Left ventricular bands (false tendons): echocardiographic and angiocardiographic delineation in children

Cardiac ventricular false tendons: A meta-analysis

Ventricular false tendons are fibromuscular structures that travel across the ventricular cavity. Left ventricular false tendons (LVFTs) have been examined through gross dissection and echocardiography. This study aimed to comprehensively evaluate the prevalence, morphology, and clinical importance of ventricular false tendons using a systematic review. In multiple studies, these structures have had a wide reported prevalence ranging from less than 1% to 100% of cases. This meta-analysis found the overall pooled prevalence of LVFTs to be 30.2%. Subgroup analysis indicated the prevalence to be 55.1% in cadaveric studies and 24.5% in living patients predominantly studied by echocardiography. Morphologically, left and right ventricular false tendons have been classified into several types based on their location and attachments. Studies have demonstrated false tendons have important clinical implications involving innocent murmurs, premature ventricular contractions, early repolarization, and impairment of systolic and diastolic function. Despite these potential complications, there is evidence demonstrating that the presence of false tendons can lead to positive clinical outcomes.

Three-dimensional echocardiographic assessment of Chiari’s network relationship with the left ventricular false tendon

Background

Left ventricular false tendon (LVFT) is a fibromuscular band crossing the left ventricular cavity. And Chiari’s network (CN) is a highly mobile, mesh-like, echogenic structure in right atrium. In this study, we aimed to evaluate the coexistence of LVFT in patients with CN. CN patients were examined with live/real-time three-dimensional transthoracic echocardiography (TTE) for visualization of LVFT.

Results

This is a single-center prospective study of 49 patients with CN. In literature studies, the average ratios of LVFT were 22% in the normal population. In our study, an increased ratio of LVFT (n = 31, 63.3%) was found in CN patients evaluated with a three-dimensional TTE (63.3% versus 22%) (p = 0.01). The interatrial septal aneurysm was found in 31 (63.3%) patients with CN. And, the positive contrast echocardiography examination was determined in 22 (61.1%) patients with CN.

Conclusions

Our study reveals that CN is associated with LVFT and is also associated with cardiac anomalies like an interatrial septal aneurysm, and atrial septal defect. And LVFT can be evaluated better with three-dimensional TTE than with traditional two-dimensional TTE. Patients with CN should be evaluated more carefully by three-dimensional echocardiography as they can be in synergy in terms of the cardiac pathologies they accompany.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43044-022-00287-5.

Left ventricular false tendons and electrocardiogram repolarization abnormalities in healthy young subjects

AIM

To describe echocardiographically left ventricular false tendon characteristics and the correlation with ventricular repolarization abnormalities in young athletes.

METHODS

Three hundred and sixteen healthy young athletes from different sport disciplines were evaluated from 2009 to 2011 during routine screening for agonistic sports eligibility. All subjects, as part of standard pre-participation screening medical evaluation, underwent a basal and post step test 12-lead electrocardiogram (ECG). The athletes with abnormal T-wave flattening and/or inversion were considered for an echocardiogram evaluation and an incremental maximal exercise test on a cycle ergometer. Arterial blood pressure and heart rate, during and after exercise, were also measured.

RESULTS

Twenty-one of the 316 subjects (6.9%) showed false tendons in the left ventricle. The majority of false tendons (52.38%) were localized between the middle segments of the inferior septum and the lateral wall, 19.06% between the distal segments of the septum and the lateral wall, in 5 subjects between the middle segments of the anterior and inferior walls, and in one subject between the middle segments of the anterior septum and the posterior wall. ECG abnormalities, represented by alterations of ventricular repolarization, were found in 11 subjects (52.38%), 90% of these anomalies were T wave abnormalities from V1 to V3. These anomalies disappeared with an increasing heart rate following the three minute step test as well as during the execution of the maximal exercise.

CONCLUSION

Left ventricular false tendons are frequently localized between the middle segments of the inferior septum and the lateral wall and are statistically associated with ventricular repolarization abnormalities.

