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

The investigation of perivasculary space under the myocardial bridge in different species

Our purpose in this study was to investigate the perivasculary space under the myocardial bridges (MB) in dog, sheep, goat and human hearts. A total of 160 hearts were studied, and perivasculary space under the myocardial bridges was examined under microscope. The specimens belonged to 25 dogs, 100 sheep, 25 goats and 10 humans. Special attention was paid to evaluate the distance between the MB and coronary arteries (CA), CA and underlying myocardium (UM) and to find the relation of concomitant vein number accompanying the CA and MB. 219 myocardial bridges were found in total of hearts, and specimens from these bridges were examined under microscope. There were large variations in distance between the MB and CA (0-714 mum) and distance between CA and UM (0-309 mum). The myocardial bridges were classified into three groups in terms of the number of veins accompanying CA, the bridges with no concomitant veins with one concomitant vein and with two concomitant veins. This suggests that the distance between the MB and CA is crucial to determine how much force is on the CA. The environment surrounding the CA may be a crucial factor in determining whether the MB influences the induction of heart disorders or not

The effect of melathonin on changes in brown and white adipose tissue ratios induced by exercise. The significance of age in this effect

[Abstract Not Available

Anthropometric study of patients treated for clubfoot

The anthropometric characteristics of patients treated for clubfoot were used to investigate whether the dimensions of the foot were affected by the method of treatment. A total of 68 patients followed up for an average of 9 years were divided into three groups: group 1, conservatively treated; group 2, surgically treated; group 3, conservatively treated on one side and surgically treated on the other. The following average discrepancies in foot length were obtained: group 1, 0.91 cm; group 2, 1.5 cm; group 3, 1.09 cm. Toe lengths were shorter to the same extent as the other dimensions of the foot. These discrepancies were statistically significant. The following average discrepancies in foot width were obtained: group 1, 0.05 cm; group 2, 0.37 cm; group 3, 0.054 cm; these were insignificant. The authors believe that the degree of discrepancy may depend not solely on the method, but on the severity of the deformity as well

Post-Natal Growth in the Rat Pineal Gland: A Stereological Study

The purpose was to observe the changes in a rat pineal gland using stereological techniques during lactation and post-weaning periods. Thirty Wistar albino rats were studied during different post-natal periods using light microscopy. Pineal gland volume was estimated using the Cavalieri Method. Additionally, the total number of pinealocytes was estimated using the optical fractionator technique. Pineal gland volume displayed statistically significant changes between lactation and after weaning periods. A significant increase in pineal gland volume was observed from post-natal day 10 to post-natal day 90. The numerical density of pinealocytes became stabilized during lactation and decreased rapidly after weaning. However, the total number of pinealocytes continuously increased during post-natal life of all rats in the study. However, this increment was not statistically significant when comparing the lactation and after weaning periods. The increase in post-natal pineal gland volume may depend on increment of immunoreactive fibres, capsule thickness or new synaptic bodies