Papillary Muscle Morphology Research Articles

Cardiac Computed Tomography Assessment of the Variation of Papillary Muscle Morphology before Mitral Valve Surgery

Background. The morphology of the papillary muscles of the left ventricle is highly variable. Few studies have investigated papillary muscle morphology using imaging. Objective. This study aimed to assess papillary muscle morphology with primary mitral regurgitation (MR) using cardiac computed tomography (CT). Methods. We examined 116 patients who underwent robotic mitral valve repair for primary MR using preoperative cardiac CT. Papillary muscle morphology was assessed using CT images and compared with operative findings. Results. CT images of papillary muscles were consistent with the operative findings during robotic mitral valve repair in all cases. Both the anterolateral papillary muscle (APM) and posteromedial papillary muscle (PPM) groups were identified in all cases, and the middle papillary muscle (MPM) group was identified in 24.1% of cases. The PPM group had a higher proportion of complex morphologies with more heads and bases than the APM group (head: p<0.001 and base: p<0.001). The PPM group had smaller papillary muscle sizes than the APM group. The MPM group in most patients had one base and one head (78.6%). Papillary muscle sizes were significantly smaller in the order of the APM, PPM, and MPM groups (p<0.001). Conclusions. Cardiac CT allowed clear visualization and accurate assessment of papillary muscle morphology in the left ventricle. It may be useful to obtain the papillary muscle variations preoperatively using CT imaging in procedures involving the papillary muscles such as mitral valve repair.

Predictors of moderate to severe ischemic mitral regurgitation after myocardial infarction: a cardiac magnetic resonance study.

The purpose of this study is to explore the predictors of moderate to severe ischemic mitral regurgitation (IMR) after myocardial infarction with cardiovascular magnetic resonance (CMR). From January 2016 to September 2018, 109 patients (mean age 60 ± 8years) with IMR were studied retrospectively. All patients underwent CMR-cine with True-FISP sequence and late gadolinium enhancement (LGE) with a phase-sensitive inversion recovery sequence. The presence of papillary muscle infarction (PMI), global left ventricular (LV) infarcted extent, LV functional parameters, and LV myocardial strain were assessed. Univariate and multivariate analyses were performed to identify factors in the development of moderate to severe IMR. Mild IMR was present in 61 patients (56%), and moderate to severe IMR was present in 48 patients (44%). PMI was identified in 22 patients (20.1%); 14 of them (63.63%) showed a moderate or severe IMR. Global LV infarcted extent was increased in patients with moderate to severe IMR (p< 0.001). LV functional parameters of patients with moderate to severe IMR were statistically different from those of the patients with mild IMR (all p< 0.001), except the LV SV index (p= 0.142) and LV CI (p= 0.447). The global longitudinal strain (GLS), regional radial strain (RS), and circumferential strain (CS) of the moderate-to-severe IMR group were significantly decreased compared with those of the mild IMR group (p< 0.05). In multivariable analyses, age (OR = 1.11; p= 0.001), global LV infarct extent (OR = 1.14; p= 0.000), and GLS (OR = 1.31; p= 0.000) were associated with moderate-to-severe chronic IMR. The incidence of PMI was higher in patients with moderate-to-severe IMR. The extent of global LV infarcted extent and GLS were independent predictors of moderate-to-severe IMR. • Cardiovascular magnetic resonance late gadolinium enhancement and feature-tracking imaging provide reliable information on LV function, myocardial viability, and papillary muscle morphology. • Papillary muscle infarction is not an independent predictor of moderate-to-severe IMR. • The extent of global LV infarction and LV global longitudinal strain were independent predictors of moderate-to-severe chronic IMR.

