Electrical fault behind heart trouble

HEALTH: Briefing

A previously unknown electrical problem has been discovered in some heart patients, which may be linked with dangerous rhythm disturbances, it was revealed yesterday. The abnormality prevents the heart from recovering to its normal electrical state after each beat.

Scientists at Johns Hopkins Medical Institute in Baltimore, Maryland, looked at 83 patients with a type of potentially fatal heart failure caused when the lower left chamber of the heart becomes stretched and weakened. A computer was used to analyse the time it takes for cells of the lower chambers to recover electrically from being contracted during a beat.

The results, published in the journal Circulation, showed that this time period varied widely from beat-to-beat, even though they appeared to have stable heart rates. In healthy volunteers, the beat-to-beat interval was relatively stable.

Dr Ronald Berger, who headed the research, said: "This is an important finding that requires further study clinically, to see if this is a predictor for dangerous rhythm disturbances, and mechanistically, to examine on a cellular level why this happens."