A device to fix the heart’s rhythm

An irregular heart beat or arrhythmia occurs when one side of the lower heart is electrically stimulated a fraction of a second later than the other side. Doctors don’t know why some people develop this problem, but a device approved in 2001 by the FDA is the single most important heart-failure therapy of the last decade, according to this story in a special report on heart health – Matters of the Heart.

Cardiac resynchronization therapy, or CRT, can fix the problem where medications failed. Resynchronization improved heart-pumping strength, exercise capacity, and quality-of-life indicators. Major studies showed it also reduced hospitalizations by more than a third, and deaths by a quarter.

The mortality benefits are even greater when the resynchronizer is combined with a defibrillator, which shocks the heart back to a normal rhythm if it beats too fast. Many patients are diagnosed with both kinds of arrhythmias through monitoring tests and electrocardiograms.

"There are patients who probably would have needed a heart transplant without CRT," said Howard Eisen, chief of the cardiology division at the Drexel University College of Medicine.