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Echocardiography (Mount Kisco, N.Y.) Oct 2021
Topics: Humans; Mitral Valve; Mitral Valve Insufficiency; Papillary Muscles
PubMed: 34585418
DOI: 10.1111/echo.15204 -
The Journal of Cardiovascular Surgery Feb 2022Mitral valve repair with papillary muscle approximation (MVr-PMA) for severe secondary mitral regurgitation (MR) decreases MR recurrence compared with MVr alone. This...
BACKGROUND
Mitral valve repair with papillary muscle approximation (MVr-PMA) for severe secondary mitral regurgitation (MR) decreases MR recurrence compared with MVr alone. This study assessed the effects of MVr-PMA on left ventricular (LV) remodeling and shape, systolic function and strain mechanics.
METHODS
Forty-eight patients who underwent MVr-PMA for severe secondary MR and had follow-up echocardiograms available for review were identified. Student's t-test, linear regression modeling, and receiver-operating characteristic curves were used in the statistical analyses.
RESULTS
Median follow-up time was 14.9 months. MVr-PMA was associated with significant LV reverse remodeling with a smaller LV end-diastolic diameter, Systolic Sphericity Index, and interpapillary muscle distance at follow-up. Nine patients (18.8%) experienced moderate recurrent MR. When compared to recurrent MR patients at follow-up, those with durable MVr-PMA had a greater LV ejection fraction (32.8 vs. 22.0%, P=0.03), a smaller end-diastolic diameter (59.6 vs. 67.3 mm, P=0.03), Systolic Sphericity Index (0.35 vs. 0.47, P=0.03), and end-systolic interpapillary muscle distance (16.3 vs. 21.1 mm, P=0.03). A durable MVr-PMA also resulted in stable global longitudinal strain when compared with pre-operative values, while the recurrent MR group experienced a further decline (no recurrent MR: -8.4 vs. -7.5%; recurrent MR: -8.2 vs. -5.4%; P<0.05). A pre-operative LV end-diastolic diameter ≥ 64 mm was a discriminative predictor of MR recurrence (sensitivity=100%, specificity=51%, AUC=0.756, P=0.02).
CONCLUSIONS
A durable MVr-PMA confers improved LV geometry and function, and stable LV mechanics. The extent of baseline LV remodeling identifies patients at risk for recurrent MR.
Topics: Biomechanical Phenomena; Echocardiography; Humans; Mitral Valve; Mitral Valve Annuloplasty; Mitral Valve Insufficiency; Papillary Muscles; Recovery of Function; Recurrence; Severity of Illness Index; Systole; Time Factors; Treatment Outcome; Ventricular Function, Left; Ventricular Remodeling
PubMed: 34057163
DOI: 10.23736/S0021-9509.21.11843-9 -
Heart (British Cardiac Society) Aug 2023Ventricular secondary mitral regurgitation (SMR) (Carpentier type IIIb) results from left ventricular (LV) remodelling, displacement of papillary muscles and tethering... (Clinical Trial)
Clinical Trial
OBJECTIVE
Ventricular secondary mitral regurgitation (SMR) (Carpentier type IIIb) results from left ventricular (LV) remodelling, displacement of papillary muscles and tethering of mitral leaflets. The most appropriate treatment approach remains controversial. We aimed to assess the safety and efficacy of standardised relocation of both papillary muscles (subannular repair) at 1-year follow-up (FU).
METHODS
REFORM-MR (Reform-Mitral Regurgitation) is a prospective, multicentre registry that enrolled consecutive patients with ventricular SMR (Carpentier type IIIb) undergoing standardised subannular mitral valve (MV) repair in combination with annuloplasty at five sites in Germany. Here, we report survival, freedom from recurrence of MR >2+, freedom from major adverse cardiac and cerebrovascular events (MACCEs), including cardiovascular death, myocardial infarction, stroke, MV reintervention and echocardiographic parameters of residual leaflet tethering at 1-year FU.
RESULTS
A total of 94 patients (69.1% male) with a mean age of 65.1±9.7 years met the inclusion criteria. Advanced LV dysfunction (mean left ventricular ejection fraction 36.4±10.5%) and severe LV dilatation (mean left ventricular end-diastolic diameter 61.0±9.3 mm) resulted in severe mitral leaflet tethering (mean tenting height 10.6±3.0 mm) and an elevated mean EURO Score II of 4.8±4.6 prior to surgery. Subannular repair was successfully performed in all patients, without operative mortality or complications. One-year survival was 95.5%. At 12 months, a durable reduction of mitral leaflet tethering resulted in a low rate (4.2%) of recurrent MR >2+. In addition to a significant improvement in New York Heart Association (NYHA) class (22.4% patients in NYHA III/IV vs 64.5% patients at baseline, p<0.001), freedom from MACCE was observed in 91.1% of patients.
