Reducing heart failure in infants

Nearly one of every 100 children is born with a heart defect. More than a third will require surgery and about 25 percent of them will suffer from a condition called low-cardiac output syndrome, or LCOS. This reduction in heart function reduces blood flow to other organs, primarily affecting liver and kidney function and increasing the likelihood of death.

Nearly one of every 100 children is born with a heart defect. More than a third will require surgery and about 25 percent of them will suffer from a condition called low-cardiac output syndrome, or LCOS. This reduction in heart function reduces blood flow to other organs, primarily affecting liver and kidney function and increasing the likelihood of death. A drug called milrinone is being used to treat LCOS. Milrinone improves the heart’s ability to squeeze and can help infants survive LCOS.Doctors at Brenner Children’s Hospital, which is affiliated with Wake Forest University Baptist Medical Center and Wake Forest University School of Medicine in Winston-Salem, took part in the first study of its kind that used milrinone before the onset of LCOS. “It prevented the onset of low-cardiac output syndrome rather than treat it when it occurs”, Dr. Michael Hines, associate professor of cardiothoracic surgery and director of the General Heart Program at Brenner Children’s Hospital, said. Usually, doctors wait until symptoms of LCOS appear before administering milrinone. The drug has few side effects, but can cause a temporary drop in blood pressure.About 240 patients from nearly 30 hospitals across the country recently participated in a study of milrinone. One group of children received a low dose of milrinone; another group a high dose, and a third group received a placebo. The infants who were given milrinone received it immediately after heart surgery. During the first 36 hours after surgery, the infants who received the high dose of milrinone were 55 percent less likely to suffer from LCOS than those who received the placebo. Since the drug reduced the onset of LCOS, it also reduced the complications caused by LCOS. “Those are the things that keep kids in the hospital extra days or in the intensive care extra days,” Hines said.Infants seem to absorb milrinone much better than adults, who may sometimes experience low blood pressure, blood platelet abnormalities and irregular heart rhythms after taking the drug. Researchers from the Department of Anesthesiology at the University of Washington School of Medicine studied milrinone in infants and children after open-heart surgery. They concluded that the major complications from the milrinone were thrombocytopenia. Thrombocytopenia is a disorder in which the number of platelets — a type of blood cell — is abnormally low, sometimes associated with abnormal bleeding. Thrombocytopenia can also be associated with cancers of the blood and with disorders that cause bone marrow dysfunction. However, researchers agree that milrinone results appear to be promising for infant patients. Further research will be needed to evaluate long-term effects and determine the optimal dosage, researchers conclude.(Source: Austin News: June 2004)