Protective Role of False Tendon in Subjects with Left Bundle Branch Block: A Virtual Population Study

False tendons (FTs) are fibrous or fibromuscular bands that can be found in both the normal and abnormal human heart in various anatomical forms depending on their attachment points, tissue types, and geometrical properties. While FTs are widely considered to affect the function of the heart, their specific roles remain largely unclear and unexplored. In this paper, we present an in silico study of the ventricular activation time of the human heart in the presence of FTs. This study presents the first computational model of the human heart that includes a FT, Purkinje network, and papillary muscles. Based on this model, we perform simulations to investigate the effect of different types of FTs on hearts with the electrical conduction abnormality of a left bundle branch block (LBBB). We employ a virtual population of 70 human hearts derived from a statistical atlas, and run a total of 560 simulations to assess ventricular activation time with different FT configurations. The obtained results indicate that, in the presence of a LBBB, the FT reduces the total activation time that is abnormally augmented due to a branch block, to such an extent that surgical implant of cardiac resynchronisation devices might not be recommended by international guidelines. Specifically, the simulation results show that FTs reduce the QRS duration at least 10 ms in 80% of hearts, and up to 45 ms for FTs connecting to the ventricular free wall, suggesting a significant reduction of cardiovascular mortality risk. In further simulation studies we show the reduction in the QRS duration is more sensitive to the shape of the heart then the size of the heart or the exact location of the FT. Finally, the model suggests that FTs may contribute to reducing the activation time difference between the left and right ventricles from 12 ms to 4 ms. We conclude that FTs may provide an alternative conduction pathway that compensates for the propagation delay caused by the LBBB. Further investigation is needed to quantify the clinical impact of FTs on cardiovascular mortality risk.

Transverse false tendons in the left ventricular cavity are associated with early repolarization

BACKGROUND

Left ventricular false tendons (LVFTs) are related to precordial murmurs, ventricular arrhythmias and some repolarization abnormalities. Early repolarization (ER) is a specific type of repolarization abnormality.

OBJECTIVE

The aim of the present study was to investigate the relationship between LVFTs and ER.

METHODS

This study retrospectively included 99 consecutive healthy subjects and 33 patients with ER. Early repolarization was defined as an elevation of the QRS-ST junction of >0.1 mV from baseline in at least 2 inferior or lateral leads, manifested as QRS slurring or notching. Each participant was examined using echocardiography with second harmonic imaging, and the attachments of the LVFTs were recorded.

RESULTS

A total of 93 LVFTs were present in 82 (83%) of the 99 healthy subjects. Of these 93 LVFTs, the majority (79/93, or 84.9%) were longitudinal-type LVFTs, which originated from the basal interventricular septum (IVS) and progressed toward the apical segment of the left ventricular free wall. There were significant differences in the positioning of the LVFTs between the ER patients and control (P < 0.0001). LVFTs between mid-IVS to the middle of the LV free wall were found more common in patients with ER compared with control subjects (47.5% vs. 6.5%, P < 0.0001). In the ER group, LVFTs between the basal IVS to the apical segment of LV free wall were only identified in 21% of the LVFTs, compared to a value of 84.9% for the control group (P < 0.0001). The distribution of LVFT trends in the ER group was also significantly different from that in the control group (P < 0.05).

CONCLUSIONS

LVFTs are commonly visualized using echocardiography. An LVFT from the basal IVS to the apical segment of the left ventricular free wall may be a normal anatomical structure in the left ventricular cavity. On the contrary, transverse false tendons in the left ventricular cavity may be associated with ER.

Basic Study and Clinical Implications of Left Ventricular False Tendon. Is it Associated With Innocent Murmur in Children or Heart Disease?

INTRODUCTION AND OBJECTIVES

Left ventricular false tendon is a structure of unknown function in cardiac physiology that was first described anatomically by Turner. This condition may be related to various electrical or functional abnormalities, but no consensus has ever been reached. The purpose of this study was to determine the time of appearance, prevalence and histologic composition of false tendon, as well as its association with innocent murmur in children and with heart disease.

