Papillary Muscle Research Articles

Three-Dimensional Finger Test: A New Echocardiographic Method to Locate the Best Access Site During NeoChord Procedure.

Transventricular beating-heart mitral valve repair (TBMVR) with artificial chordae implantation is a technique to treat mitral valve prolapse. Two-dimensional (2D) echocardiography completed with simultaneous biplane view during surgeon finger pushing on the left ventricular (LV) wall (finger test [FT]) is currently used to localize the desired LV access, on the inferior-lateral wall, between the papillary muscles (PMs). We aimed to compare a new three-dimensional (3D) method with conventional FT in terms of safety and better localization of LV access. During TBMVR, conventional FT was completed using 3D transesophageal echocardiography by placing the sample box in the bicommissural view of the LV, including the PMs and the apex. The 3D volume was subsequently edited to visualize the LV from above (surgical view) to localize the bulge of the operator's finger pushing on the LV. We asked the first operator, the second operator, and the cardiac surgery fellow, separately, to evaluate the location of their finger pushing, both with the 2D method and the 3D method, to estimate the interoperator concordance. From 2019 to 2021, 42 TBMVRs were performed without complications related to access using FT completed with the 3D method. Regarding the choice of the right and safe entry site, the operator's agreement was higher using 3D rendering compared with conventional FT (mean agreement 0.59 ± 0.29 for 2D vs 0.83 ± 0.20 for 3D), while full operator agreement was 10 of 42 for 2D and 23 of 42 for 3D (P = 0.004). Three-dimensional FT is easy to perform and facilitates surgeons choosing the best access for TBMVR in term of anatomical localization and safety.

Morphology features of the endocardial structures of the right ventricle of the Siberian roe deer heart

Hemodynamics of blood through the heart is carried out in one direction, where the diastole of the heart is replaced by a systole, and promotes the movement of blood through the circulatory circles. An important role in this is played not only by the heart valves, which restrain the movement of blood into the atria (sash) and ventricles (aortic valve and pulmonary artery), but also by myoendocardial formations and respiratory motility organs. In the available literature, the specific features of the heart in different animal species have been determined, however, no descriptions of the anatomy of endocardial formations of the right ventricle of the heart have been found in males of the Siberian roe deer.To assess the morphometric structures, hearts from 18-month-old Siberian roe deer males (n=3) obtained on the territory of the hunting grounds of the Irkutsk region were used. The heart has an ellipsoid shape, where the right ventricle is located above the level of the rounded tip of the left ventricle. Its internal structure is characterized by pronounced trabeculation, where two folding trabeculae are defined from the side of the free wall, which prevent the overgrowth of the fibrous ring. Among the relief of the right ventricle of the heart of the Siberian roe deer, four papillary muscles are distinguished – large, small, subterranean and additional, with certain morphological forms and indicators.Muscles give up to 24-27 tendon strings to the valve flaps. The septomarginal trabecula connects the base of the large papillary muscle and the interventricular septum, and three to four tendon cords between the septum and the ventricular wall.The greatest value of the height of the tricuspid valve flap was noted at the wall, and the width of the fastening and thickness at the partition flaps. The presence of two or three intermediate flaps was noted, which differ in smaller sizes (height - 9.5 ± 0.71; width – 10.2 ± 0.21 and thickness – 0.19 ± 0.01 mm).

Phosphorylation Mimetic of Myosin Regulatory Light Chain Mitigates Cardiomyopathy-Induced Myofilament Impairment in Mouse Models of RCM and DCM.

