut chordae. Similarly, the loss modulus ranged from: 5.47 to 6.25 MPa before fixation and 3.63-4.94 MPa following fixation for basal chordae; 2.60-2.97 MPa before fixation and 2.31-2.93 MPa following fixation for strut chordae. CONCLUSION: The viscoelastic properties of mitral valve chordae are affected by glutaraldehyde fixation; in particular, the reduction in storage moduli decreased with an increase in chordal diameter.

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.

The use of artificial chordae in mitral valve repair.

The use of artificial chordae for mitral valve repair has increased and result in excellent long-term results. However, a number of technical challenges remain, and there is an associated learning curve with this technique. We review the current status of artificial chordae for mitral valve repair and discuss the latest innovations for this technique.

The use of a high-power laser on swine mitral valve chordae tendineae.

Worldwide, rheumatic fever remains a significant cause of mitral valve insufficiency. It is responsible for approximately 90 % of early childhood valvular surgeries in Brazil. Elongated or flail chordae are frequently responsible and require surgical correction. The purpose of this study was to analyze and compare the histological tissues of the mitral valve chordae and the mechanical resistance generated by the chordae, both with and without the application of a high-power laser. Twenty normal porcine mitral valve chordae were measured and divided randomly into the following two groups: control group (not subjected to a high-power laser) and laser group (subjected to photonic irradiation). Laser surgery was performed under controlled conditions, using following parameters: λ = 980-nm wavelength, power = 3 W, and energy = 60 J. A mechanical test machine was used in combination with a subsequent histological study to measure chordae tensile properties. A histological analysis demonstrated a typical collagen bundle arrangement in the control group; however, under a particular reached temperature range (48), the collagen bundles assumed different arrangements in the laser group. Significant reductions in the chordae tendineae lengths and changes in their resistance in the laser group were observed, as these chordae exhibited less rigid fibers. The chordae tendineae of normal porcine valves subjected to a high-power laser exhibited its length reduction and less stiffness compared to the control group. A histological analysis of the laser treatment specimens demonstrated differences in collagen bundle spatial organization, following slight changes into tissue temperature.

[New approach in the surgical treatment of mitral regurgitation: beating heart transapical neochord implantation]. / A mitralis elégtelenség sebészi kezelésének új megközelítése: transapicalis ínhúrpótlás dobogó szíven.

Severe mitral regurgitation due to prolapse of the valve demands early surgical intervention. Recently artificial chord implantation is the prefered solution, which requires cardioplegia and application of cardiopulmonary bypass using the left atrial approach. Transoesophageal echocardiography guided transapical neochord implantation is an emerging new technique for the treatment of mitral regurgitation. It enables the operation through left minithoracotomy on beating heart using a special instrument introduced into the left ventricle. Acute procedural success rates in different centres vary between 86 and 100%. According to reports, 92% of the patients do not require additional intervention at the 3-month follow-up. Continuous integration of data resulting improved outcomes supports the hope that this novel, less-invasive technique will be applied widely for the treatment of mitral regurgitation.

Fibrous cyst of the chordae tendineae of the mitral valve: echocardiographic appearance and literature review.

Fibrous cyst of the chordae tendineae of the mitral valve (MV) is defined as a fibrous cyst arising from the chordae tendineae of the MV. It is extremely rare and its etiology is not clear. We present a case of a cystic structure within the left ventricle. This structure is connected to the anterior MV leaflet and the posterior chordae tendineae. It moves freely, resulting in stenosis of inflow tract and outflow tract of the left ventricle. Intraoperative assessment and histopathologic examination revealed it as a fibrous cyst. Its echocardiographic appearance is unique and it must be resected immediately.

Reproducibility in echocardiographic two- and three-dimensional mitral valve assessment.

BACKGROUND: Three-dimensional transesophageal echocardiography (3DTEE) has been demonstrated to provide more accurate information than two-dimensional transesophageal echocardiography (2DTEE) in the localization of mitral valve prolapse (MVP). However, most studies have been single-rater studies. Few results were tested for inter-observer variability with a single second rater. This multicenter study aimed to determine reliability of 2D and 3DTEE mitral valve evaluations by calculating inter-observer agreement between various echocardiographers. METHODS: Fifteen observers from 4 institutions in Germany and Switzerland interpreted 2D and 3DTEE images from 6 patients selected to represent a large spectrum of MVP diversity. Surgical findings served as reference. Individual assessments of MVP and ruptured chordae tendineae (ChR) pathology were compared by calculating Randolph's free-marginal multirater kappa coefficient. RESULTS: Accuracy of MVP evaluation with 3DTEE was 83.9%, CI [81.0%; 86.8%] and 78.7% CI [76.6% 80.8%] with 2DTEE. Flail leaflets with chordal ruptures were described correctly in 91.1%, CI [85.8, 96.4] with 3D compared to 71.1%, CI [65.0, 77.2] with 2DTEE. The multirater kappa coefficient of inter-observer agreement among all 15 observers was κ = 0.65/0.58 for 3D/2D evaluation of MVP and κ = 0.70/0.54 for detection of ChR. CONCLUSION: Three-dimensional assessment of MVP was superior to 2DTEE, although the accuracy of both 3DTEE and 2DTEE was found to be lower than previously published. 3D MVP assessment is less operator dependent than 2DTEE evaluation. Although validity has been demonstrated before, we provide evidence that 3DTEE is reproducible among 15 observers and is a reliable method for MVP evaluation.

Aberrantly inserted chordae tendineae without significant mitral regurgitation.

Aberrantly inserted chordae tendineae in the left atrial side are a rare find. We report here the case of a young patient with aberrantly inserted chordae tendineae not causing significant mitral regurgitation. Because the patient remained asymptomatic and the anomalous chord of the left atrium could be considered within normal human anatomic variation, the authors decided to only monitor the patient's condition for the time being.

Gene expression of Postn and FGF7 in canine chordae tendineae and their effects on flexor tenocyte biology.

Chordae tendineae, referred to as heart tendinous cords, act as tendons connecting the papillary muscles to the valves in the heart. Their role is analogous to tendons in the musculoskeletal system. Despite being exposed to millions of cyclic tensile stretches over a human's lifetime, chordae tendineae rarely suffer from overuse injuries. On the other hand, musculoskeletal tendinopathy is very common and remains challenging in clinical treatment. The objective of this study was to investigate the mechanism behind the remarkable durability and resistance to overuse injuries of chordae tendineae, as well as to explore their effects on flexor tenocyte biology. The messenger RNA expression profiles of chordae tendineae were analyzed using RNA sequencing and verified by quantitative reverse transcription polymerase chain reaction  and immunohistochemistry. Interestingly, we found that periostin (Postn) and fibroblast growth factor 7 (FGF7) were expressed at significantly higher levels in chordae tendineae, compared to flexor tendons. We further treated flexor tenocytes in vitro with periostin and FGF7 to examine their effects on the proliferation, migration, apoptosis, and tendon-related gene expression of flexor tenocytes. The results displayed enhanced cell proliferation ability at an early stage and an antiapoptotic effect on tenocytes, while treated with periostin and/or FGF7 proteins. Furthermore, there was a trend of promoted tenocyte migration capability. These findings indicated that Postn and FGF7 may represent novel cytokines to target flexor tendon healing. Clinical significance: The preliminary discovery leads to a novel idea for treating tendinopathy in the musculoskeletal system using specific molecules identified from chordae tendineae.