Three-dimensional echocardiography for the assessment of left ventricular geometry and papillary muscle morphology in hypertrophic cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HC) is characterized by left ventricular (LV) hypertrophy and associated with papillary muscle (PM) abnormalities. The aim of this study was to evaluate the utility of three-dimensional echocardiography (3DE) for the geometric assessment of LV hypertrophy and PM morphology.MethodsThe study included 24 patients with an established diagnosis of HC and 31 healthy controls. 3DE was performed using an iE33 or EPIQ 7C ultrasound system with an X5-1 transducer. QLAB software was used for the 3D analysis of LV wall thickness (LVWT) and PM morphology and hypertrophy; the number and cross-sectional area (CSA) of anterolateral and posteromedial PMs; and the presence of bifid or accessory PMs.ResultsPatients with HC had a larger LVWT compared to controls in all segments (p < 0.001), and LVWT was largest in the midventricular septal segment (2.12 ± 0.68 cm). The maximum LVWT followed a spiral pattern from the LV base to the apex. The CSA of both anterolateral and posteromedial PMs was larger in patients with HC than in controls (1.92 vs. 1.15 cm2; p = 0.001 and 1.46 vs. 1.08 cm2; p = 0.033, respectively). The CSA of the posteromedial PM was larger in patients with LVOT obstruction than in those without (2.64 vs 1.16 cm2, p = 0.021).Conclusions3DE allows the assessment of LV geometry and PM abnormalities in patients with HC. 3DE demonstrated that the maximum hypertrophy was variable and generally located in a spiral from the LV base to the apex.

Morphological three-dimensional analysis of papillary muscles in borderline left ventricles.

Mitral valve anatomy has a significant impact on potential surgical options for patients with hypoplastic or borderline left ventricle. Papillary muscle morphology is a major component regarding this aspect. The purpose of this study was to use cardiac magnetic resonance to describe the differences in papillary muscle anatomy between normal, borderline, and hypoplastic left ventricles. We carried out a retrospective, observational cardiac magnetic resonance study of children (median age 5.36 years) with normal (n=30), borderline (n=22), or hypoplastic (n=13) left ventricles. Borderline and hypoplastic cases had undergone an initial hybrid procedure. Morphological features of the papillary muscles, location, and arrangement were analysed and compared across groups. All normal ventricles had two papillary muscles with narrow pedicles; however, 18% of borderline and 46% of hypoplastic cases had a single papillary muscle, usually the inferomedial type. In addition, in borderline or hypoplastic ventricles, the supporting pedicle occasionally displayed a wide insertion along the ventricular wall. The length ratio of the superolateral support was significantly different between groups (normal: 0.46±0.08; borderline: 0.39±0.07; hypoplastic: 0.36±0.1; p=0.009). No significant difference, however, was found when analysing the inferomedial type (0.42±0.09; 0.38±0.07; 0.39±0.22, p=0.39). The angle subtended between supports was also similar among groups (113°±17°; 111°±51° and 114°±57°; p=0.99). A total of eight children with borderline left ventricle underwent biventricular repair. There were no significant differentiating features for papillary muscle morphology in this subgroup. The superolateral support can be shorter or absent in borderline or hypoplastic left ventricle cases. The papillary muscle pedicles in these patients often show a broad insertion. These changes have important implications on surgical options and should be described routinely.

Hypertrophic cardiomyopathy: still connecting the dots between genotype and phenotype.

The current era of cardiac magnetic resonance (CMR) imaging has resulted in a resurgence of interest in hypertrophic cardiomyopathy (HCM). We are now much more aware of the various phenotypic expressions of this disease, which can manifest with typical septal thickening or other variants of hypertrophy, such as apical, midwall or concentric. Additionally, CMR has enabled us to appreciate the wide variety of abnormalities in papillary muscle morphology, which in some cases can contribute to left ventricular outflow tract or mid-cavitary level obstruction (1). In some subjects, mitral valve elongation, myocardial crypts, prominent apical trabeculation, papillary muscle thickening (with or without apical displacement) and abnormal chordal attachments may be subtle phenotypic HCM variants, despite normal left ventricular wall thickness. These abnormalities may be symptomatic to varying degrees or remain subclinical and be noted incidentally or on HCM familial screening programs. Whether these subjects will go on to develop progressive left ventricular hypertrophy (LVH) or whether they are manifesting incomplete phenotypic penetrance of the disease process remains unclear.