This study focuses on mimicking constitutive phosphorylation in the N-terminus of the myosin regulatory light chain (S15D-RLC) as a rescue strategy for mutation-induced cardiac dysfunction in transgenic (Tg) models of restrictive (RCM) and dilated (DCM) cardiomyopathy caused by mutations in essential (ELC, MYL3 gene) or regulatory (RLC, MYL2 gene) light chains of myosin. Phosphomimetic S15D-RLC was reconstituted in left ventricular papillary muscle (LVPM) fibers from two mouse models of cardiomyopathy, RCM-E143K ELC and DCM-D94A RLC, along with their corresponding Tg-ELC and Tg-RLC wild-type (WT) mice. The beneficial effects of S15D-RLC in rescuing cardiac function were manifested by the S15D-RLC-induced destabilization of the super-relaxed (SRX) state that was observed in both models of cardiomyopathy. S15D-RLC promoted a shift from the SRX state to the disordered relaxed (DRX) state, increasing the number of heads readily available to interact with actin and produce force. Additionally, S15D-RLC reconstituted with fibers demonstrated significantly higher maximal isometric force per cross-section of muscle compared with reconstitution with WT-RLC protein. The effects of the phosphomimetic S15D-RLC were compared with those observed for Omecamtiv Mecarbil (OM), a myosin activator shown to bind to the catalytic site of cardiac myosin and increase myocardial contractility. A similar SRX↔DRX equilibrium shift was observed in OM-treated fibers as in S15D-RLC-reconstituted preparations. Additionally, treatment with OM resulted in significantly higher maximal pCa 4 force per cross-section of muscle fibers in both cardiomyopathy models. Our results suggest that both treatments with S15D-RLC and OM may improve the function of myosin motors and cardiac muscle contraction in RCM-ELC and DCM-RLC mice.

Mitral homograft in tricuspid position: indications for implantation and surgical technique

HighlightsThe article presents the latest data on the techniques of implantation of the mitral homograft in the tricuspid position, and identifies groups of patients who are best suited for this method. Moreover, the article describes the evolution of this type of replacement, and highlights that many surgical techniques, although justified, require further study to show demonstrate their advantages. AbstractDespite the general trend in cardiac surgery towards valve-preserving interventions, valve replacements remain relevant, and the search for the perfect prosthetic valve continues. Many believe that tricuspid valve replacement using a mitral homograft can be the method of choice in certain situations. The analysis of the studies found in the PubMed database led the authors to the following conclusions: most of the data on the use of this technique in patients with infective endocarditis (IE), other indications are congenital heart disease (CHD) and rheumatic heart disease. Patients with IE who have undergone tricuspid valve replacement using a mitral homograft have good medium-term prospects, and respond well to medical treatment of recurrent IE. The mitral homograft in the tricuspid position remains intact even after prosthetic endocarditis. In this regard, it is possible to perform reconstructive intervention in case of prosthetic valve dysfunction without the need for repeated replacement. Such interventions are relevant for patients with growing heart for whom annuloplasty at the first stage of surgery is undesirable. Moreover, it is also cost-effective due to the high cost and low availability of homografts. The possibility of repeated tricuspid valve-in-valve replacement is important for patients who may not survive open surgery. To date, there are not enough long-term and short-term data on using a mitral homograft for tricuspid valve replacement, however, it can be assumed that the results of this technique will be positive provided that the appropriate implantation technique and strict patient selection are ensured. Many authors have come to the conclusion that the optimal homograft implantation technique includes sewing of the graft`s papillary muscles into the wall of the myocardium of the right ventricle (RV), fixating them on the outer surface of the RV, anatomical positioning of the homograft (anterior leaflet faces towards the IVS), and the use of an annuloplasty ring.

Some features of the morphology of the heart (nasua nasua)

Nasua nasua is a representative of the forests of South America, and is also kept as a zoo animal. The animals have a pronounced mobile and long nose, a fluffy long tail, as a means of signaling; strong claws on the pectoral limbs, which serve not only to move through trees, but also to get food. Currently, there are isolated works on the morphology of the abdominal aorta of this type, but no features of the morphology of the heart have been found, which was the purpose of our study. The material was preserved in a 10% formalin solution of the heart, taken in different years from sexually mature noses received from the Irkutsk Zoo Gallery and the Siberian Zoo of Irkutsk. Classical methods of morphological research were used in the work: fine dissection, morphometry of the heart and its structures, description, sketches and photographing. According to the results of the studies, it was found that the average value of the absolute mass of the heart was 18.2 ± 0.33 g, has an ellipsoid shape, and the ratio of the thickness of the ventricles is at the level of 1:2.8. The internal structure of the right atrium is built of five scallop muscles of the 1st order and nine of the 2nd order, and four scallop muscles of the 1st order and eight of the second order participate in the relief of the left atrium. The shape of the auricle at the right atrium of the heart is 1.5 times greater than the value of the left atrium. In the left ventricle of the heart there are three papillary muscles (cranial and two caudal) with 21-24 tendon strings, and in the right ventricle there are six papillary muscles that carry up to 31 tendon strings on their surface. The septomarginal trabecula connects the parietal pedicle of the accessory and the base of the large papillary muscle.

