Falsos Tendões - Vc sabia? - by Fábio Soares

- Correspondem a estruturas finas que se estendem desde o septo interventricular para os músculos papilares, próximo a parede lateral do VE. Em alguns pacientes pode se apresentar como um"Y" ou em forma de rede. Basicamente falso tendão é uma estrutura fibromuscular que é não-patológica.

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

Kenchaiah S, Benjamin EJ, Evans JC, Aragam J, Vasan RS.

J Am Soc Echocardiogr. 2009 Jun;22(6):746-7.

Abstract

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.

- Talvez essas estruturas não sejam simplesmente um achado casual ao ecocardiograma. Você sabia?

1. Falsos tendões podem ter efeito benéfico em pacientes com cardiomiopatia dilatada, limitando o remodelamento negativo e diminuindo a gravidade da insuficiência mitral.
http://jtcs.ctsnetjournals.org/cgi/content/abstract/138/5/1123
2. Sítio de arritmias ventriculares por provável mecanismo de reentrada

Anatomic Substrate for Idiopathic Left Ventricular Tachycardia

Ranjan K. Thakur, MD; George J. Klein, MD; Chittur A. Sivaram, MD; Marco Zardini, MD; David E. Schleinkofer, MD; Hiroshi Nakagawa, MD; Raymond Yee, MD; Warren M. Jackman, MD

Background Idiopathic left ventricular tachycardia (ILVT) characterized by QRS complexes with right bundle-branch block (RBBB) morphology and left axis deviation is a distinct clinical syndrome that also demonstrates a characteristic response to verapamil and inducibility from the atrium in patients without structural heart disease. A false tendon has been described in the left ventricle in a patient with ILVT in whom surgical resection of the false tendon resulted in cure. We hypothesized that the false tendon is responsible for the genesis of similar ventricular tachycardia (VT) in others.

Methods and Results We performed transthoracic (TTE) and/or transesophageal (TEE) two-dimensional echocardiograms in 15 patients undergoing catheter ablation for ILVT. There were 12 men and 3 women (mean age, 31±12 years, with average symptom duration of 11±9 years). The mean VT cycle length was 360±70 ms, and all had RBBB morphology with left axis deviation. Cardiac chamber sizes, left ventricular wall thickness, and wall motion were normal in all ILVT patients. TTE and/or TEE demonstrated a false tendon extending from the posteroinferior left ventricular free wall to the left ventricular septum in all ILVT patients. The false tendons were thick (2 mm maximal thickness) in 5 patients and thin (<2 mm maximal thickness) in 10 patients. We compared ILVT patients with a control group of 671 consecutive patients referred for echocardiography for other reasons. The mean age for the control group was 42 years. A false tendon was seen in the left ventricle in 34 of 671 (5%). In the control group patients with a false tendon, 2 patients had a history of VT (left bundle-branch block morphology) and 1 had ventricular fibrillation. The false tendons in the control patients were also oriented transversely across the ventricular cavity but were somewhat thinner (<2 mm maximal thickness in 32 of 34 patients). Catheter ablation with the use of radiofrequency and/or direct current applied to the posteroapical septum resulted in cure in 14 of 15 patients.

Conclusions A false tendon extending from the posteroinferior left ventricle to the septum is a consistent finding in patients with ILVT and probably is responsible for this unique arrhythmia. The mechanism by which the false tendon precipitates tachycardia is speculative, but possibilities include conduction through the false tendon or by producing stretch in the Purkinje fiber network on the interventricular septum.