Tricuspid regurgitation (TR), also called tricuspid insufficiency, is a type of valvular heart disease in which the tricuspid valve of the heart, located between the right atrium and right ventricle, does not close completely when the right ventricle contracts (systole). TR allows the blood to flow backwards from the right ventricle to the right atrium, which increases the volume and pressure of the blood both in the right atrium and the right ventricle, which may increase central venous volume and pressure if the backward flow is sufficiently severe. The causes of TR are divided into hereditary and acquired; and also primary and secondary. Primary TR refers to a defect solely in the tricuspid valve, such as infective endocarditis; secondary TR refers to a defect in the valve as a consequence of some other pathology, such as left ventricular failure or pulmonary hypertension.The mechanism of TR is either a dilatation of the base (annulus) of the valve due to right ventricular dilatation, which results in the three leaflets being too far apart to reach one another; or an abnormality of one or more of the three leaflets. Signs and symptoms
The symptoms of TR depend on its severity. Severe TR causes right-sided heart failure, with the development of ascites and peripheral edema.A pansystolic heart murmur may be heard on auscultation of the chest. The murmur is usually of low frequency and best heard on the lower left sternal border. It increases with inspiration, and decreases with expiration: this is known as Carvallos sign.
The process requires phosphates, magnesium and potassium which are already depleted, and the stores rapidly become used up. Formation of phosphorylated carbohydrate compounds in the liver and skeletal muscle depletes intracellular ATP and 2,3-diphosphoglycerate in red blood cells, leading to cellular dysfunction and inadequate oxygen delivery to the bodys organs. Intracellular movement of electrolytes occurs along with a fall in the serum electrolytes, including phosphate and magnesium. Levels of serum glucose may rise, and B1 vitamin thiamine may fall. Abnormal heart rhythms are the most common cause of death from refeeding syndrome, with other significant risks including confusion, coma and convulsions and cardiac failure. Clinical situations
The syndrome can occur at the beginning of treatment for anorexia nervosa when patients have an increase in calorie intake and can be fatal. It can also occur after the onset of a severe illness or major surgery. The shifting of electrolytes and fluid balance increases cardiac workload and heart rate. This can lead to acute heart failure. Oxygen consumption is increased which strains the respiratory system and can make weaning from ventilation more difficult. Diagnosis
Refeeding syndrome can be fatal if not recognized and treated properly. An awareness of the condition and a high index of suspicion are required in order to make the diagnosis. The electrolyte disturbances of the refeeding syndrome can occur within the first few days of refeeding. Close monitoring of blood biochemistry is therefore necessary in the early refeeding period.