Dark papillary muscles sign: a novel prognostic marker for cardiac magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: None. Background the prognostic role of left ventricular (LV) papillary muscle abnormalities in patients with preserved LV systolic ejection fraction (LVEF) is unknown. Aim to evaluate the prevalence and the clinical and prognostic impact of papillary muscle abnormalities by CMR in patients with ventricular arrhythmias, preserved LVEF with no cardiac disease. Methods 391 patients with >500/24h premature ventricular complexes and/or with non-sustained ventricular tachycardia (NSVT), preserved LVEF and no cardiac disease, were enrolled. Different features of LV papillary muscles were considered: supernumerary muscles, papillary thickness, the attachment, late gadolinium enhancement (LGE). The end-systolic hypointensity was defined when its measured signal intensity (SI) was lower than the SI of the septum in early post-contrast cine CMR images. Dark-Paps was defined when both the main papillary muscles had systolic hypointensity. Mitral valve prolapse, mitral annular disjunction (MAD), myocardial LGE were considered. The outcome of hard cardiac events was define as a composite of cardiac death, resuscitated cardiac arrest, and appropriate implantable cardioverter defibrillator (ICD) shock, sustained ventricular tachycardia (lasting ≥30 s at ≥100 beats/min). Results Dark-Paps was found in 79 (20%) patients and was more frequent in females. It was associated with higher prevalence of mitral valve prolapse and MAD. During a median follow-up of 2534 days, 22 hard cardiac events occurred. At Kaplan-Meier curve (Figure) analysis patients with Dark-Paps were at higher risk of events than those without (p<0.0001). Dark-Paps was significantly associated with hard cardiac events in all the multivariate models performed. Dark-Paps improved prognostic estimation when added to NSVT (p = 0.0006), to LGE (p = 0.005) and to a model including NSVT+LGE (p = 0.014). Dark-Paps allowed a significant net reclassification when added to NSVT (NRI 0.30, p =0.03), to LGE (NRI 0.25, p =0.04), and to NSVT + LGE (NRI 0.32, p =0.02). Conclusions Dark-Paps sign could be considered a novel imaging prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction.

Papillary muscle approximation in chronic ovine functional tricuspid regurgitation

ObjectiveIsolated tricuspid ring annuloplasty remains the surgical standard for functional tricuspid regurgitation repair but offers suboptimal results when right ventricular dilation and remodeling along with papillary muscle displacement is present. Addressing subvalvular remodeling with papillary muscle approximation may improve clinical outcomes. MethodsFunctional tricuspid regurgitation and biventricular dysfunction were induced in 8 healthy sheep by rapid ventricular pacing (200-240 bpm) for 27 ± 6 days. Subsequently, animals underwent cardiopulmonary bypass for implantation of sonomicrometry crystals on the tricuspid annulus, right ventricle, and papillary muscle tips. Papillary approximation sutures were anchored between anterior-posterior and anterior-septal papillary muscles and externalized through right ventricular free wall to epicardial tourniquets. After weaning from cardiopulmonary bypass, sequential papillary muscle approximations were performed. Simultaneous hemodynamic, sonomicrometry, and echocardiographic data were collected at baseline and after each papillary muscle approximation. ResultsWith rapid pacing, right ventricular fractional area change decreased from 59 ± 6% to 38 ± 8% (P < .001), whereas tricuspid annulus diameter increased from 2.4 ± 0.3 cm to 3.3 ± 0.6 cm (P = .003). Tricuspid regurgitation (0-4+) increased from +0 ± 0 to +3.3 ± 0.7 (P < .001). Both anterior–posterior and anterior–septal papillary muscle approximation significantly reduced functional tricuspid regurgitation from +3.3 ± 0.7 to +2 ± 0.5 and +1.9 ± 0.6, respectively (P < .001). Reduction of tricuspid insufficiency with both subvalvular interventions was associated with decreased distance of the anterior papillary muscle to the annular centroid. ConclusionsPapillary muscle approximations were effective in reducing severe ovine functional tricuspid regurgitation associated with right ventricular dilation and papillary muscle displacement. Further studies are needed to evaluate efficacy of this adjunct to ring annuloplasty in repair of severe functional tricuspid regurgitation.

