Papillary Muscle Research Articles

Automatic left ventricle volume and mass quantification from 2D cine-MRI: Investigating papillary muscle influence

ObjectiveEarly detection of cardiovascular diseases is based on accurate quantification of the left ventricle (LV) function parameters. In this paper, we propose a fully automatic framework for LV volume and mass quantification from 2D-cine MR images already segmented using U-Net. MethodsThe general framework consists of three main steps: Data preparation including automatic LV localization using a convolution neural network (CNN) and application of morphological operations to exclude papillary muscles from the LV cavity. The second step consists in automatically extracting the LV contours using U-Net architecture. Finally, by integrating temporal information which is manifested by a spatial motion of myocytes as a third dimension, we calculated LV volume, LV ejection fraction (LVEF) and left ventricle mass (LVM). Based on these parameters, we detected and quantified cardiac contraction abnormalities using Python software. ResultsCNN was trained with 35 patients and tested on 15 patients from the ACDC database with an accuracy of 99,15 %. U-Net architecture was trained using ACDC database and evaluated using local dataset with a Dice similarity coefficient (DSC) of 99,78 % and a Hausdorff Distance (HD) of 4.468 mm (p < 0,001). Quantification results showed a strong correlation with physiological measures with a Pearson correlation coefficient (PCC) of 0,991 for LV volume, 0.962 for LVEF, 0.98 for stroke volume (SV) and 0.923 for LVM after pillars’ elimination. Clinically, our method allows regional and accurate identification of pathological myocardial segments and can serve as a diagnostic aid tool of cardiac contraction abnormalities. ConclusionExperimental results prove the usefulness of the proposed method for LV volume and function quantification and verify its potential clinical applicability.

Mid-term outcomes of right ventricular papillary muscle approximation for severe functional tricuspid regurgitation.

Recurrence of tricuspid regurgitation (TR) after tricuspid annuloplasty can occur in cases where a dilated right ventricle exists and subsequent leaflet tethering follows. We previously reported a new technique of the right ventricular papillary muscle approximation (RV-PMA) for functional TR associated with leaflet tethering. The objective of this study is to elucidate the mid-term outcomes and evaluate the durability of RV-PMA. Between January 2014 and March 2023, we applied RV-PMA in 20 patients of advanced functional TR with severe leaflet tethering. The indication of the technique was severe TR with leaflet tethering height >8 mm, and/or a right ventricular end-diastolic diameter >45 mm. The patients were followed up with echocardiography before discharge and at annual interval thereafter. There was no perioperative mortality. In the echocardiography performed before discharge, TR was decreased to mild or less in 85%, and a significant improvement in right ventricular end-diastolic diameter and tethering height were achieved (53-45 mm and 11.1-4.4 mm, respectively). Furthermore, during the median 3-year follow-up period, TR was kept controlled mild or less in 80% of the cases. RV-PMA is considered to be a safe, effective and durable technique as an additional approach for tricuspid annuloplasty.

Intramural needle ablation or repeated standard ablation in patients referred for repeat ablation of scar-related ventricular tachycardia.

When ventricular tachycardia (VT) recurs after standard RF ablation (sRFA) some patients benefit from repeat sRFA, whereas others warrant advanced methods such as intramural needle ablation (INA). Our objectives are to assess the utility of repeat sRFA and to clarify the benefit of INA when repeat sRFA fails in patients with VT due to structural heart disease. In consecutive patients who were prospectively enrolled in a study for INA for recurrent sustained monomorphic VT despite sRFA, repeat sRFA was considered first. INA was performed during the same procedure if repeat sRFA failed or no targets for sRFA were identified. Of 85 patients enrolled, acute success with repeat sRFA was achieved in 30 patients (35%), and during the 6-month follow-up, 87% (20/23) were free of VT hospitalization, 78% were free of any VT, and 7 were lost to follow-up. INA was performed in 55 patients (65%) after sRFA failed, or no endocardial targets were found abolished or modified inducible VT in 35/55 patients (64%). During follow-up, 72% (39/54) were free of VT hospitalization, 41% were free of any VT, and 1 was lost to follow-up. Overall, 59 out of 77 (77%) patients were free of hospitalization and 52% were free of any VT. Septal-origin VTs were more likely to need INA, whereas RV and papillary muscle VTs were less likely to require INA. Repeat sRFA was beneficial in 23% (18/77) of patients with recurrent sustained VT who were referred for INA. The availability of INA increased favorable outcomes to 52%.

