A letter from Dr. Bruce Wilkoff, Director of Cardiac Pacing and Tachyarrhythmia Devices, Cleveland Clinic
Heart News
July 14, 2005
Dear current or potential pacemaker or implantable defibrillator patient or family member,
Dr. Bruce Wilkoff
My name is Dr. Bruce Wilkoff, and I oversee the implantable defibrillator and pacemaker operations at the Cleveland Clinic in the Tomsich Family Department of Cardiovascular Medicine. I am speaking on behalf of the physicians and nurses of the Cleveland Clinic implantable device clinic. This device clinic follows over 30,000 patients with implanted pacemakers, implantable defibrillators and biventricular pacing devices. All of these implantable devices are complex and manufactured to very high reliability standards. They treat extremely common and potentially life threatening heart problems related to the electrical system of your heart.
You may have heard either on the radio, television or in the newspapers about the potential for a serious problem that has been identified in some of these devices. I am posting this letter on our Miller Family Heart & Vascular Institute Website to help you put into perspective some of the information that the news media has reported. I will speak most directly to information about these recent media reports about implantable defibrillators which treat and are used to prevent sudden cardiac death from a cardiac arrest. To avoid confusion about the differences between the devices (implanted pacemakers, implantable defibrillators, and biventricular pacing devices) I will briefly describe each type of device.
COMMON TO ALL THREE DEVICES: All are enclosed in a relatively “small”, hermetically sealed metal can, are powered by a lithium based battery that lasts on average from 2-8 years, and have an antennae that allows the nurses and doctors to read information from the device and its activity and to send information to the device to set it up or customize it to each patient’s specific needs. All three devices use leads (wires that carry information back and forth from the heart to the metal device).
PACEMAKER: This device tends to be smaller and prevents the heart rate from going too slowly. It can have one or two leads (wires that go from the metal device to the heart). These leads act as extension cords going through the vein sending messages back and forth between the heart and the pacemaker. The electrical signals from a pacemaker are small and almost always are not felt by the patient. Patients who need a pacemaker commonly have the periodic sensation of lightheadedness or sometimes faint (lose consciousness) in the absence of a pacemaker. The need for pacing usually comes and goes, thus the pacemaker works on demand.
DEFIBRILLATOR (ALSO CALLED AN ICD): This device is a bit larger and includes the activity of the pacemaker but also watches the heart for sudden fast heart rhythms. These rhythms, often called ventricular tachycardia or ventricular fibrillation often cause sudden cardiac death and are responsible for more deaths (over 325,000 per year) in the United States than any other medical cause. When the ICD detects one of these dangerous heart rhythms it responds by either pacing (small impulses not felt by the patient) or shocking (large impulses usually felt by the patient). ICD therapy saves lives. There have been many (over ½ dozen) international studies that have proven the value of defibrillator therapy when compared to drug therapy. These devices also have one or two leads (wires that go from the metal device to the heart).
BIVENTRICULAR PACING OR CARDIAC RESYNCHRONIZATION DEVICES: These devices treat heart failure, a condition when the heart does not pump enough blood to the body. These devices are either a pacemaker or a defibrillator but also have an extra lead (wire that goes from the metal device to the heart). The extra lead activates another part of the heart (left ventricle) which improves the efficiency of the heart to squeeze out more blood with every heart beat.
Although under some circumstances all three types of devices can protect a patient’s life, defibrillators most specifically are used for this purpose. Therefore defibrillators are placed to protect patients from sudden cardiac death. Sudden cardiac death happens frequently in patients with heart disease. Although there are no guarantees with defibrillator therapy, it has been shown to be a very good, very effective and very reliable form of treatment. This is also true of pacemakers and biventricular pacing devices.
Nevertheless, occasionally a defibrillator, pacemaker or biventricular model will be identified as being potentially affected by a problem that could cause the device to fail and not protect the patient. Often the Food and Drug Administration (FDA) will call the situation a recall. However, each situation is different, and while sometimes the device will need to be removed and replaced, in the vast majority of situations THIS IS NOT THE BEST ANSWER.
Often, like the recent situations, the problem is so rare or so mild, that it is very unlikely to be harmful to most patients. In fact, all manufactured devices have a small failure rate. These device problems occur at a rate that is considered within the expected range. In addition, replacement of the defibrillator requires a small surgery similar to the original defibrillator surgery. This surgery, although also associated with very few problems, still has risk just like every surgery. It may be that the surgical risk is larger than the defibrillator’s risk of failure. For these reasons, surgery may not be routinely recommended. For many patients, follow-up visits for defibrillator checks and re-programming options, may be a preferred course. If someone has an affected implantable device they should talk to their doctor about the risks, benefits and alternatives of surgery to replace the device, or follow-up visits.
The most important issue is that you have confidence in implantable defibrillator therapy which protects many people from the most common cause of death in North America. The physicians and nurses at Cleveland Clinic continue to have confidence in the manufacturers of the devices that we implant and the devices themselves.
If you are a Cleveland Clinic Patient: The physicians and nurses of the device clinic at Cleveland Clinic are committed to patient safety, and monitor each situation carefully. We notify Cleveland Clinic patients when we are aware that they have a device with a potential problem. If we follow your defibrillator, pacemaker or biventricular pacing device at Cleveland Clinic, we would be glad to talk to you about this situation at your next visit.
What if you have an implantable device and you are NOT a patient of the Cleveland Clinic? Then you should discuss any questions that you have with your local doctor. Otherwise this information is intended to help you to put information that you see in the newspaper or television or hear on the radio into perspective. Other resources for information about implantable devices are the Miller Family Heart & Vascular Institute Web Pages and the national Heart Rhythm Society.
The physicians and nurses of Cleveland Clinic look forward to caring for you and your implantable device.
Sincerely,
Bruce L. Wilkoff MD
Director of Cardiac Pacing and Tachyarrhythmia Devices
Cleveland Clinic
Click here to learn more about the Heart Rhythm Society and ICD Recalls