Implications of the anatomy of papillary muscle connections for mapping and ablation of focal ventricular arrhythmias

Ventricular arrhythmias (VAs) originating from papillary muscles (PAPs) can be challenging when targeted with catheter ablation. Reasons may include premature ventricular complex pleomorphism, structurally abnormal PAPs, or unusual origins of VAs from PAP-myocardial connections (PAP-MYCs). The purpose of this study was to correlate PAP anatomy with mapping and ablation of PAP VAs. In a series of 43 consecutive patients with frequent PAP arrhythmias referred for ablation, the anatomy and structure of PAPs and VA origins were analyzed using multimodality imaging. Successful ablation sites were analyzed for location on the PAP body or a PAP-MYC. In a total of 17 of 43 patients (40%), VAs originated from a PAP-MYC (in 5 of 17 patients, the PAP inserted into the mitral valve anulus); and in 41 patients, VAs originated from a PAP body. VAs from a PAP-MYC more often had delayed R-wave transition than did other PAP VAs (69% vs 28%; P < .001). Patients with failed procedures had more PAP-MYCs (24.8 ± 8 PAP-MYCs per patient vs 16 ± 7 PAP-MYCs per patient; P < .001). Multimodality imaging identifies anatomic details of PAPs that facilitate mapping and ablation of VAs. In more than a third of patients with PAP VAs, VAs originate from connections between PAPs and the surrounding myocardium or between other PAPs. VA electrocardiographic morphologies are different when VAs originate from PAP-connection sites as compared with VAs originating from the PAP body.

Windows, Wings and Wonder: Advanced Cardiac Imaging Via Transesophageal Two-Dimensional and Transthoracic Three-Dimensional Echocardiography for the Accurate Diagnosis of Double-Orifice Mitral Valve in the Background of Primum Atrial Septal Defect: A Case Report

The assessment of mitral valve anatomy can be difficult or even misleading on standard cardiac imaging procedures. Such is the scenario in a 40-year-old woman with an incidental finding of atrial septal defect (ASD) and consideration of a trileaflet versus double-orifice mitral valve (DOMV) on transthoracic two-dimensional echocardiography. Further interrogation using transesophageal two-dimensional and transthoracic three-dimensional (3D) echocardiography (to allow more accurate assessment and simultaneous viewing of multiple imaging planes) revealed the typical “seagull wing” configuration of the mitral valve on long-axis view and two distinct but nearly equal-sized orifices on short-axis view, one oriented anteriorly and the other posteriorly. The patient’s DOMV was classified as an incomplete bridge type as confirmed on 3D imaging, with each orifice having its own set of papillary muscles and chordal attachments. The mitral regurgitation was graded as severe, resulting from leaflet prolapse of the anterior orifice. No left ventricular outflow tract obstruction was demonstrated in this case, and the overall left ventricular systolic function was preserved. The ASD was of the primum type, with the configuration and exact location verified through 3D imaging. The accurate detection of congenital anomalies via noninvasive techniques and complementary advanced modalities is vital for preoperative planning, as well as anticipation of potential complications related to the structural anomalies. To our knowledge, this is the first local report of DOMV with primum ASD in an adult. KEYWORDS: double-orifice mitral valve, primum atrial septal defect, transesophageal and three dimensional echocardiography

Is Congenital Muscular Mitral-Aortic Discontinuity Another Feature of Obstructive Hypertrophic Cardiomyopathy? A Pathology Validation Study