The active papillary muscle sign in 18F-FDG PET/CT cardiac sarcoidosis exams and its relationship with myocardial suppression.

Papillary muscle (PM) activity may demonstrate true active cardiac sarcoidosis (CS) or mimic CS in 18FDG-PET/CT if adequate myocardial suppression (MS) is not achieved. We aim to examine whether PM uptake can be used as a marker of failed MS and measure the rate of PM activity presence in active CS with different dietary preparations. We retrospectively reviewed PET/CTs obtained with three different dietary preparations. Diet-A: 24-h ketogenic diet with overnight fasting (n = 94); Diet-B: 18-h fasting (n = 44); and Diet-C: 72-h daytime ketogenic diet with 3-day overnight fasting (n = 98). Each case was evaluated regarding CS diagnosis (negative, positive, and indeterminant) and presence of PM activity. MaxSUV was measured from bloodpool, liver, and the most suppressed normal myocardium. Linear mixed-effects models were used to compare these factors between those with PM activity and those without. PM activity was markedly lower in the Diet-C group compared with others: Diet-C: 6 (6.1%), Diet-A: 36 (38.3%), and Diet-B: 26 (59.1%) (p < 0.001). MyocardiumMaxSUV was higher, and MyocardiummaxSUV/BloodpoolmaxSUV, MyocardiummaxSUV/LivermaxSUV ratios were significantly higher in the cases with PM activity (p < 0.001). Among cases that used Diet-C and had PM activity, 66.7% were positive and 16.7% were indeterminate. If Diet-A or Diet-B was used, those with PM activity had a higher proportion of indeterminate cases (Diet-A: 61.1%, Diet-B: 61.5%) than positive cases (Diet-A: 36.1%, Diet-B: 38.5%). Lack of PM activity can be a sign of appropriate MS. PM activity is less common with a specific dietary preparation (72-h daytime ketogenic diet with 3-day overnight fasting), and if it is present with this particular preparation, the likelihood that the case being true active CS might be higher than the other traditional dietary preparations.

A tissue-silicone integrated simulator for right ventricular pulsatile circulation with severe functional tricuspid regurgitation

There is a great demand for development of a functional tricuspid regurgitation (FTR) model for accelerating development and preclinical study of tricuspid interventional repair devices. This study aimed to develop a severe FTR model by creating a tissue-silicone integrated right ventricular pulsatile circulatory simulator. The simulator incorporates the porcine tricuspid annulus, valve leaflets, chordae tendineae, papillary muscles, and right ventricular wall as one continuous piece of tissue, thereby preserving essential anatomical relationships of the tricuspid valve (TV) complex. We dilated the TV annulus with collagenolytic enzymes under applying stepwise dilation, and successfully achieved a severe FTR model with a regurgitant volume of 45 ± 9 mL/beat and a flow jet area of 15.8 ± 2.3 cm2 (n = 6). Compared to a normal model, the severe FTR model exhibited a larger annular circumference (133.1 ± 8.2 mm vs. 115.7 ± 5.5 mm; p = 0.009) and lower coaptation height (6.6 ± 1.0 mm vs. 17.7 ± 1.3 mm; p = 0.003). Following the De-Vega annular augmentation procedure to the severe FTR model, a significant reduction in regurgitant volume and flow jet area were observed. This severe FTR model may open new avenues for the development and evaluation of transcatheter TV devices.