CONCLUSIONS
Our study demonstrates the safety and feasibility of standardised subannular repair to treat ventricular SMR (Carpentier type IIIb) in a multicentre setting. By addressing mitral leaflet tethering, papillary muscle relocation results in very satisfactory 1-year outcomes and has the potential to durably restore MV geometry; nevertheless, long-term FU is mandatory.
TRIAL REGISTRATION NUMBER
NCT03470155.
Topics: Aged; Female; Humans; Male; Middle Aged; Mitral Valve Annuloplasty; Mitral Valve Insufficiency; Prospective Studies; Stroke Volume; Systole; Treatment Outcome; Ventricular Function, Left
PubMed: 37376817
DOI: 10.1136/heartjnl-2022-322239 -
Contractility detection of isolated mouse papillary muscle using myotronic Myostation-Intact device.Animal Models and Experimental Medicine Oct 2022To understand the relationship between myocardial contractility and external stimuli, detecting ex vivo myocardial contractility is necessary.
BACKGROUND
To understand the relationship between myocardial contractility and external stimuli, detecting ex vivo myocardial contractility is necessary.
METHODS
We elaborated a method for contractility detection of isolated C57 mouse papillary muscle using Myostation-Intact system under different frequencies, voltages, and calcium concentrations.
RESULTS
The results indicated that the basal contractility of the papillary muscle was 0.27 ± 0.03 mN at 10 V, 500-ms pulse duration, and 1 Hz. From 0.1 to 1.0 Hz, contractility decreased with an increase in frequency (0.45 ± 0.11-0.10 ± 0.02 mN). The voltage-initiated muscle contractility varied from 3 to 6 V, and the contractility gradually increased as the voltage increased from 6 to 10 V (0.14 ± 0.02-0.28 ± 0.03 mN). Moreover, the muscle contractility increased when the calcium concentration was increased from 1.5 to 3 mM (0.45 ± 0.17-1.11 ± 0.05 mN); however, the contractility stopped increasing even when the concentration was increased to 7.5 mM (1.02 ± 0.23 mN).
CONCLUSIONS
Our method guaranteed the survivability of papillary muscle ex vivo and provided instructions for Myostation-Intact users for isolated muscle contractility investigations.
Topics: Mice; Animals; Papillary Muscles; Myocardial Contraction
PubMed: 36168142
DOI: 10.1002/ame2.12272 -
Journal of the Mechanical Behavior of... Nov 2020The mitral valve (MV) apparatus is a complex mechanical structure including annulus, valve leaflets, papillary muscles (PMs) and connected chordae tendineae. Chordae...
The mitral valve (MV) apparatus is a complex mechanical structure including annulus, valve leaflets, papillary muscles (PMs) and connected chordae tendineae. Chordae anchor to the papillary muscles to help the valve open and close properly during one cardiac cycle. It is of paramount importance to understand the functional, mechanical, and microstructural properties of mitral valve chordae and connecting PMs. In particular, little is known about the biomechanical properties of the anterior and posterior papillary muscle and corresponding chords. In this work, we performed uniaxial and biaxial tensile tests on the anterolateral (APM) and posteromedial papillary muscle (PPM), and their respective corresponding chordae tendineae, chordae and chordae, in porcine hearts. Histology was carried out to link the microstructure and macro-mechanical behavior of the chordae and PMs. Our results demonstrate that chordae are less in number, but significantly longer and stiffer than chordae. These different biomechanical properties may be partially explained by the higher collagen core ratio and larger collagen fibril density of chordae No significant mechanical or microstructural differences were observed along the circumferential and longitudinal directions of APM and PPM samples. Data measured on chordae and PMs were further fitted with the Ogden and reduced Holzapfel - Ogden strain energy functions, respectively. This study presents the first comparative anatomical, mechanical, and structural dataset of porcine mitral valve chordae and related PMs. Results indicate that a PM based classification of chordae will need to be considered in the analysis of the MV function or planning a surgical treatment, which will also help developing more precise computational models of MV.