Hypertrophic cardiomyopathy (HCM) is an inherited myocardial disease at risk of sudden cardiac death and heart failure, even requiring heart transplantation. A “muscular mitral-aortic discontinuity” has been reported during surgery in the obstructive form. We aimed to validate these findings through pathological analysis of HCM heart specimens from the cardiovascular pathology tissue registry. Hearts with septal asymmetric HCM from sudden cardiac death, other causes of death, or heart transplantation were included. Sex-matched and age-matched patients without HCM served as controls. Gross and histologic analysis of the mitral valve (MV) apparatus and the mitral-aortic continuity were performed. Thirty HCM hearts (median age, 29.5 years; 15 men) and 30 controls (median age, 30.5 years; 15 men) were studied. In HCM hearts, a septal bulging was present in 80%, an endocardial fibrous plaque in 63%, a thickening of the anterior MV leaflet in 56.7%, and an anomalous insertion of papillary muscle in 10%. All cases but 1 (97%) revealed a myocardial layer overlapping the mitral-aortic fibrous continuity on the posterior side, corresponding to the left atrial myocardium. A negative correlation between the length of this myocardial layer and the age and the anterior MV leaflet length was found. The length did not differ between HCM and controls.Pathologic study of obstructive HCM hearts does not confirm the existence of a "muscular mitral-aortic discontinuity". An extension of left atrial myocardium, overlapping posteriorly the intervalvular fibrosa, is rather visible, and its length decreases with age, possibly as a consequence of left atrial remodeling. Our study highlights the fundamental role of thorough gross examination and the value of organ retention for further analysis in order to validate new surgical and imaging findings.

Biventricular isolated apical hypoplasia: First-time description of a new cardiac abnormality by multimodality imaging

Left ventricular isolated hypoplasia is a seldom-described cardiac abnormality. Right ventricular hypoplasia is usually associated with congenital anomalies of the pulmonary or the tricuspid valve, whereas biventricular isolated apical hypoplasia has never been described. We report the case of a 48-year-old man with no history of known cardiac disease who was found to have a complex cardiac abnormality characterized by: 1) Deficiency of the myocardium within the biventricular apex with adipose tissue infiltration; 2) Truncated right ventricle because of an absent trabecular portion of the inflow tract; 3) Truncated and spherical left ventricular apex; 4) Origin of the mitral papillary muscle in the flattened anterior left ventricular apex. Multimodality imaging was performed to delineate the morphological and functional characteristics of this cardiomyopathy fully. To the best of our knowledge, this is the first description of a new cardiac abnormality characterized by the hypoplasia of the apical region of both ventricles in the absence of valvular or coronary artery disease.

Features of Diagnostics and Course of Hypertrophic Cardiomyopathy in Real Clinical Practice