Morphology of papillary muscles in human adults: A cadaveric study

Introduction: The papillary muscles (PM) play an important role in ventricular overextension. The variability in the number, shape and location of papillary muscle of the right and the left ventricle is important for the surgeon in reparative procedures, papillary muscle dysfunction, mitral valve replacement and use of mitral valve homograft for mitral/tricuspid replacement. Materials and Methods: The study was conducted using 15 formalin fixed adult human hearts. The presence, number, shapes, length, number of additional heads of the papillary muscles were observed. The presence of moderator band (MB) was noted and its level of attachment to the anterior PM was observed. Results: Double anterior and posterior PM were found in few cases. The length of PM was longer in the left ventricle when compared to the right ventricle which was statistically significant. In the right ventricle cone-shaped PM was observed in the majority of the cases whereas flat topped PM was observed in 2 cases. In the left ventricle all the PM were cone shaped. In majority of the cases (N=13) the MB was attached to the lower third of the PM whereas in one case each it was attached to the upper third and to the middle third respectively. Conclusions: The morphology and morphometry of the papillary muscles of both ventricles and moderator band were defined. These may help cardiac surgeons during surgical procedures conducted for correction of their defects.

Modified surgical approach to symptomatic hypertrophic cardiomyopathy with abnormal papillary muscle morphology: Septal myectomy plus papillary muscle repositioning

Modified surgical approach to symptomatic hypertrophic cardiomyopathy with abnormal papillary muscle morphology: Septal myectomy plus papillary muscle repositioning

Characteristics and surgical outcomes of symptomatic patients with hypertrophic cardiomyopathy with abnormal papillary muscle morphology undergoing papillary muscle reorientation

In patients with hypertrophic cardiomyopathy with bifid hypermobile papillary muscles and a dynamic left ventricular outflow tract gradient, we performed surgical papillary muscle reorientation, fixing the mobile papillary muscle to the posterior left ventricle to reduce mobility. We report the outcomes of patients with hypertrophic cardiomyopathy undergoing surgical papillary muscle reorientation versus those of patients undergoing standard surgical procedures. We studied 204 consecutive patients with hypertrophic cardiomyopathy undergoing surgical intervention (after consensus decision) for symptomatic left ventricular outflow tract gradient. Preoperative and postoperative maximal (resting/provocable) left ventricular outflow tract gradients were recorded by using echocardiographic analysis. The population was divided into 3 groups: (1) isolated myectomy (n = 143; age, 54 +/- 14 years; 48% men), (2) myectomy plus mitral valve repair/replacement (n = 39; age, 54 +/- 13 years; 54% men), and (3) papillary muscle reorientation with or without myectomy (n = 22; age, 50 +/- 14 years; 59% men). The mean preoperative (103 +/- 32, 103 +/- 32, and 114 +/- 36 mm Hg; P = .3) and predischarge (15 +/- 18, 14 +/- 14, and 16 +/- 21 mm Hg; P = .9) maximal left ventricular outflow tract gradients were similar. There were no deaths either in the hospital or at 30 days. At a median follow-up of 166 days (interquartile range, 74-343 days), 21 of 22 patients in group 3 were asymptomatic. One patient in group 3 had a symptomatic left ventricular outflow tract gradient (87 mm Hg) requiring mitral valve replacement. In patients with hypertrophic cardiomyopathy with bifid hypermobile papillary muscles (even with a basal septal thickness <1.5 cm), papillary muscle reorientation reduces the symptomatic left ventricular outflow tract gradient. Long-term outcomes need to be ascertained.

Abnormal papillary muscle morphology is independently associated with increased left ventricular outflow tract obstruction in hypertrophic cardiomyopathy

Background:Abnormal papillary muscles (PM) are often found in hypertrophic cardiomyopathy (HCM).Objective:To assess the relationship between morphological alterations of PM in patients with HCM and left ventricular outflow tract (LVOT) obstruction,...

The comparative investigation of morphology of papillary muscles of left ventricle in different species

The papillary muscles of the heart are conical projections into the respective chamber of myocardium covered by endocardium. Functionally, the papillary muscles are important part of the respective valve complex. They prevent the cusps of a valve from being everted when the ventricle contracts. Our study was conducted on papillary muscles in left ventricle of 135 normal adult hearts (20 humans, 25 dogs, 60 sheep and 30 goats). The length (L), width (W), head number (HN), angle with ventricular wall (A degrees ), distance with annulus (AnD) and apex (ApD), and the shapes of the anterior and posterior papillary muscles were observed. The tendinous chords (CTN) attached to each papillary muscle were counted at their origin. The values of both anterior and posterior papillary muscles were not statistically significant (p > 0.05) in measurements of L, W, HN, A degrees and AnD of all species, but those of CTN and ApD were significant (p < 0.05) between human and animal hearts, while the difference was not significant (p > 0.05) between sheep and goat hearts. Knowledge of morphology of papillary muscles in different species will be of much use to clinical investigators in their studies.

