Implantable devices have been used for decades to treat heart disease. The first pacemaker was implanted over 40 years ago, and implantable defibrillators were first used in the early 1980s. But the last few years have witnessed a surge in both the types of devices being tested for heart-failure treatment, and in the optimism of experts about their usefulness.
Heart failure is a condition in which the heart can't pump blood effectively to the lungs or the rest of the body.
This can be because the person has developed a weakened heart muscle or because the heart muscle has thickened or stiffened, making it difficult to fill the heart and backing up blood into the lungs.
With heart failure, the weakened heart pumps less blood than usual, causing the kidneys and adrenal glands to produce chemicals that help the body to hold onto salt and water.
"A lot of the big advances that we've had in treating heart failure in the last few years has been with devices," says Marvin A. Konstam, MD, chief of cardiology and director of cardiovascular development at Tufts-New England Medical Center. "It's an exciting time."
Eric Rose, MD, agrees. "Things are dramatically different in the last five years," says Rose, department of surgery chairman at the Columbia University College of Physicians and Surgeons. "For instance, the dream of using machines for long-term supportive patients with end-stage heart failure is now a reality."
But Rose, who led a study of one such implant used in heart-failure treatment -- the left ventricular assist device -- is temperate in his enthusiasm. "It's a reality, but I should say that it's a reality with mediocre outcomes at this point," he tells WebMD. "That's still an improvement over God-awful, which is what the prognosis was before."
While advances in devices are impressive, all experts agree that we are only in the early stages of their development. It remains to be seen how widely and how quickly these life-saving implants will become available for routine heart-failure treatment.
Given that heart failure is not a specific disease in itself, but rather a condition that results from other illnesses, different approaches have been developed to treat the condition. Some stem from the familiar pacemaker, others from devices designed as a stopgap before heart transplant.
Implantable Cardioverter Defibrillators (ICDs)
An ICD is used for heart-failure treatment when the person is considered to be a high risk of dying from an abnormal heart rhythm -- called sudden cardiac death. It is a small device that is implanted in the chest and continually monitors the heart's rhythm. If the ICD senses a dangerous abnormal heart rhythm, it delivers an internal electric shock to the heart -- the equivalent of being shocked with paddles outside the body -- that hopefully restores a normal heart rhythm.