Introduction and purpose. Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular (LV) wall thickening not associated with increased afterload (hypertension and aortic stenosis), is usually caused by mutations in sarcomeric protein genes, and is inherited in an autosomal dominant manner. Unlike HCM, myocardial hypertrophy in its phenocopies is associated with the accumulation of substances such as amyloid, glycogen, etc. in the myocardium. The aim of our work was to analyze the features of the diagnosis and course of HCM in real clinical practice. Material and methods. A retrospective analysis of medical records of 80 patients (56.3 % of men) discharged with a diagnosis of HCM from a multidisciplinary hospital in Moscow in the period from 2007 to 2021 was carried out. The diagnosis of HCM in all patients was established on the basis of echocardiography data. The median age (25th and 75th percentiles are indicated in brackets) was 57 (48.5; 63) years. The duration of hospitalization was 8 (6; 12.5) days. Results. The reason for hospitalization was angina syndrome in 35 %, suspicion of acute coronary syndrome in 16.3 %, paroxysmal atrial fibrillation (AF) in 11.3 %, decompensation of chronic heart failure in 11.3 %, syncope in 7.5 % %, hypertensive crisis in 3.8 %, coronary angiography in 3.8 %, pacemaker implantation in 2.5 %, consultation with an arrhythmologist in 2.5 %, implantation of a cardioverter-defibrillator in 1.2 %, medical examination to resolve the issue of fitness for military service in 1.2 %, acute cerebrovascular accident in 1.2 %, hypotension in 1.2 %, drug bradycardia in 1.2 % of patients. Before hospitalization, a history of myocardial infarction was diagnosed in 15 %, arterial hypertension — in 53.8 %, chronic heart failure — in 77.6 %, chronic kidney disease — in 21.3 % of patients. Prior to the analyzed hospitalization, a history of myocardial infarction was diagnosed in 15 %, arterial hypertension in 53.8 %, chronic heart failure in 77.6 %, chronic kidney disease in 21.3 % of patients. LV wall thickness ≥1.5 cm was detected in 91.2 %, symmetrical form of hypertrophy — 22.1 %, apical — 5.2 %, papillary muscle hypertrophy — 1.3 %, interventricular septum — 71.4 % of patients. Permanent obstruction of the LV outflow tract (LVOTO) was detected in 62.8 % (9.0 % of patients had a history of septal reduction), transient LVOTO — in 1.3 %, non-obstructive HCM — in 35.9 %. The ejection fraction (EF) of the LV (according to Simpson) was 63 (55-70) %, CHF with reduced LV EF &lt;40 % was detected in 3.8 %, with a moderately reduced LV EF (40-49 %) — in 5 %, with preserved LV EF — in 68.8 % of patients. Anterior systolic movement of the anterior leaflet of the mitral valve occurred in 47.5 %, prolapse of the anterior leaflet of the mitral valve was described in 7.14 %. Mitral regurgitation was registered in 75 % of patients. 45 % of patients with HCM suffered from AF: permanent 15 %, paroxysmal 23.8 %, persistent 6.2 % of patients. During hospitalization, ventricular tachycardia was registered in 7.5 %, supraventricular tachycardia — 3.8 %, conduction disturbances were noted in 36.3 % of patients, of which atrioventricular block in 6.3 %, blockade of the right bundle branch block in 21.3 %, left bundle branch block in 15 %, and Wolff-Parkinson-White syndrome in 1.3 % . Implantation of a pacemaker in history was in 5 %, including in connection with MorgagniAdams-Stokes attacks — in 3.8 % of patients. During a median follow-up of 87 (interquartile range 45–131.5) months, 13.8 % of patients with HCM died. In deceased patients, LVOTO was significantly more common (in the dead 100 %, in the living 58.2 %, p = 0.006) and AF (in the dead 72.7 %, in the living 40.6 %, p = 0.047). Genetic testing and exclusion of HCM phenocopies was not performed during hospitalization and was not recommended for any patient. Conclusion. In real clinical practice, in most cases, only phenotypic diagnosis of HCM is carried out according to echocardiography, and screening for genetic mutations and HCM phenocopies is not performed. It is necessary to widely introduce genetic testing and screening for HCM phenocopies for the timely diagnosis of pathology that requires the appointment of specific pathogenetic therapy to improve the prognosis of patients

Effect of papillary muscle approximation on acute ovine functional tricuspid regurgitation.

Ring annuloplasty represents the standard surgical treatment, but offers suboptimal results in patients with severe functional tricuspid regurgitation. Addition of papillary muscles (PMs) approximation may improve clinical outcomes. Eight healthy adult male sheep (56 ± 4 kg) underwent cardiopulmonary bypass and implantation of sonomicrometry crystals on the tricuspid annulus, PM tips and right ventricular (RV) free wall. Papillary muscles approximation sutures were anchored between anterior-posterior and anterior-septal PMs and their loose ends externalized through RV free wall to epicardial tourniquets. After weaning from cardiopulmonary bypass, acute right heart failure and tricuspid regurgitation were induced, and subsequent sequential anterior-posterior and anterior-septal PM approximations were performed. Echocardiographic, haemodynamic and sonomicrometry data were collected. Tricuspid regurgitation at baseline in eight sheep was none or trace in 3 and mild in 5, and after induction of acute right heart failure increased significantly to moderate in 5, moderately severe in 1 and severe in 2 (P = 0.011). RV pressure increased from 31 [28; 43] to 51 [47; 55] mmHg (P = 0.012). Anterior-posterior PM approximation decreased regurgitation grade to none or trace in 1, mild in 4 and moderate in 3 (P = 0.016) and reduced PM area from 208 [160; 241] to 108 [48; 181] mm2 (P = 0.008), and anterior-posterior PM distance from 18 [16; 20] to 10 [7; 13] mm (P = 0.037). Anterior-septal approximation also significantly reduced PM area but had no effect on regurgitation grade. Anterior-posterior but not anterior-septal PM approximation alleviated acute ovine tricuspid regurgitation. Selective PM approximation may offer better control of tricuspid regurgitation.