Resection of hypertrophic papillary muscles and mitral valve replacement in a patient with midventricular hypertrophic obstructive cardiomyopathy – a new approach

Midventricular hypertrophic obstructive cardiomyopathy (HOCM) is characterized by hypertrophy of the interventricular septum (IVS) and - in rare cases - of the papillary muscles (PM), which subsequently can cause dynamic left ventricular outflow tract obstruction (LVOTO) and severe heart failure symptoms. We report on a rare case of a 44-year-old patient suffering from midventricular HOCM with hypertrophic anterolateral PM and an additional chorda between the PM and the IVS.We describe a new surgical approach via right anterolateral thoracotomy in 3-dimensional (3D) video-assisted minimal-invasive technique with resection of hypertrophic PMs as well as the entire mitral valve-apparatus and valve replacement avoiding septal myectomy and potentially associated complications. After an uneventful procedure clinical symptoms improved from NYHA III-IV at baseline to NYHA 0-I postoperatively and remained stable over a follow-up period of 24 months. Therefore, the presented technique may be considered as a new and alternative approach in patients with hypertrophic PMs and hypertrophic IVS as subtype of midventricular HOCM.

A Motion-Aware DNN Model with Edge Focus Loss and Quality Control for Short-Axis Left Ventricle Segmentation of Cine MR Sequences.

Accurate segmentation of the left ventricle myocardium is the key step of automatic assessment of cardiac function. However, the current methods mainly focus on the end-diastolic and the end-systolic frames in cine MR sequences and lack the attention to myocardial motion in the cardiac cycle. Additionally, due to the lack of fine segmentation tools, the simplified approach, excluding papillary muscles and trabeculae from myocardium, is applied in clinical practice. To solve these problems, we propose a motion-aware DNN model with edge focus loss and quality control in this paper. Specifically, the bidirectional ConvLSTM layer and a new motion attention layer are proposed to encode motion-aware feature maps, and an edge focus loss function is proposed to train the model to generate the fine segmentation results. Additionally, a quality control method is proposed to filter out the abnormal segmentations before subsequent analyses. Compared with state-of-the-art segmentation models on the public dataset and the in-house dataset, the proposed method has obtained high segmentation accuracy. On the 17-segment model, the proposed method has obtained the highest Pearson correlation coefficient at 14 of 17 segments, and the mean PCC of 85%. The experimental results highlight the segmentation accuracy of the proposed method as well as its availability to substitute for the manually annotated boundaries for the automatic assessment of cardiac function.

A Rare Case of Left Ventricle Free Wall Rupture at two sites Secondary to Myocardial Infarction: An Autopsy Case

Background: About 40–50% of occurrences of sudden death are due to cardiovascular reasons, with acute myocardial infarction (AMI) being the most common cause. Case Details: The subject was 57 years male having alleged history of sudden fell down at his house and was unresponsive since then. He was brought to the Emergency Department of H.N.B Base hospital Srinagar, Garhwal, Uttarakhand. Autopsy Findings: On opening pericardium, 190 grams of clotted blood was present in the pericardial cavity. Grossly enlarged heart. Weight of heart: 560 grams. Epicardial fat covers approx. 2/3rd of the heart’s surface. It is present over the right ventricle especially along the right border, anterior surface and at the apex and along the distribution of coronary arteries. Discussion: A myocardial rupture is the rupturing of one or more heart valves, the papillary muscles or chordae tendineae, the interatrial or interventricular septum, or the ventricles or atria of the heart.

Effects of the Heterodimeric Neurotoxic Phospholipase A2 from the Venom of Vipera nikolskii on the Contractility of Rat Papillary Muscles and Thoracic Aortas.