METHODS

The basic research was performed by anatomic dissection of hearts from adult human cadavers to describe false tendon and its histology. The clinical research consisted of echocardiographic study in a pediatric population to identify any relationship with heart disease, innocent murmur in children, or other abnormalities. Fetal echocardiography was performed prenatally at different gestational ages.

RESULTS

False tendon was a normal finding in cardiac dissection and was composed of muscle and connective tissue fibers. In the pediatric population, false tendon was present in 83% on echocardiography and showed a statistically significant association only with innocent murmur in children and slower aortic acceleration. The presence of false tendon was first observed on fetal echocardiography from week 20 of pregnancy.

CONCLUSIONS

Left ventricular false tendon is a normal finding visualized by fetal echocardiography from week 20 and is present until adulthood with no pathologic effects except for innocent murmur during childhood. It remains to be determined if false tendon is the cause of the murmurs or if its absence or structural anomalies are related to disease.

Left ventricular false tendons: echocardiographic, morphologic, and histopathologic studies and review of the literature

BACKGROUND

Left ventricular false tendons (LVFTs) are fibrous or fibromuscular bands stretching across the left ventricle (LV) from the ventricular septum to the papillary muscle or LV free wall but not connecting, like the chordae tendinae, to the mitral leaflet. LVFTs have become the focus of studies and discussions since the advent of echocardiography.

MATERIALS AND METHODS

We prospectively studied the prevalence of LVFTs by two-dimensional echocardiography in 476 infants and children referred to our institute for cardiac evaluation and cardiology workup. We also studied the morphology and histopathology of LVFTs in 68 congenital heart disease specimens and in 20 piglet hearts. The literature was reviewed and the clinical significance of LVFTs was discussed.

RESULTS

LVFTs of varying size and different location were detected in 371 (77.9%) of 476 infants and children studied, in 42 (61.8%) of 68 congenital heart disease specimens, and in 19 (95.0%) of 20 piglet hearts. Of the 75 LVFTs from the congenital heart disease specimens, 33 (44.4%) were fibrous type, measuring less than 1.4mm; 38 (50.7%) were fibromuscular type, 1.5-2.4mm; and 4 (5.3%) were muscular type, 2.5mm or more in diameter. Of the 33 LVFTs from the piglet hearts, 23 (69.7%) and 10 (30.3%) were fibrous and fibromuscular, respectively, and none (0.0%) was muscular.

CONCLUSIONS

LVFTs were detected partially or completely by modified two-dimensional echocardiography in both normal and abnormal hearts. LVFTs is a useful anatomical landmark of LV for the differentiation of morphological LV and right ventricle in segmental analysis of congenital heart disease. LVFTs are a cause of functional murmur. No pressure gradient was noted in the mid-LV or outflow tract. LVFTs could be a contributory factor in the generation of dysrhythmias during LV catheterization studies. LVFTs were more easily identifiable in neonates and young age patients because of a better delineation of images in echocardiography.

Left ventricular apical diseases

There are many disorders that may involve the left ventricular (LV) apex; however, they are sometimes difficult to differentiate. In this setting cardiac imaging methods can provide the clue to obtaining the diagnosis. The purpose of this review is to illustrate the spectrum of diseases that most frequently affect the apex of the LV including Tako-Tsubo cardiomyopathy, LV aneurysms and pseudoaneurysms, apical diverticula, apical ventricular remodelling, apical hypertrophic cardiomyopathy, LV non-compaction, arrhythmogenic right ventricular dysplasia with LV involvement and LV false tendons, with an emphasis on the diagnostic criteria and imaging features.

Epidemiology of left ventricular false tendons: clinical correlates in the Framingham Heart Study

OBJECTIVE

The study objective was to describe the echocardiographic characteristics and investigate the clinical correlates and prognostic significance of left ventricular false tendons (LVFTs). Although LVFTs are generally considered as anatomic variants, they have been associated with innocent precordial murmurs and electrocardiographic abnormalities in small case series. The correlates of LVFTs in the community are unknown.

METHODS

We compared 101 Framingham Study participants with LVFTs (mean age 56 years, 45% were women) on routine two-dimensional echocardiograms with 151 referents without LVFTs (mean age 57 years, 44% were women). We examined the cross-sectional clinical, electrocardiographic (rest and ambulatory), and echocardiographic correlates of LVFTs using logistic regression models and evaluated the prospective association between LVFTs and all-cause mortality using Cox proportional hazards regression models.

