Green tea catechin may prevent life-threatening cardiac arrhythmias

Epigallocatechin-3-gallate (EGCG) in green tea could help prevent the dangerous alterations in heart rhythms known as ventricular arrhythmias, that can follow a heart attack, according to a study presented at the Heart Rhythm Society's 25th Annual Scientific Sessions, held in San Francisco in May 2004. Ventricular arrhythmias include ventricular tachycardia and ventricular fibrillation, which are commonly associated with heart attacks or with the scarring of the heart muscle that occurred during the event.

Tea drinkers have been known to have a lower rate of death following a heart attack than those who do not drink tea. A team from the University of Heidelberg, in Heidelberg, Germany, sought to find out why.

By studying frog egg cells, the researchers found that EGCG inhibited HERG potassium channels, which are involved in cardiac repolarization. The HERG potassium channel is present in Long QT syndrome, a cardiac electrical disorder that can be inherited or caused by taking certain medications. Individuals with the disorder are susceptible to ventricular fibrillation. HERG potassium channels are also overexpressed in extracardiac tumors.

Heart Rhythm Society president Michael E. Cain, MD, commented, "This is an interesting development in the battle against these serious and life-threatening disorders. While this is a preventive action that may be beneficial, it is important to continue with your current medications and health regimen."

Key concepts: Green tea, EGCG, cardiac arrhythmias