Phospholipases A2 (PLA2s) are a large family of snake toxins manifesting diverse biological effects, which are not always related to phospholipolytic activity. Snake venom PLA2s (svPLA2s) are extracellular proteins with a molecular mass of 13-14 kDa. They are present in venoms in the form of monomers, dimers, and larger oligomers. The cardiovascular system is one of the multiple svPLA2 targets in prey organisms. The results obtained previously on the cardiovascular effects of monomeric svPLA2s were inconsistent, while the data on the dimeric svPLA2 crotoxin from the rattlesnake Crotalus durissus terrificus showed that it significantly reduced the contractile force of guinea pig hearts. Here, we studied the effects of the heterodimeric svPLA2 HDP-1 from the viper Vipera nikolskii on papillary muscle (PM) contractility and the tension of the aortic rings (ARs). HDP-1 is structurally different from crotoxin, and over a wide range of concentrations, it produced a long-term, stable, positive inotropic effect in PMs, which did not turn into contractures at the concentrations studied. This also distinguishes HDP-1 from the monomeric svPLA2s, which at high concentrations inhibited cardiac function. HDP-1, when acting on ARs preconstricted with 10 μM phenylephrine, induced a vasorelaxant effect, similar to some other svPLA2s. These are the first indications of the cardiac and vascular effects of true vipers' heterodimeric svPLA2s.

Minimally Invasive Mitral Valve Repair: From Total Endoscopic To Closed-Chest Robotic.

Minimally invasive cardiac surgery has evolved over the past few decades, thanks to advancements in technology and surgical techniques. These advancements have allowed surgeons to perform cardiac interventions through small incisions, reducing surgical trauma and improving patient outcomes1. However, despite these advancements, thoracoscopic mitral repair has not been widely adopted by the cardiac surgery community, possibly due to the lack of familiarity with video-assisted procedures1. Over the years, various minimally invasive mitral valve surgery (MIMVS) techniques have been developed to achieve comparable or better results while minimizing surgical trauma. These techniques have evolved from direct-vision procedures performed through a right thoracotomy with a rib retractor to video-directed approaches using long-shafted instruments1. Robotic surgery, introduced in the late 90s, has also played a significant role in mitral valve repair. The da Vinci system, the only robotic platform currently used for cardiac surgery, provides surgeons with enhanced dexterity and high-definition 3D visualization, allowing for precise and accurate procedure2, and is now the preferred approach for mitral repair in many programs3. The first mitral repair using the da Vinci system was performed in Europe by Carpentier and Mohr in 1998, followed by the first mitral replacement by Chitwood in the USA in 20002-4. The advantages of robotic technology allow surgeons to perform complex repair techniques such as papillary muscle repositioning and sliding leaflet plasty4. Studies have shown that robotic mitral surgery results in shorter ICU and hospital stays, better quality of life postoperatively, and improved cosmesis compared to conventional surgery5,6. In our experience, we have also observed significant benefits with robotic surgery, including reduced blood loss and the need for transfusions. This can be attributed to the closed-chest technique, which eliminates the need for a thoracotomy and rib retractor, reducing the risk of bleeding associated with these approaches7. In this article, we will compare the surgical steps of endoscopic and robotic mitral valve repair, providing detailed information on patient selection, operative techniques, and the requirements for building a successful program. By understanding the advantages and challenges of both approaches, surgeons can make informed decisions and provide the best possible care for their patients. Combined ablation and multivalvular procedures are mostly performed in few centers by minimally invasive techniques.

Long-term survival after surgical treatment for post-infarction mechanical complications: results from the Caution study.

