The Use of Combination Pacemakers and Defibrillators
Treatment Modes for Heart Failure
Every year around 550,000 new cases of heart failure are diagnosed, and about 10% of these result in death. Heart failure is a condition where the heart is unable to pump and deliver enough blood to supply the vital organs of the body. This happens when other diseases like atherosclerosis, hypertension, irregular heart rate, and faulty heart valves affect the normal function of the heart to a degree that its muscles fail to contract effectively, leading to a severe, and often fatal, heart attack.
Heart failure is initially treated with medications that are directed to the cause of heart disease and to relieve symptoms such as chest pain and shortness of breath. When these do not suffice, surgery may be needed to correct the underlying defect such as repairing faulty heart valves or creating a bypass in the coronary arteries. Still other forms of treatment are available, such as pacemakers and implantable cardioverter defibrillators.
Combination Pacemakers and Defibrillators
About half of the cases of the heart’s failure to pump effectively are due to a loss of synchronization of the contraction in the ventricles or lower chambers of the heart. This is an electrical function which can be corrected with a pacemaker, a device that can be implanted permanently in the walls of the heart to re-synchronize contractions and produce more efficient delivery of blood to the body.
Implantable cardioverter defibrillators (ICDs) are devices that monitor the heart rate and rhythm through wires that pass through the veins and into the heart. It can sense when the heart goes to a dangerous rhythm (called fibrillations) or stops, and then sends a shock to defibrillate it and convert to normal rate and rhythm.
Pacemakers and ICDs have been used for more than two decades now. In the past surgical implantation of these devices was done separately. However, it was found that there is a possibility of the two devices inappropriately interacting with each other’s function. Two separate implantation procedures could also result in more risks and complications.
The FDA recently approved the use of combination pacemaker-defibrillators which provide dual pacing. This is useful in patients with heart failure and experience abnormal rhythms. Unlike the older units these devices monitor and pace the ventricle as well as the atrium (the upper chamber) of the heart.
Although the cost of the combination device is expensive (around $1,500 more than the cost of a pacemaker), there are more benefits:
- With one device doing two essential functions, it was also found in a recent study that using pacemaker-defibrillators is better than medications or pacemaker alone in decreasing hospitalizations and deaths due to heart failure
- The cost and risks of doing a single procedure is less than doing two separate implantations
- There is a shorter recovery and hospital stay in doing one procedure
- Monitoring and follow-up care are simplified in using one device
Risks in Using Combination Pacemakers and Defibrillators
The use of combination pacemakers and defibrillators has been found to be effective in decreasing the rate of hospitalization and death due to heart failure.
These electrical devices are not free from risks due to malfunction, failure to generate impulses, failure to deliver an electrical shock, erosion from implantation and dislodgement. A patient must therefore be warned to seek medical advice when symptoms of heart failure occur or persist.
It is also important to remember that even with a properly functioning device, not all cases of sudden death are preventable. Cardiac arrest may occur even with a functioning device, especially if the heart is already severely damaged by disease.
References
VUMC, “New Device Combines Pacemaker, Defibrillator” accessed 1/10/11
https://www.mc.vanderbilt.edu/reporter/index.html?ID=294
Medscape, “Pacemakers and Implantable Cardioverter Defibrillators” accessed 1/10/11
https://emedicine.medscape.com/article/780825-overview
UMMC,“STUDY SAYS PACEMAKER/DEFIBRILLATOR DEVICES SIGNIFICANTLY REDUCE DEATH & HOSPITALIZATION IN HEART FAILURE PATIENTS” accessed 1/10/11
