The most frequent cause of syncope is vasovagal reflex. It is associated with worse quality of life, depression, fatigue and physical injury. Recurrence of vasovagal syncope is an aggravating, reaching the rate of 69%. Initial step and pharmacological treatment may not work, especially in patients with recurrent syncope without prodrome. These patients can present cardioinhibitory response with asystole. Studies were designed to analyses the effectiveness of pacemaker for prevention of syncope. In this review, nonrandomized clinical trials, open-label randomized, double-blind randomized, placebo-controlled, and studies based on tilt test or Implantable Loop Recorder findings will be discussed.

No abstract

No abstract

No abstract

The chemical composition of a feed/diet is the main determinant of its ability to supply nutrients to meet the demands for animal maintenance and production, especially regarding energy supply, which is obtained through digesting and metabolizing the organic components of feeds. Feed composition tables are reliable because they provide exact mean values for energy concentrations. However, there are variations in field conditions that cannot be properly contemplated by data tabulation. Thus, the use of chemical composition to predict the ability of a feed to supply energy can facilitate the work of nutritionists when formulating diets in specific situations, so they can be more exact and appropriate for each productive situation.