Topics: Animals; Chordae Tendineae; Collagen; Mitral Valve; Mitral Valve Insufficiency; Papillary Muscles; Swine
PubMed: 32835989
DOI: 10.1016/j.jmbbm.2020.104011 -
BMC Cardiovascular Disorders Aug 2023Fabry disease (FD) is an X-linked genetic lysosomal disease, in which a deficit in the alpha-galactosidase A enzyme results in lysosomal build-up of...
BACKGROUND AND AIMS
Fabry disease (FD) is an X-linked genetic lysosomal disease, in which a deficit in the alpha-galactosidase A enzyme results in lysosomal build-up of globotriaosylceramide in several organs, causing cardiac, renal and cerebrovascular complications. The aim of this study was to assess the prevalence of papillary muscle hypertrophy (PMH) in patients with FD.
METHODS
A group of 63 patients with FD and a positive genetic diagnosis were studied and were divided into two groups: one included 24 patients with FD and LVH and another group included 39 patients with FD and without LVH. Papillary muscles were measured from the left parasternal short axis view, defining PMH as a diastolic thickness greater than 11 mm in any diameter.
RESULTS
Patients with FD and LVH had a high prevalence of anterolateral PMH (66.6%), and such prevalence was lower for the posteromedial PMH (33.3%). However, patients who had not yet developed LVH had a high prevalence of anterolateral PMH (33.3%).
CONCLUSIONS
Patients with FD in the pre-clinical stage (without LVH) have a high prevalence of PMH, especially involving the anterolateral papillary muscle. This finding could be an early marker for the development of LVH, allowing to suspect the disease during its early stages, and begin enzyme replacement therapy in the appropriate patients.
Topics: Humans; Fabry Disease; Papillary Muscles; Prevalence; Hypertrophy; Kidney
PubMed: 37635225
DOI: 10.1186/s12872-023-03463-w -
JACC. Cardiovascular Imaging Sep 2019This study sought to define interpapillary muscle dyssynchrony as a major contributing factor in functional mitral regurgitation (FMR) and prove the reversibility of FMR... (Observational Study)
Observational Study
OBJECTIVES
This study sought to define interpapillary muscle dyssynchrony as a major contributing factor in functional mitral regurgitation (FMR) and prove the reversibility of FMR by interpapillary muscle resynchronization.
BACKGROUND
Mechanistic features of FMR include papillary muscle displacement due to left ventricular remodeling. Intraventricular conduction delay might further augment this condition by introducing interpapillary muscle dyssynchrony.
METHODS
We enrolled 269 chronic heart failure with reduced ejection fraction patients with conduction delay and comprehensively assessed dyssynchrony by complementary echocardiographic techniques covering the entire spectrum of dyssynchrony.
RESULTS
Patients with severe FMR had markedly increased interpapillary longitudinal dyssynchrony (160 ms [interquartile range (IQR): 120 to 200 ms]) compared with those with moderate (70 ms [IQR: 40 to 110 ms]), no, or mild FMR (60 ms [IQR: 30 to 100 ms]; p < 0.001). Increased interpapillary muscle dyssynchrony was correlated with regurgitant volume (r = 0.50; p < 0.001) and vena contracta width (r = 0.49; p < 0.001). Restoration of longitudinal papillary muscle synchronicity by cardiac resynchronization therapy was correlated with FMR regression, as reflected by the reduction in regurgitant volume (r = 0.46; p < 0.001) and vena contracta width (r = 0.58; p < 0.001). Conversely, the improvement of FMR was associated with improved interpapillary radial (p = 0.006) and longitudinal (p < 0.001) dyssynchrony. The improvement of dyssynchrony-mediated FMR signified a better prognosis compared with no improvement in FMR during the 8-year follow-up period even after comprehensive adjustment by a bootstrap-selected confounder model (adjusted hazard ratio: 0.41; 95% confidence interval: 0.18 to 0.91; p = 0.028). The results remained virtually unchanged after adjustment for left bundle branch block.
CONCLUSIONS
Intraventricular dyssynchrony introduces unequal contraction by papillary muscle bearing walls, which has an adverse effect on FMR. Cardiac resynchronization therapy can effectively restore interpapillary balance and thus create a less tented leaflet configuration, resulting in a clinically meaningful reduction of FMR. The restoration of papillary muscle synchronicity in dyssynchrony-mediated FMR translates into a significantly better prognosis.
