Pacemakers and Defibrillators

A heart pacemaker is a small, battery-operated device that sends a signal to your heart. The signal makes your heart beat at the correct pace. Pacemakers may be used:

• For people who have heart problems that cause their heart to beat too slowly, too fast, or in an irregular manner
• For people with heart failure, to match up the beating of both sides of the heart. These are called biventricular pacemakers.

When your heart is weakened, gets too large, and does not pump blood very well, you are at high risk for life-threatening heartbeats.

• An implantable cardioverter-defibrillator (ICD) is a device that detects any life-threatening heartbeats. It then quickly sends an electrical shock to the heart to change the rhythm back to normal.
• Most of today's biventricular pacemakers can also work as implantable cardio-defibrillators (ICD).

Surgery to Improve Blood Supply to the Heart

The most common cause of heart failure when the heart does not beat strongly enough is coronary artery disease (CAD), a narrowing of the small blood vessels that supply blood and oxygen to the heart. CAD may become worse and make it harder to manage your symptoms.

After performing certain tests, your doctor may feel that opening a narrowed or blocked blood vessel will improve your heart failure symptoms. Suggested procedures may include:

• Angioplasty and stent placement
• Heart bypass surgery

Heart Valve Surgery

Blood that flows between different chambers of your heart or out of your heart into the aorta must pass through a heart valve. These valves open up enough so that blood can flow through. They then close, keeping blood from flowing backward.

When these valves do not work well, blood does not flow correctly through the heart to the body. This problem may cause heart failure or make heart failure worse.

As a result, the patient may need surgery to repair one of the heart valves.

Surgery for End-stage Heart Failure

Severe heart failure may need the following treatments when other therapies no longer work. They are often used when a person is waiting for a heart transplant.

You may need a left ventricular assist device (LVAD) if you have severe heart failure that cannot be controlled with medicine or a special pacemaker.

• Ventricular assist devices (VAD) help your heart pump blood from the main pumping chamber of your heart to the rest of your body. These pumps may be implanted in your body or connected to a pump outside your body.
• You may be on a waiting list for a heart transplant. Some patients who get a VAD are very ill and may already be on a heart-lung bypass machine.

Intra-aortic balloon pumps (IABP) help maintain heart function in patients who are waiting for transplants. They can also help those who develop a sudden and severe decline in heart function. The IABP is an implanted thin balloon that is usually inserted temporarily into the artery in the leg and threaded up to the aorta leading from the heart.

References

Mann DL. Management of heart failure patients with reduced ejection fraction. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 28.

Otto CM, Bonow RO. Valvular heart disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 66.

Update Date: 7/29/2011

Updated by: Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.