Mechanical complications (MCs) are rare but potentially fatal sequelae of acute myocardial infarction (AMI). Surgery, though challenging, is considered the treatment of choice. The authors sought to study early and long-term results of patients undergoing surgical treatment for post-AMI MCs. Patients undergone surgical treatment for post-infarction MCs between 2001 through 2019 in 27 centers worldwide were retrieved from the database of CAUTION study. In-hospital and long-term mortality were the primary outcomes. Cox proportional hazards regression models were used to determine independent factors associated with overall mortality. The study included 720 patients. The median age was 70.0 [62.0-77.0] years, with a male predominance (64.6%). The most common MC encountered was ventricular septal rupture (VSR) (59.4%). Cardiogenic shock was seen on presentation in 56.1% of patients. In-hospital mortality rate was 37.4%; in more than 50% of cases, the cause of death was low cardiac output syndrome (LCOS). Late mortality occurred in 133 patients, with a median follow-up of 4.4 [1.0-8.6] years. Overall survival at 1, 5 and 10 years was 54.0%, 48.1% and 41.0%, respectively. Older age (p<0.001) and postoperative LCOS (p<0.001) were independent predictors of overall mortality. For hospital survivors, 10-year survival was 65.7% and was significant higher for patients with VSR than those with papillary muscle rupture (long-rank P=0.022). Contemporary data from a multicenter cohort study show that surgical treatment for post-AMI MCs continues to be associated with high in-hospital mortality rates. However, long-term survival in patients surviving the immediate postoperative period is encouraging.Trial registration number: NCT03848429.

Meta-Analysis of Normal Reference Values for Right and Left Ventricular Quantification by Cardiovascular Magnetic Resonance.

Cardiovascular magnetic resonance (CMR) reference values are relied upon to accurately diagnose left ventricular (LV) and right ventricular (RV) pathologies. To date, reference values have been derived from modest sample sizes with limited patient diversity and attention to 1 but not both commonly used tracing techniques for papillary muscles and trabeculations. We sought to overcome these limitations by meta-analyzing normal reference values for CMR parameters stemming from multiple countries, vendors, analysts, and patient populations. We comprehensively extracted published and unpublished data from studies reporting CMR parameters in healthy adults. A steady-state free-precession short-axis stack at 1.5T or 3T was used to trace either counting the papillary muscles and trabeculations in the LV volume or mass. We used a novel Bayesian hierarchical meta-analysis model to derive the pooled lower and upper reference values for each CMR parameter. Our model accounted for the expected differences between tracing techniques by including informative prior distributions from a large external data set. A total of 254 studies from 25 different countries were systematically reviewed, representing 12 812 healthy adults, of which 52 were meta-analyzed. For LV parameters counting papillary muscles and trabeculations in the LV volume, pooled normative reference ranges in men and women, respectively, were as follows: LV ejection fraction of 52% to 73% and 54% to 75%, LV end-diastolic volume index of 60 to 109 and 56 to 96 mL/m2, LV end-systolic volume index of 18 to 45 and 16 to 38 mL/m2, and LV mass index of 41 to 76 and 33 to 57 g/m2. For LV parameters counting papillary muscles and trabeculations in the LV mass, pooled normative reference ranges in men and women, respectively, were as follows: LV ejection fraction of 57% to 74% and 57% to 75%, LV end-diastolic volume index of 60 to 97 and 55 to 88 mL/m2, LV end-systolic volume index of 18 to 37 and 15 to 34 mL/m2, and LV mass index of 50 to 83 and 38 to 65 g/m2. For RV parameters, pooled normative reference ranges in men and women, respectively, were as follows: RV ejection fraction of 47% to 68% and 49% to 71%, RV end-diastolic volume index of 64 to 115 and 57 to 99 mL/m2, RV end-systolic volume index of 23 to 52 and 18 to 42 mL/m2, and RV mass index of 14 to 29 and 13 to 25 g/m2. Our Bayesian hierarchical meta-analysis provides normative reference values for CMR parameters of LV and RV size, systolic function, and mass, encompassing both tracing techniques across a diverse multinational sample of healthy men and women.

Transcatheter edge-to-edge repair in papillary muscle injury complicating acute myocardial infarction.

