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The Journal of Thoracic and... Oct 2022New transapical minimally invasive artificial chordae implantation devices are a promising alternative to traditional open-heart repair, with the potential for decreased...
OBJECTIVE
New transapical minimally invasive artificial chordae implantation devices are a promising alternative to traditional open-heart repair, with the potential for decreased postoperative morbidity and reduced recovery time. However, these devices can place increased stress on the artificial chordae. We designed an artificial papillary muscle to alleviate artificial chordae stresses and thus increase repair durability.
METHODS
The artificial papillary muscle device is a narrow elastic column with an inner core that can be implanted during the minimally invasive transapical procedure via the same ventricular incision site. The device was 3-dimensionally printed in biocompatible silicone for this study. To test efficacy, porcine mitral valves (n = 6) were mounted in a heart simulator, and isolated regurgitation was induced. Each valve was repaired with a polytetrafluoroethylene suture with apical anchoring followed by artificial papillary muscle anchoring. In each case, a high-resolution Fiber Bragg Grating sensor recorded forces on the suture.
RESULTS
Hemodynamic data confirmed that both repairs-with and without the artificial papillary muscle device-were successful in eliminating mitral regurgitation. Both the peak artificial chordae force and the rate of change of force at the onset of systole were significantly lower with the device compared with apical anchoring without the device (P < .001 and P < .001, respectively).
CONCLUSIONS
Our novel artificial papillary muscle could integrate with minimally invasive repairs to shorten the artificial chordae and behave as an elastic damper, thus reducing sharp increases in force. With our device, we have the potential to improve the durability of off-pump transapical mitral valve repair procedures.
Topics: Animals; Chordae Tendineae; Heart Valve Prosthesis Implantation; Mitral Valve; Mitral Valve Insufficiency; Papillary Muscles; Polytetrafluoroethylene; Silicones; Swine
PubMed: 33451843
DOI: 10.1016/j.jtcvs.2020.11.105 -
Journal of Cardiac Surgery Mar 2020The main pathophysiological factor of chronic ischemic mitral regurgitation (MR) is the outward displacement of the papillary muscles (PMs) leading to leaflet tethering.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIMS
The main pathophysiological factor of chronic ischemic mitral regurgitation (MR) is the outward displacement of the papillary muscles (PMs) leading to leaflet tethering. For this reason, papillary muscle intervention (PMI) in combination with mitral ring annuloplasty (MRA) has recently been introduced into clinical practice to correct this displacement, and to reduce the recurrence of regurgitation.
METHODS
A meta-analysis was conducted comparing the outcomes of PMI and MRA performed in combination vs MRA performed alone, in terms of MR recurrence and left ventricular reverse remodeling (LVRR). A meta-regression was carried out to investigate the impact of the type of PMI procedure on the outcomes.
RESULTS
MR recurrence in patients undergoing both PMI and MRA was lower than in those who only had MRA (log incidence rate ratio, -0.66; lower-upper limits, -1.13 to 0.20; I = 0.0%; p = .44; Egger's test: intercept 0.35 [-0.78 to 1.51]; p = .42). The group with both PMI and MRA and that with only MRA showed a slightly higher reduction in left ventricular diameters (-5.94%; -8.75% to 3.13%,). However, in both groups, LVRR was <10%. No difference was detected between PM relocation/repositioning and papillary muscle approximation in terms of LVRR (p = .33).
CONCLUSIONS
Using PMI and MRA together has a lower MR recurrence than using MRA alone. No significant LVRR was observed between the two groups nor between the PMI techniques employed.
Topics: Aged; Female; Humans; Male; Middle Aged; Mitral Valve Annuloplasty; Mitral Valve Insufficiency; Papillary Muscles; Recurrence; Secondary Prevention; Ventricular Remodeling
PubMed: 31951676
DOI: 10.1111/jocs.14407 -
Medicine Nov 2023Deciding whether to include or exclude the papillary muscles and trabeculae to blood pool is essential, because quantifications of left ventricular (LV) functional...
