False tendons in the left ventricle: 2-dimensional and M-mode echocardiographic findings

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.

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.

Incidence and distribution of left ventricular false tendons: an autopsy study of 483 normal human hearts

The incidence and distribution of left ventricular false tendons were studied in a series of 483 autopsy specimens of human hearts from subjects evenly distributed by sex and age. False tendons were observed in 265 specimens (55%), and their incidence was greater in hearts from male than from female subjects (61 versus 49%; p less than 0.01). Neither the incidence nor the location of false tendons varied appreciably with age. Of the 265 specimens containing false tendons, 100 (38%) exhibited 2 or more, such that the total number of false tendons identified was 414. Of these 414, 272 (66%) were located between the posteromedial papillary muscle and the ventricular septum, 49 (12%) between the two papillary muscles, 47 (11%) between the anterolateral papillary muscle and the ventricular septum, 38 (9%) between the free wall and the septum and 3 (less than 1%) between two aspects of the free wall; 5 (1%) had three or more points of insertion and formed weblike structures. False tendons are common anatomic variants of the normal human left ventricle which may be detected by two-dimensional echocardiography and should not be misinterpreted as pathologic structures such as flail mitral chordae tendineae or mural thrombi.

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

Left ventricular bands were prospectively identified in 31 of 218 (14.2%) children undergoing an initial two-dimensional echocardiogram for suspected or known cardiac disease. Left ventricular bands usually coursed from the midportion of the interventricular septum to the free wall of the left ventricle. Most of the bands were detected in the apical four-chamber view. In 7 of 31, an hourglass configuration of the left ventricular cavity was noted. Diagnostic left ventricular angiography was performed in 9 of 31 patients, and in seven of nine the band was delineated. The echocardiographic and angiographic findings in children with left ventricular bands are discussed and the literature is reviewed.

Strings containing left bundle branch conductive tissue in the left ventricle. Observations in man

Several reports have demonstrated the presence of strings within the heart chambers e.g.: on the basis of autopsy materials (Goforth 1926, Knoblich et al. 1962, Hudson 1965, Gould 1968, Roberts 1969, Franck 1970, Olsen & Valentine 1972) or by echocardiography (Nishimura et al. 1981, Choo et al. 1982, Lindvall et al. 1982, Asmussen submitted for publication). Prompted by the echocardiographic observations by Asmussen (Asmussen submitted for publication) we tested the hypothesis that left ventricular strings may contain left bundle branch conductive tissue. During a six months' survey period at the Laboratory of Pediatric Pathology we found two such cases. It is suggested that left bundle branch block and/or hemiblock may be a consequence of this abnormality in the event of stretching or rupture of such strings.

Incidence of the coexistence of left ventricular false tendons and premature ventricular contractions in apparently healthy subjects

The incidence of the coexistence of left ventricular false tendons and premature ventricular contractions (PVCs) was evaluated prospectively. Over 14 months, left ventricular false tendons were found in 71 (6.4%) of 1117 consecutive patients examined echocardiographically. Two types of false tendons were observed: longitudinal, from the ventricular septum to the posteroapical wall (n = 62), and transverse, between the septum and the lateral wall (n = 9). Among 62 patients with PVCs and no underlying heart disease, false tendons were detected in 35 (56%); 28 had unifocal and seven had bifocal PVCs. Episodes of ventricular tachycardia were documented in one of the 28 patients with unifocal PVCs and in one of the seven patients with bifocal PVCs. These PVCs were poorly controlled by antiarrhythmic drugs but easily suppressed by exercise. Left ventricular false tendons were detected in 36 patients on routine echocardiographic examinations performed in the other 1055 subjects, and 10 of these patients were judged to have no underlying heart disease. PVCs were detected in two (20%) of these 10 patients. Although a definite conclusion that left ventricular false tendons are arrhythmogenic cannot be derived from these results, the unexpectedly high incidence of the coexistence suggests that left ventricular false tendons may be an etiologic factor in the development of PVCs, especially the rate-dependent and medically uncontrollable PVCs seen in apparently healthy individuals.

Left ventricular false tendons: echocardiographic incidence in India and clinical importance

In a prospective study of 1012 patients above the age of 12 years, we detected 4 (0.4%) cases of left ventricular false tendon (LVFT) by echocardiography. Two patients had significant heart disease and LVFT was perhaps a chance occurrence; two others had no significant heart disease and LVFT probably had a causal association with S3 gallop in one and systolic murmur in the other. Diagnosis of LVFT may help to explain cardiac findings of uncertain origin.

Left ventricular false tendons in children: prevalence as detected by 2-dimensional echocardiography and clinical significance

During a 28-month period, consecutive 2-dimensional echocardiograms were reviewed to determine the prevalence of left ventricular (LV) false tendons, their associated anomalies and clinical significance. LV false tendons were found in 31 (0.8%) of 3,847 consecutive 2-dimensional echocardiograms. Of 31 LV false tendons, 30 passed longitudinally from papillary muscle to septum and 1 went from free wall to free wall. The 31 patients were aged 1 day to 15 years. Associated heart disease, most often ventricular septal defect, bicuspid aortic valve and coarctation of the aorta, was present in 48%, of whom 73% were girls. Of those without heart disease, 69% were boys. In patients with heart disease, precordial murmurs were due to the underlying cardiac anomaly. Of those without heart disease, 15 of 16 (94%) had a precordial murmur, usually of the Still's type over the lower left sternal border. Four of 31 (13%), 1 with and 3 without heart disease, had unifocal premature ventricular contractions that were rate-dependent in the 2 patients undergoing stress testing. LV false tendons appear to occur in 0.8% of pediatric patients and usually are accompanied by a Still's type innocent murmur if unassociated with heart disease. Some LV false tendons are associated with rate-dependent premature ventricular contractions.