A synthesised compound which is also found in bear bile could help prevent disturbances in the heart’s normal rhythm, according to research published today in the journal Hepatology by a team from Imperial College London.
Ursodeoxycholic acid (UDCA) is manufactured as a drug to decrease production of cholesterol in the body and to dissolve gallstones. It is also present in many traditional Chinese medicines made from bear bile.
The new study suggests it could also potentially treat abnormal heart rhythm or arrhythmia, both in the fetus and in people who have suffered a heart attack. Laboratory tests suggested that UDCA acts on non-beating pathological heart cells called myofibroblasts, which interfere with how electrical signals travel across the heart.
UDCA is already used to treat a condition called obstetric cholestasis, which affects around one in 200 pregnant women in the UK and is linked to a higher risk of arrhythmia and sudden death in the fetus. UDCA lowers the levels of harmful bile acids which build up in the mother’s blood in the disease and can pass into the infant through the placenta.
The study published today demonstrates for the first time that UDCA can prevent arrhythmia by altering the electrical properties of myofibroblasts. These cells are found in the fetal heart but disappear shortly after birth. However, they reappear in patients that have had a heart attack, when they are involved in laying down scar tissue.
The study found that these cells disrupt the transmission of electrical signals that control the heart’s rhythm. The study is the result of a long-term collaboration between two Imperial research groups, headed by Juila Gorelik , at the National Heart and Lung Institute and Professor Catherine Williamson at the Institute of Reproductive and Developmental Biology.
"These findings are exciting because the treatments we have now are largely ineffective at preventing arrhythmia in patients who develop an abnormal heart rhythm after a heart attack," said Julia Gorelik, the study’s senior author. "Our results from the lab suggest that UDCA could help the heart muscle conduct electrical signals more normally. We’re hoping to set up a clinical trial to test whether these results translate to patients with heart failure."