乌鸦传媒

The heart is a finely tuned machine, pumping and squeezing to move blood through the body with a fresh supply of oxygen and nutrients. Electrical activity provides the spark to coordinate and activate heart muscle movement.

In heart failure, the electrical activity that sets a normal heart rhythm can also misfire, resulting in what is called arrhythmia. Implanted devices can correct or prevent faulty electrical signals.

One type of cardiac device often used for individuals with heart failure is an implantable cardioverter-defibrillator (ICD). When this device senses a dangerous arrhythmia that would stop the heart, it can either start sending electrical signals (called antitachycardia pacing) to restore a normal heart rhythm or send a strong jolt of electricity to try to prevent sudden cardiac death.

Another common device is a type of pacemaker that delivers cardiac resynchronization therapy (CRT), also called a biventricular pacemaker. It has electrical wires into both sides of the heart to sync up their timing of electrical activity, which helps the heart work more efficiently.

While ICDs and CRT devices save lives, they do carry some risks. Cardiac devices like these are inserted under the skin, typically just below the collarbone, during a surgical procedure. The "pocket" where the device sits or the wires that go from the device into the heart can become infected. Some 5% of patients, or 1 in 20, experience an within 3 years of getting their device. If this happens, the device or leads or both may have to be replaced.

When the device battery runs low, the device may need to be replaced as well. ICDs last on average, depending on how the device is programmed to run. CRT devices may last . Your doctor will monitor the battery life on your device at regular checkups.

An ICD may also sense danger and deliver a shock unnecessarily, which can be painful. This happens in an estimated of individuals over 2 years.

As your heart failure becomes more advanced or other health conditions arise that change your goals of care, talk with your doctor about your wishes. Some people choose to have their ICD device turned off so as not to deliver unwanted shocks or prolong life when not desired.

Read previous installments in this series:

For Your Patients: What is Heart Failure?

For Your Patients: How Is Heart Failure Diagnosed?

For Your Patients: Getting the Most From Heart Failure Visits

For Your Patients: Self-Care for Heart Failure

For Your Patients: What to Expect From Cardiac Rehabilitation

For Your Patients: Managing Heart Failure With Other Chronic Conditions

"Medical Journeys" is a set of clinical resources reviewed by doctors, meant for physicians and other healthcare professionals as well as the patients they serve. Each episode of this journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.