Deciding whether to include or exclude the papillary muscles and trabeculae to blood pool is essential, because quantifications of left ventricular (LV) functional parameters and myocardial mass are significantly affected. As a result, such inclusion or exclusion might produce different indices for diagnosis and therapy. Using cardiac computed tomography (CT), we obtained standard values of the portion of papillary muscle and trabeculae in normal adults, and to find out how the inclusion or exclusion of papillary muscle and trabeculae affect LV functional parameters depending on the patient group. Excluding the papillary muscles from the LV mass results in easier automated contour detection using CT. The percentage portions of papillary muscle and trabeculae to LV end-diastolic volume (EDV) and LV mass (LVM) were 11.9 ± 5.6% and 20.2 ± 4.3%, respectively, significantly affecting disease diagnosis. Imaging should be consistent at follow-up and include or exclude the papillary muscles and trabeculae to avoid introducing significant differences between measurements.
Topics: Adult; Humans; Papillary Muscles; Ventricular Function, Left; Cross-Sectional Studies; Heart Ventricles; Tomography, X-Ray Computed; Stroke Volume; Reproducibility of Results
PubMed: 37986395
DOI: 10.1097/MD.0000000000036106 -
Journal of Clinical Medicine Feb 2022Sudden cardiac death (SCD) from ventricular fibrillation (VF) can occur in mitral valve prolapse (MVP) in the absence of other comorbidities including mitral... (Review)
Review
Sudden cardiac death (SCD) from ventricular fibrillation (VF) can occur in mitral valve prolapse (MVP) in the absence of other comorbidities including mitral regurgitation, heart failure or coronary disease. Although only a small proportion with MVP are at risk, it can affect young, otherwise healthy adults, most commonly premenopausal women, often as the first presentation of MVP. In this review, we discuss arrhythmic mechanisms in MVP and mechanistic approaches for sudden death risk assessment and prevention. We define arrhythmogenic or arrhythmic MVP (AMVP) as MVP associated with complex and frequent ventricular ectopy, and malignant MVP (MMVP) as MVP with high risk of SCD. Factors predisposing to AMVP are myxomatous, bileaflet MVP and mitral annular disjunction (MAD). Data from autopsy, cardiac imaging and electrophysiological studies suggest that ectopy in AMVP is due to inflammation, fibrosis and scarring within the left ventricular (LV) base, LV papillary muscles and Purkinje tissue. Postulated mechanisms include repetitive injury to these regions from systolic papillary muscle stretch and abrupt mitral annular dysmotility (excursion and curling) and diastolic endocardial interaction of redundant mitral leaflets and chordae. Whereas AMVP is seen relatively commonly (up to 30%) in those with MVP, MVP-related SCD is rare (2-4%). However, the proportion at risk (i.e., with MMVP) is unknown. The clustering of cardiac morphological and electrophysiological characteristics similar to AMVP in otherwise idiopathic SCD suggests that MMVP arises when specific arrhythmia modulators allow for VF initiation and perpetuation through action potential prolongation, repolarization heterogeneity and Purkinje triggering. Adequately powered prospective studies are needed to assess strategies for identifying MMVP and the primary prevention of SCD, including ICD implantation, sympathetic modulation and early surgical mitral valve repair. Given the low event rate, a collaborative multicenter approach is essential.
PubMed: 35268384
DOI: 10.3390/jcm11051285 -
Journal of Forensic Sciences Jan 2023Anomalous papillary muscle (APM) insertion into the anterior mitral valve leaflet is often associated with hypertrophic cardiomyopathy (HCM) but is reported in other...
Anomalous papillary muscle (APM) insertion into the anterior mitral valve leaflet is often associated with hypertrophic cardiomyopathy (HCM) but is reported in other cases as a rare finding. Mere presence does not strictly imply hemodynamic disturbance, and several types exist, with various impacts on left ventricular outflow tract (LVOT) obstruction. The interpretation of isolated anomaly is challenging at autopsy because significant LVOT obstruction is dynamic. We analyzed autopsy cases with APM regarding the site of PM insertion and origin, number of PM bellies, anomalous insertions, heart weight, left ventricle (LV) thickness, LV endocardial fibrosis, subjects' age, sex, cause, and manner of death. A total of 20 cases were identified. Fourteen were identified incidentally, while in 670 systematically examined hearts, the APM was identified in six cases, indicating a prevalence of 0.9%. In eight cases, the manner of death was natural (one case with HCM), and in 12 non-natural. Type II anomaly of PM was most frequent (n = 8), followed by Type III (n = 7) and Type I (n = 5). Subjects who died of natural causes were significantly older and had heavier hearts (median 455 g vs. 330 g; p < 0.05) without difference in LV thickness (median 16 mm vs. 15 mm; p > 0.05). Histology performed in four cases showed a pattern of direct insertion of cardiomyocytes into the leaflet's thick fibrous tissue with a narrow overlapping zone. The APM is rare, can be easily overlooked, and does not imply significant pathology per se. We discussed proper assessment of the significance of this anomaly at autopsy.