Traumatic rupture of anterolateral papillary muscle in a patient with congenital deficiency of left hemi-pericardium: case report

Abstract Congenital absence or deficiency of the pericardium or hemi-pericardium is uncommon. When it happens, the protection given to the heart is greatly reduced, and blunt or penetrating trauma to the chest is transmitted directly to the heart. Valvular injuries from these traumas are however rare with a case of tricuspid valve rupture reported. Traumatic papillary muscle rupture in all patients group is also rare. Co-existing rupture of papillary muscle in patients with congenital absence of the pericardium is extremely rare. We report the rare case of a patient with deficient left hemi-pericardium who had a traumatic rupture of the anterolateral papillary muscle from a road traffic accident.

Transcatheter Mitral Valve Repair-Beyond the EVEREST and COAPT Criteria.

Transcatheter mitral valve repair (TMVr) has emerged as a safe and effective alternative to conventional surgery in patients with primary and secondary mitral regurgitation, especially those at high surgical risk. This review summarises alternative indications for TMVr outside of the traditional criteria derived from the major randomised trials and focusses on less common mitral valve anatomies such as commissural prolapse and bileaflet prolapse, patients with mitral annuloplasty rings, as well as acutely unwell patients with papillary muscle rupture and/or cardiogenic shock. Specific technical challenges involved in treating such patient groups are summarised and described.

Assessment of the mechanism of mitral valve prolapse in children: An echocardiography study.

The high complexity of mitral valve anatomy and function in mitral valve prolapse (MVP) is not yet fully understood. The purpose of this study was to analyze each part of the mitral valve apparatus in children to determine its impact on the presence of MVP and to assess the interaction between the coaptation length (CL) and mitral regurgitation severity. We prospectively analyzed transthoracic echocardiograms of 60 patients with MVP (mean age 9.8±3.1 years). We compared these patients with 60 control patients without disease. We determined length of leaflets, chordal length, tenting area, coaptation CL, the intrapapillary muscle distance (IPMD) and relation between CL and severity of mitral regurgitation (MR). For patients with MVP, the posterior mitral leaflet (PML) was significantly enlarged 13.9±4.1mm versus 10.7±3.5mm (p<.01), the primary chordal length was significantly decreased 15.4±3.61mm versus 17.6±3.8mm (p<.02), and IPMD was significantly greater 18.1±2.7mm versus 16.6±4.3mm (p<.03). The difference between CL for both the anterior and posterior mitral leaflets correlated positively with MR (r=.249, p<.05). A greater than 4mm CL correlated with at least MR (sensitivity 100%, specificity 72%) and greater than 5mm correlated with at least moderate MR (sensitivity 100%, specificity 60%). The majority of pediatric patients with mitral valve prolapse have structural abnormalities that are defined well by echocardiography. In addition to the presence of prolapse and regurgitation, routine assessment of leaflet length, thickness, chordal length and papillary muscle distance is fundamental for patients with MVP.

The role of papillary muscle abnormalities in hypertrophic cardiomyopathy: a new paradigm shift?

The role of papillary muscle abnormalities in hypertrophic cardiomyopathy: a new paradigm shift?

Cardiovascular Harmful Effects of Recommended Daily Doses (13µg/kg/day), Tolerable Upper Intake Doses (0.14mg/kg/day) and Twice the Tolerable Doses (0.28mg/kg/day) of Copper.