Acute mitral regurgitation (MR) in the setting of myocardial infarction (MI) may be the result of papillary muscle rupture (PMR). This condition is associated with high morbidity and mortality. We aim to evaluate the feasibility of transcatheter edge-to-edge mitral valve repair (TEER) in this acute setting. We analysed data from the International Registry of MitraClip in Acute Mitral Regurgitation following acute Myocardial Infarction (IREMMI) of 30 centres in Europe, North America, and the middle east. We included patients with post-MI PMR treated with TEER as a salvage procedure, and we evaluated immediate and 30-day outcomes. Twenty-three patients were included in this analysis (9 patients suffered complete papillary muscle rupture, 9 partial and 5 chordal rupture). The patients' mean age was 68±14years. Patients were at high surgical risk with median EuroSCORE II 27% (IQR 16, 28) and 20 out of 23 (87% were in cardiogenic shock). All patients were treated with vasopressors, and 17 out of 23 patients required mechanical support. TEER procedure was performed on the median 6days after the index MI date IQR (3, 11). Procedural success was achieved in 87% of patients. The grade of MR was significantly decreased after the procedure. MR reduction to 0 or 1+was achieved in 13 patients (57%), to 2+in 7 patients (30%), P<0.01. V-Wave was reduced from 49±8mmHg to 26±10mmHg post-procedure, P<0.01. Sixteen out of 23 patients (70%) were discharged from hospital and 5 of them required reintervention with surgical mitral valve replacement. No additional death at 1year was documented. TEER is a feasible therapy in critically ill patients with PMR due to a recent MI. TEER may have a role as salvage treatment or bridge to surgery in this population.

Studies of Ca2+-activated contractility using skinned cryosections of human ventricular papillary muscle samples from frozen storage of discarded clinical specimens collected in biorepository

Studies of Ca2+-activated contractility using skinned cryosections of human ventricular papillary muscle samples from frozen storage of discarded clinical specimens collected in biorepository

Morphological Assessment and Possible Clinical Implications of the Left Ventricle Papillary Muscles. Study in a Colombian Population Sample

Morphological Assessment and Possible Clinical Implications of the Left Ventricle Papillary Muscles. Study in a Colombian Population Sample

Echocardiographic quantification of mitral apparatus morphology and dynamics in patients with dilated cardiomyopathy.

Mitral regurgitation is among the most common valvular heart diseases. Mitral regurgitation in patients with dilated cardiomyopathy is a complex pathology involving annular dilatation, papillary muscle displacement, systolic leaflet tethering, and left ventricular remodeling. Quantification of mitral apparatus damage in these patients is essential for successful interventional and surgical therapy. Mitral regurgitation in the presence of dilated cardiomyopathy is classified as Carpentier type IIIB, with restricted leaflet mobility as a standard feature. Echocardiography allows accurate evaluation of the complex anatomy and function of the mitral apparatus. Updated guidelines recommend two-dimensional followed by systematic three-dimensional echocardiographic evaluation in patients with mitral regurgitation. New three-dimensional echocardiographic software packages provide many parameters that help identify the precise morphology and function of the various components of the mitral apparatus, helping to determine the etiology of mitral regurgitation and evaluate disease severity. This review provides the first point-by-point approach to the assessment of all old and new echocardiographic methods, from the simplest to the most complex, used to examine the components of the mitral valve apparatus in patients with dilated cardiomyopathy. Although these parameters are still under research, this information will be helpful for establishing therapeutic procedures in a disease with a poor prognosis.

Posterior Papillary Muscle Suspension for Treating Systolic Anterior Motion in Hypertrophic Obstructive Cardiomyopathy.