Topics: Aged; Cardiac Resynchronization Therapy; Chronic Disease; Female; Heart Failure; Humans; Male; Middle Aged; Mitral Valve; Mitral Valve Insufficiency; Myocardial Contraction; Papillary Muscles; Recovery of Function; Stroke Volume; Treatment Outcome; Ventricular Dysfunction, Left; Ventricular Function, Left; Ventricular Remodeling
PubMed: 30121264
DOI: 10.1016/j.jcmg.2018.06.013 -
JTCVS Open Sep 2021
PubMed: 36003741
DOI: 10.1016/j.xjon.2021.05.007 -
Polski Merkuriusz Lekarski : Organ... Oct 2020Mitral valve prolapse (MVP) is diagnosed by auscultation and echocardiography in about 2-3% of the general population and takes rather a benign course. However, in some...
UNLABELLED
Mitral valve prolapse (MVP) is diagnosed by auscultation and echocardiography in about 2-3% of the general population and takes rather a benign course. However, in some patients, ventricular arrhythmia and sudden cardiac death (SCD) occur, which is linked to mitral annular disjunction (MAD). MAD is defined as distinct separation of the mitral valve annulus-left atrial wall continuum and the basal region of the posterolateral left ventricular (LV) myocardium. MAD results in disturbed inferior-posterior LV wall and posteromedial papillary muscle stretch giving rise to local fibrosis presenting in cardiac magnetic resonance (CMR) as late gadolinium enhancement (LGE) and posing a substrate for malignant arrhythmia. Multidetector-row computed tomography (MDCT) in MAD patients is still rarely used.
A CASE REPORT
Mitral valve prolapse (MVP) is diagnosed by auscultation and echocardiography in about 2-3% of the general population and takes rather a benign course. However, in some patients, ventricular arrhythmia and sudden cardiac death (SCD) occur, which is linked to mitral annular disjunction (MAD). MAD is defined as distinct separation of the mitral valve annulus-left atrial wall continuum and the basal region of the posterolateral left ventricular (LV) myocardium. MAD results in disturbed inferior-posterior LV wall and posteromedial papillary muscle stretch giving rise to local fibrosis presenting in cardiac magnetic resonance (CMR) as late gadolinium enhancement (LGE) and posing a substrate for malignant arrhythmia. Multidetector-row computed tomography (MDCT) in MAD patients is still rarely used.
Topics: Contrast Media; Gadolinium; Humans; Mitral Valve; Mitral Valve Prolapse; Papillary Muscles
PubMed: 33130794
DOI: No ID Found -
JTCVS Open Sep 2021Undersizing mitral annuloplasty (UMA) to repair functional mitral regurgitation lacks durability, as it forces leaflet coaptation without relieving the sub-leaflet...
BACKGROUND
Undersizing mitral annuloplasty (UMA) to repair functional mitral regurgitation lacks durability, as it forces leaflet coaptation without relieving the sub-leaflet tethering forces. In this biomechanical study, we demonstrate that papillary muscle approximation (PMA) prior to UMA can drastically relieve tethering forces and improve valve function, without the need for significant annular downsizing.
METHODS
An model of functional mitral regurgitation (FMR) was used, in which pig mitral valves were geometrically perturbed to induce FMR, and the repairs were performed. Nine pig mitral valves were studied as follows: normal(baseline), functional mitral regurgitation (FMR), true-sized annuloplasty to 30mm (TSR), and undersized annuloplasty to 26mm (DSR); and concomitant papillary muscle approximation (PMA) at both ring sizes. Mitral regurgitation, valve kinematics, and chordal forces were measured and compared between groups.
RESULTS
FMR geometry induced a 16.31±7.33% regurgitant fraction, compared to none at baseline. 30mm/TSR reduced regurgitation to 6.05±5.63% and a 26mm/DSR to 5.06±6.76%. Addition of papillary muscle approximation prior to either rings, reduced regurgitation to 3.87±6.79% with the true sized ring (TSR+PMA), and 3.71±6.25% with the downsized ring (DSR+PMA). Peak anterior and posterior marginal chordal forces were elevated to 0.09±0.1N and 0.12±0.1N respectively with FMR, which were not reduced by annuloplasty of either sizes. Addition of PMA, reduced the forces significantly to 0.23±0.02N and 0.51±0.04N.
CONCLUSION
This biomechanical study, demonstrates that papillary muscle approximation relieves tethering forces and when added to annuloplasty, and mobilizes the leaflets to achieve a good valve closure. Such a result could be achieved without the need for extensive annular downsizing.
PubMed: 35299626
DOI: 10.1016/j.xjon.2021.04.008