Copper is essential for homeostasis and regulation of body functions, but in excess, it is a cardiovascular risk factor since it increases oxidative stress. The objective of this study was to evaluate the effects of exposure to the recommended daily dose (13µg/kg/day), upper tolerable dose (0.14mg/kg/day) and twice the upper tolerable dose (0.28mg/kg/day) via i.p. over 4weeks on the vascular reactivity of aortic rings and the contraction of LV papillary muscles of male Wistar rats. It was also determined whether the antioxidant peptide from egg white hydrolysate (EWH) prevents these effects. Copper exposure at the doses evaluated did not change weight gain of male Wistar rats, the reactivity of the aortic rings or the cardiac mass. The dose of 0.13µg/kg/day did not reduce the force of contraction, but it impaired the time derivatives of force. Doses of 0.14 and 0.28mg/kg/day reduced the force of contraction, the inotropic response to calcium and isoproterenol, the postrest contraction and the peak and plateau of tetanized contractions. EWH treatment antagonized these effects. These results suggest that copper, even at the dose described as upper tolerable, can impair cardiac contraction without altering vascular reactivity. Antioxidative stress therapy with EWH reversed these harmful effects, suggesting a possible strategy for the amelioration of these effects.

Automatic Left Ventricle Segmentation from Short-Axis MRI Images Using U-Net with Study of the Papillary Muscles’ Removal Effect

Automatic Left Ventricle Segmentation from Short-Axis MRI Images Using U-Net with Study of the Papillary Muscles’ Removal Effect

Safety and efficacy of bipolar radiofrequency catheter ablation in ventricular arrhythmias of mural vs non-mural origin

Abstract Funding Acknowledgements Type of funding sources: None. Background Bipolar radiofrequency catheter ablation (B-RFA) has shown promising results in refractory ventricular arrhythmia (VA) of septal origin and underlying non-ischemic cardiomyopathy (NICM). However, its efficacy and safety in other locations such as the free wall and papillary muscles (PM) has not yet been fully determined. Purpose To describe and analyse the procedural data, safety and efficacy results of B-RFA in a cohort of patients with VA of different locations and underlying substrate. Methods We enrolled 21 patients with recurrent VA after prior failed ablation into this study, of whom 16 patients required B-RFA for effective ablation. Seven of the patients had ventricular ectopy (VE) and 9 presented with ventricular tachycardia (VT). During B-RFA, a contact-force-sensing, saline-irrigated catheter was connected to the ablation catheter connection on the radiofrequency generator and a second ablation catheter (saline-irrigated in 6 of the cases) was connected to the ground patch terminal through a custom-made switch box. This allowed visualization of both catheters on the 3D mapping system and acquisition of electrograms from both simultaneously. Procedure data, related complications and acute and long-term outcomes during follow-up were assessed. Results The VA distribution was septal (31.3%, n=5), PM (31.3%, n=5), right ventricle free wall (18.8%, n=3), left ventricle (LV) free wall (12.5%, n=2) and LV summit (6.3%, n=1). Compared to septal ablation, contact force obtained during B-RFA ablation was significantly lower in PM ablation (p=0.01), as was the impedance drop (p=0.03). There were no significant differences in the number of energy applications, their mean duration, the total ablation time, the power and the temperature among locations. Acute success was achieved in 15 patients (93.6%). Long-term success, defined as no recurrence of sustained VT or less than 1% VE burden on 24-hour Holter at 12-month follow up, was achieved in 11 patients (68.8%), and another 2 patients (12.5%) had partial success. Papillary muscle VA had lower acute and long-term success (80% and 60%, respectively) after B-RFA. On the other hand, patients with NICM appeared to have superior outcomes (figure 1). No steam pops or major peri-procedural complications were observed. However, the use of a non-irrigated indifferent electrode resulted in char formation. Conclusions B-RFA can be used successfully and safely in NICM involving the septum and free walls but has limited use for PM arrhythmias. This could be related to a lack of catheter stability and reduced energy transfer. In addition, when using B-RFA, any catheter in the circulatory system should be irrigated.