Topics: Humans; Mitral Valve; Papillary Muscles; Autopsy; Heart Ventricles; Cardiomyopathy, Hypertrophic
PubMed: 36480239
DOI: 10.1111/1556-4029.15182 -
ASAIO Journal (American Society For... Aug 2021Papillary muscle rupture (PMR) or chordae tendinae rupture (CTR) is a rare but lethal complication after ST elevation myocardial infarction (STEMI). Due to the rarity of...
Papillary muscle rupture (PMR) or chordae tendinae rupture (CTR) is a rare but lethal complication after ST elevation myocardial infarction (STEMI). Due to the rarity of this condition, there are limited studies defining its epidemiology and outcomes. This is a retrospective study from Nationwide Inpatient Sample database from 2002 to 2014 of patients with STEMI and PMR/CTR. Outcomes of interest were incidence of in-hospital mortality, cardiogenic shock (CS), utilization of mechanical circulatory support (MCS) devices and mitral valve procedures (MVPs) among patients with and without rupture. We also performed simulation using the cardiovascular model to better understand the hemodynamics of severe mitral regurgitation and effects of different medications and device therapy. We identified 1,888 patients with STEMI complicated with PMR/CTR. Most of the patients were >65 years of age (65.3%), male (63.6%), and white (82.3%). They had significantly higher incidence of CS, cardiac arrest, and utilization of MCS devices. In-hospital mortality was higher in patients with rupture (41% vs. 7.40%, p < 0.001) which remained unchanged over the study period. Hospitalization cost and length of stay was also higher in them. MVP and revascularization led to better survival rates (27.9% vs. 60.6%, adjusted OR: 0.14; 95% CI: 0.10-0.19; p < 0.001). Despite significant advancement in the revascularization strategy, PMR/CTR after STEMI continues to portend poor prognosis with high inpatient mortality. Cardiogenic shock is a common presentation and is associated with significantly inpatient mortality. Future studies are needed determine the best strategies to improve outcomes in patients with STEMI with PMR/CTR and CS.
Topics: Aged; Female; Hospital Mortality; Humans; Male; Papillary Muscles; Retrospective Studies; ST Elevation Myocardial Infarction; Shock, Cardiogenic
PubMed: 33093383
DOI: 10.1097/MAT.0000000000001299 -
The Journal of Thoracic and... Dec 2023Isolated tricuspid ring annuloplasty remains the surgical standard for functional tricuspid regurgitation repair but offers suboptimal results when right ventricular...
OBJECTIVE
Isolated 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.
METHODS
Functional 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.
RESULTS
With 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.
CONCLUSIONS
Papillary 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.
Topics: Sheep; Animals; Tricuspid Valve Insufficiency; Papillary Muscles; Tricuspid Valve; Heart Ventricles; Hemodynamics
PubMed: 37330209
DOI: 10.1016/j.jtcvs.2023.05.039 -
Circulation. Cardiovascular Imaging Apr 2023The relation between ventricular arrhythmia and fibrosis in mitral valve prolapse (MVP) is reported, but underlying valve-induced mechanisms remain unknown. We evaluated...
BACKGROUND
The relation between ventricular arrhythmia and fibrosis in mitral valve prolapse (MVP) is reported, but underlying valve-induced mechanisms remain unknown. We evaluated the association between abnormal MVP-related mechanics and myocardial fibrosis, and their association with arrhythmia.
METHODS
We studied 113 patients with MVP with both echocardiogram and gadolinium cardiac magnetic resonance imaging for myocardial fibrosis. Two-dimensional and speckle-tracking echocardiography evaluated mitral regurgitation, superior leaflet and papillary muscle displacement with associated exaggerated basal myocardial systolic curling, and myocardial longitudinal strain. Follow-up assessed arrhythmic events (nonsustained or sustained ventricular tachycardia or ventricular fibrillation).