Morphology of the atrioventricular valve in asplenia syndrome: A peculiar type of atrioventricular canal defect

The high risk of atrioventricular (AV) valve regurgitation is a major point of concern in the natural history of patients with atrioventricular canal defect (AVCD) and asplenia syndrome (AS). The morphology of the common AV valve in patients with AVCD and AS was therefore studied and compared with the anatomy of patients with AVCD but with atrial situs solitus. We compared the anatomic features of hearts with common AV valve (ventricular loop; AV valve alignment on ventricles; number of leaflets; number and morphology of papillary muscles and relationship of the bridging leaflets with the ventricular septum) in the hearts of 33 patients with AVCD and asplenia syndrome (Group 1) with those of 44 patients with common AV valve, complete AVCD, and atrial situs solitus (Group 2). Hearts featuring asplenia syndrome showed a significantly higher occurrence of anomalies of the ventricular loop ( p < .0001), right ventricular dominance ( p < .01), and a reduced number of valvular leaflets and papillary muscles ( p < .0005). On the contrary, hearts with situs solitus of the atria showed a significantly higher frequency of balanced ventricles ( p < .0001) and a common AV valve with five leaflets and five papillary muscles ( p < .000001). These data suggest that AVCDs in association with asplenia syndrome present morphologic peculiarities that may be considered as the substrate for the abnormal regurgitation. Recognizing the presence of these features could be of great value for the planning of a specific surgical treatment. These anatomic differences support the hypothesis of a genetic heterogeneity of AVCDs.

Papillary muscle morphology and function in left ventricular systolic dysfunction and dilated cardiomyopathy: A transesophageal echocardiographic study: Emest C. Madu, MD, Raju C. Reddy, MD, Ivan A. D'Cruz, MD, University of Tennessee and Veterans Affairs Medical Center, Memphis, TN

Papillary muscle morphology and function in left ventricular systolic dysfunction and dilated cardiomyopathy: A transesophageal echocardiographic study: Emest C. Madu, MD, Raju C. Reddy, MD, Ivan A. D'Cruz, MD, University of Tennessee and Veterans Affairs Medical Center, Memphis, TN

Eosinophils from hypereosinophilic patients damage endocardium of isolated feline heart muscle preparations.

Persistent eosinophilia in humans is often associated with endocardial damage to the heart, but a causal relation has not been established. We investigated the effect of eosinophils and eosinophil supernatants obtained from eight hypereosinophilic patients on the contractile performance and endocardial morphology of isolated, electrically stimulated cat papillary muscle preparations (n = 16). All these eosinophil suspensions contained high proportions of "hypodense" or "activated" cells. Eosinophils (5-15 x 10(6) ml organ bath) or eosinophil culture supernatants (prepared by overnight incubation at 37 degrees C) when added to papillary muscles produced acute changes in contractile behavior of these muscles identical to the previously reported effects of selective endocardial damage: a reduction in time to peak isometric twitch tension causing a reduction in peak isometric tension but with no significant reduction in rate of tension development or in maximum unloaded shortening velocity. All of these muscle preparations showed severely damaged endocardium at scanning electron microscopy. Addition of eosinophils from hypereosinophilic patients to muscles with selectively damaged endocardium (by previous transient [1-second] exposure to 1% Triton X-100) produced no further change in contractile performance. No significant change in contractile performance or endocardial morphology of papillary muscles (n = 16) was observed after addition of eosinophils (7.5-10 x 10(6] or neutrophils (8-15 x 10(6] from normal subjects or of cell-free culture medium. Thus, activated human eosinophils produce specific morphological and functional changes suggestive of specific damage to endocardium of isolated feline cardiac muscle.