RESULTS

A total of 107 LVFTs (94 simple with 2 points of attachment and 13 complex/branching type with 3 or more points of attachment) were identified in 101 participants. LVFTs were most commonly visualized in the apical 4-chamber view (81%) and predominantly localized to the apical third of the left ventricular cavity (78%). LVFTs were associated with the presence of innocent precordial murmurs (multivariable adjusted odds ratio [OR] 5.55, 95% confidence interval [CI], 1.40-21.94) and electrocardiographic left ventricular hypertrophy (OR 4.43; 95% CI, 1.08-18.25). Body mass index was inversely related to the presence of LVFTs (per kilogram/meters squared increment; OR 0.94; 95% CI, 0.88-0.99). LVFTs were not associated with QRS axis deviation, ventricular premature beats, or repolarization abnormalities (all P values > .20). During a mean (+/- standard deviation) follow-up of 7.7 (+/-1.6) years, 15 participants with LVFTs and 19 participants without LVFTs died. In multivariable analyses, the presence of LVFTs was not associated with the risk of death (P = .92).

CONCLUSION

In our community-based sample of middle-aged to elderly white women and men, LVFTs were more likely to be identified in individuals with lower body mass index and cross-sectionally associated with the presence of innocent precordial murmurs and electrocardiographic left ventricular hypertrophy, but they were not associated with the risk of mortality.

False tendons: an endoscopic cadaveric approach

False tendons (FTs) have been extensively described and recognized by gross anatomic studies. However, in the clinical setting the recognition of FTs is limited to the use of echocardiography. We examined 200 formalin fixed adult hearts, with gross dissections. In addition, 90 of these specimens were also examined with ultrasonographic and endoscopic techniques. Gross examination was able to identify FTs in 128 (62%) specimens. The total number of FTs observed, was 248 and was classified into five types according to their location. In Type I (92, 37.1%) the FT was located between the posteromedial papillary muscle and the ventricular septum. In Type II (55, 22.1%) the FT was located between the two papillary muscles. Type III (41, 16.5%) was classified as an FT between the anterolateral papillary muscle and the ventricular septum. The FT in Type IV (31, 12.5%) was observed to connect between the ventricular septum and the free wall and lastly in Type V (29, 11.6%) the FTs were found to be weblike with three or more points of insertion. When using all three techniques (n = 90), gross dissection and endoscopy were able to identify FTs in 62.2% of specimens while echocardiographic imaging was only able to identify FTs in 27.7% of specimens. Of the 114 FTs detected grossly and endoscopically, echocardiography was only able to identify 46 (40.3%). Therefore, the overall sensitivity of echocardiography for detecting left ventricular FTs was only 40.3%, compared to 100% for endoscopy. Based upon the ability or lack thereof of echocardiography to detect certain topographical patterns, we have created a small series of subtypes for the FTs. Histologically, in 30% of the FTs, conduction tissue fiber was observed to be present, which may implicate them in the appearance of arrhythmias.

Echocardiographic and morphologic examination of left ventricular false tendons in human and animal hearts

False tendons are thin, fibrous or fibromuscular structures that traverse the cavity of the left ventricle with no connection to the valvular cusps; they may be single or multiple. We retrospectively analyzed echocardiograms for the prevalence of false tendons in the hearts of 368 (231 male, 137 female) newborns, infants, and children (mean age = 6.28 +/- 4.32 years) who were referred for echocardiography because of suspected acquired or congenital heart disease, but in whom no cardiac pathology was found. In addition, we studied the prevalence of false tendons in 90 hearts from three species of animals (dog, sheep, goat) and eight cadaveric human hearts. In our echocardiographic study, false tendons were detected in 97 of 368 hearts (26.4%). In our gross morphologic studies, false tendons were observed in most of the animal and human hearts: they were present in 5 of 8 (62.5%) human hearts, 14 of 20 (70%) dog hearts, 41 of 50 (82%) sheep hearts, and 16 of 20 (80%) goat hearts. The overall prevalence in animal hearts was 71 of 90 (78.8%). Histologic examination showed the false tendons to be composed of cardiac muscle, blood vessels, fibrous tissue, and Purkinje cells. The possible role of false tendons in innocent murmurs, cardiac rhythm disorders, or left ventricular dysfunction is discussed.