Systolic anterior motion of the anterior mitral leaflet can persist after ventricular septal myectomy for obstructive hypertrophic cardiomyopathy, resulting in residual pressure gradients and mitral regurgitation. However, additional procedures for systolic anterior motion involving mitral valve leaflet suturing and resection may lead to future valve disease. Therefore, we adopted posterior papillary muscle suspension, a subvalvular procedure for functional mitral regurgitation, to treat systolic anterior motion without directly intervening in the mitral valve leaflets. Papillary muscle suspension toward the posterior mitral annulus moved the papillary muscles away from the interventricular septum and successfully eliminated the systolic anterior motion and midventricular pressure gradient. In terms of avoiding direct mitral interventions, this procedure is a viable option for systolic anterior motion, especially in cases of very mild mitral regurgitation.

Hydrocortisone cardioprotection in ischaemia/reperfusion injury involves antioxidant mechanisms.

Glucocorticoid (GR) and mineralocorticoid (MR) receptors are highly expressed in cardiac tissue, and both can be activated by corticosteroids. MR activation, in acute myocardial infarction (AMI), worsens cardiac function, and increase NHE activity contributing to the deleterious process. In contrast, effects of GR activation are not fully understood, probably because of the controversial scenario generated by using different doses or potencies of corticosteroids. We tested the hypothesis that an acute dose of hydrocortisone (HC), a low-potency glucocorticoid, in a murine model of AMI could be cardioprotective by regulating NHE1 activity, leading to a decrease in oxidative stress. Isolated hearts from Wistar rats were subjected to regional ischemic protocol. HC (10 nmol/L) was added to the perfusate during early reperfusion. Infarct size and oxidative stress were determined. Isolated papillary muscles from non-infarcted hearts were used to evaluate HC effect on sodium-proton exchanger 1 (NHE1) by analysing intracellular pH recovery from acute transient acidosis. HC treatment decreased infarct size, improved cardiac mechanics, reduced oxidative stress after AMI, while restoring the decreased level of the pro-fusion mitochondrial protein MFN-2. Co-treatment with the GR-blocker Mifepristone avoided these effects. HC reduced NHE1 activity by increasing the NHE1 pro-inhibiting Ser648 phosphorylation site and its upstream kinase AKT. HC restored the decreased AKT phosphorylation and anti-apoptotic BCL-2 protein expression detected after AMI. Our results provide the first evidence that acute HC treatment during early reperfusion induces cardioprotection against AMI, associated with a non-genomic HC-triggered NHE1 inhibition by AKT and antioxidant action that might involves mitochondrial dynamics improvement.

Mitral regurgitation mechanisms related to systolic anterior motion in hypertrophic cardiomyopathy.

Systolic anterior motion (SAM) of the mitral valve can result in mitral regurgitation (MR) and adverse outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM). However, the mechanism and characteristics of MR severity mediated by SAM are unresolved. This study aimed to elucidate the anatomic and hemodynamic associations of MR and the impact of septal myectomy on changes in MR severity in patients with HCM. We retrospectively reviewed patients who underwent septal myectomy with SAM and interpretable imaging between 2017-2022. Significant MR was defined as moderate or more MR. The mitral valve, papillary muscle, and left ventricular geometry were quantitatively evaluated via echocardiography and cardiac computed tomography. Out of 34 patients, two groups were identified: those with preoperative significant MR (n=16) and those without significant MR (n=18). Patients with significant preoperative MR exhibited worse heart failure symptoms at baseline than those without. Following myectomy, these patients showed higher residual left ventricular outflow tract (LVOT) gradients at rest and with provocative measures than those without preoperative MR. Multivariate regression analysis revealed a significant association between the tenting area and MR severity. Additionally, the chordal cutting procedure alleviated the tenting area [2.1 (1.8-2.6) vs. 1.4 (1.2-1.6) cm2] compared to those without it. Our preliminary data suggested that chordal cutting with septal myectomy was associated with an improvement in the tenting area, contributing to MR severity. This procedure may serve as an effective therapy for patients with SAM and significant MR.

A rare case of hydatid cyst in the chordae tendineae of papillary muscle of the right ventricle

A rare case of hydatid cyst in the chordae tendineae of papillary muscle of the right ventricle