RESULTS
Myocardial fibrosis was observed in 43 patients with MVP, predominantly in the basal-midventricular inferior-lateral wall and papillary muscles. Patients with MVP with fibrosis had greater mitral regurgitation, prolapse, and superior papillary muscle displacement with basal curling and more impaired inferior-posterior basal strain than those without fibrosis (<0.001). An abnormal strain pattern with distinct peaks pre-end-systole and post-end-systole in inferior-lateral wall was frequent in patients with fibrosis (81 versus 26%, <0.001) but absent in patients without MVP with basal inferior-lateral wall fibrosis (n=20). During median follow-up of 1008 days, 36 of 87 patients with MVP with >6-month follow-up developed ventricular arrhythmias associated (univariable) with fibrosis, greater prolapse, mitral annular disjunction, and double-peak strain. In multivariable analysis, double-peak strain showed incremental risk of arrhythmia over fibrosis.
CONCLUSIONS
Basal inferior-posterior myocardial fibrosis in MVP is associated with abnormal MVP-related myocardial mechanics, which are potentially associated with ventricular arrhythmia. These associations suggest pathophysiological links between MVP-related mechanical abnormalities and myocardial fibrosis, which also may relate to ventricular arrhythmia and offer potential imaging markers of increased arrhythmic risk.
Topics: Humans; Mitral Valve Prolapse; Mitral Valve Insufficiency; Arrhythmias, Cardiac; Papillary Muscles; Fibrosis; Prolapse
PubMed: 37071717
DOI: 10.1161/CIRCIMAGING.122.014963 -
Morphologie : Bulletin de L'Association... Sep 2023To review the morphology of papillary muscles in both the ventricles of heart. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To review the morphology of papillary muscles in both the ventricles of heart.
METHODS
The articles were collected from databases such as MEDLINE etc. using Google as the search engine. Keywords used were papillary muscle morphology, papillary muscle dimensions, papillary muscle blood supply, papillary muscle histology, papillary muscle development and papillary muscle biomechanical properties. Studies were included if they assessed the aforesaid features of papillary muscles. Thirty-four studies were included in the review. Meta-analysis was done for number of right and left ventricular papillary muscles and dimensions of right ventricular papillary muscles. The data obtained from these studies was synthesized, pooled and all analyses were performed using R Statistical Software (v4.1.2; R Core Team 2021) with R package meta version 5.5-0.
RESULTS
Marked difference existed between papillary muscles of right and left ventricles. In right ventricle, one anterior (76%), one posterior (38%) and one septal (30%) papillary muscle were most common. In left ventricle, one anterior (46%) and two posterior papillary muscles (26%) were most common. In both the ventricles, commonly observed gross appearances of papillary muscles were conical and flat-topped. Papillary muscles were lengthier in left ventricle than right ventricle. Anterior papillary muscle was 1.36cm long, 1.36cm broad and 0.64cm thick in right ventricle. It was the largest in both right and left ventricles.
CONCLUSION
The morphology and measurements of papillary muscles vary significantly. Thorough knowledge of these variations will help surgeons to determine appropriate surgical repair procedures for the valve and subvalvular apparatus.
Topics: Heart Ventricles; Papillary Muscles
PubMed: 36732176
DOI: 10.1016/j.morpho.2023.01.002 -
Journal of Cardiovascular Translational... Jun 2023Ventricular tachycardia associated with papillary muscle (PM) is often refractory to standard radiofrequency ablation (RFA). The needle-tipped ablation catheter (NT-AC)...
Ventricular tachycardia associated with papillary muscle (PM) is often refractory to standard radiofrequency ablation (RFA). The needle-tipped ablation catheter (NT-AC) has been used to treat deep intramyocardial substrates, but its use for PM has not been characterized. Using an ex vivo experimental platform, both 3 mm and 6 mm NT-AC created larger ablation lesion volumes and depths than open-irrigated ablation catheter did (OI-AC; e.g., 57.12 ± 9.70mm and 2.42 ± 0.22 mm, respectively; p < 0.01 for all comparisons). Longer NT-AC extension (6 mm) resulted in greater ablation lesion volumes and maximum depths (e.g., 333.14 ± 29.13mm and 6.46 ± 0.29 mm, respectively, compared to the shorter 3 mm NT-AC extension, 143.33 ± 12.77mm, and 4.46 ± 0.14 mm; both p < 0.001). There were no steam pops. In conclusion, for PM ablation, the NT-AC was able to achieve ablation lesions that were larger and deeper than with conventional OI-AC. Ablation of PM may be another application for needle-tip ablation. Further studies are warranted to establish long-term safety and efficacy in human studies.
Topics: Humans; Papillary Muscles; Therapeutic Irrigation; Equipment Design; Catheters; Catheter Ablation
PubMed: 36264437
DOI: 10.1007/s12265-022-10331-z