Pitfalls in the echocardiographic diagnosis of intracardiac and extracardiac masses

Transthoracic and transesophageal two-dimensional (2-D) echocardiography remain the procedures of choice for evaluating cardiac mass lesions. Potential errors in diagnosis can be made, however, if the mass lesion's size, shape, mobility, and attachment to other cardiac structures are not clearly delineated. Usually a left atrial myxoma arises from the interatrial septum at the level of the fossa ovalis. Pitfalls in diagnosis occur when the tumor size is very small, or its attachment site is atypical or ill-defined. Atrial thrombi classically reside in an atrial appendage, but can also form in the body of the left atrium. The presence of atrial fibrillation rhythm, enlarged atrial chamber, prosthetic mitral/tricuspid valves, stenotic mitral/tricuspid valves, low cardiac output state, and spontaneous atrial contrast echoes are all features that favor the mass in question being a thrombus. Ventricular thrombi usually occur with poorly functioning ventricles. The diagnosis of ventricular thrombus should be made with great caution if the systolic function is normal, or if the mass has a band or thread-like appearance. A thorough knowledge of normal anatomical variants that can mimic pathological lesions is also important for reaching a correct diagnosis. Last but not least, as in all testing modalities, the patient's clinical picture should be correlated with the echocardiographic findings.

Stunning: damaging or protective to the myocardium?

There are several potential outcomes of myocardial ischemia. When ischemia is severe and prolonged, irreversible damage occurs and there is no recovery of contractile function. Interventions aimed at reducing mechanical activity and oxygen demand, either before ischemia or during reperfusion, have been shown to delay the onset of ischemic damage and to improve recovery on reperfusion. When myocardial ischemia is less severe but still prolonged, myocytes may remain viable but exhibit depressed contractile function. Under these conditions, reperfusion restores complete contractile performance. This type of ischemia, leading to a reversible, chronic left ventricular dysfunction, has been termed hibernating myocardium. Depression of mechanical activity is, actually, a protective mechanism whereby the hibernating cells reduce their oxygen demands in the setting of reduced oxygen supply. A third possible outcome after a short period of myocardial ischemia is a transient postischemic ventricular dysfunction, a situation termed stunned myocardium. As in the case of hibernating myocardium, the depressed contractile function occurring during stunning could be a protective mechanism, allowing the reperfused cells to gradually recover their metabolism and function.

The possible etiology of the vibratory systolic murmur

Between January and September 1985, 476 patients underwent two-dimensional and M-mode echocardiography. Left ventricular bands were noted in 104 of these individuals. Of these patients, 89 (85.6%) were referred for evaluation of a systolic murmur. In view of this high incidence of association between left ventricular bands and systolic murmurs, we decided to perform a prospective analysis on patients with the classical vibratory systolic murmur (Still's murmur) which is commonly found in children and young adults. The incidence of left ventricular bands would be compared with a group of individuals in whom no cardiac murmurs could be detected. It was hoped in this way to possibly determine whether there was a definite relationship between the vibratory systolic murmur and left ventricular bands. Echocardiographs were performed using an Advanced Technical Laboratories machine and gain settings were adjusted such that all artefacts and normal structures could easily be distinguished from the ventricular bands. The ventricular bands were divided into two types. Of significance, we felt, were those which crossed the left ventricular outflow tract and which could therefore have been responsible for the production of turbulence and thus a murmur reminiscent of the Still's murmur. This type of left ventricular band was noted in 76% of our patients with Still's murmurs as opposed to only 14% of the individuals without any murmur (p less than 0.001). This statistically significant difference led us to conclude that left ventricular bands might be the cause of the Still's murmur. Further investigation, particularly with Doppler studies would be required to confirm this interesting association.