U.S. Vice President Dick Cheney left a hospital in Washington Saturday following a scheduled operation to replace a battery in a device that monitors his heart.
Mr. Cheney has a history of heart trouble. He has suffered four heart attacks, the most recent in 2000.
An internal defibrillator was implanted in his chest in 2001. The device monitors his heartbeat and administers an electric shock to the heart muscle to correct irregular beats.
During Cheney's routine physical examination last month, his doctors noticed the defibrillator's battery had weakened to the point that it should be replaced.
Cheney's office said the device had been operating normally and had not had to correct any irregular heartbeats.
INTERNAL DEFIBRILLATOR
An internal defibrillator is a small, battery powered electrical impulse generator that is implanted in patients who are at risk for sudden cardiac arrest. They provide an electrical shock to the heart during periods of irregular heartbeat, and can save someone’s life. Internal defibrillators sense intrinsic cardiac electric potentials, and then send electrical impulses if the potentials are either too infrequent of absent, due to a problem with the patient’s heart. The electrical pulses stimulate the myocardial contraction, which causes the heart to beat at a normal rhythm.
The process of implanting an internal defibrillator is similar to the implantation of a pacemaker, since both devices contain electrode wires that are passed through a vein to the right chambers of the heart. In most cases, the wires are lodged in the apex of the right ventricle, and the device is kept in the patient as long as they live.
An internal defibrillator works to continuously monitor the heart, and detects overly rapid arrhythmias. They can detect ventricular tachycardia, which are a rapid regular beating of the ventricles and the bottom chambers of the heart. Internal defibrillators can also detect a rapid irregular beating of the ventricle, which is referred to as ventricular fibrillation.
When a patient experiences either of these arrhythmias, the pumping efficiency of the heart is impaired. Fainting and sudden cardiac arrest are usually a result if a patient experiences an arrhythmia, but an internal defibrillator can prevent that from occurring. Patients with coronary heart disease and heart muscle diseases tend to experience arrhythmias; therefore they are the most qualified candidates for an internal defibrillator.
The implantation of an internal defibrillator is much less invasive than is used to be, due to advanced techniques and technology. An internal defibrillator is a tiny computer hooked up to a battery, and then placed inside a tiny titanium case. It weighs only about three ounces, and is about the size of a cassette tape. The device is implanted under the skin below the collarbone, and tiny wires are used to send signals from the heart to the internal device. A programmer is also found on the small device, and it allows a doctor to set it at the correct rhythm for each specific patient.
The internal defibrillator is able to correct irregular and regular heart rhythms, just by sending a timed and calibrated electrical shock directly to the heart. It is similar to a defibrillator used in hospitals when someone’s heart stops, yet it is implanted in the body and ready to be used at any time. It can save the life of a loved one suffering from a heart problem, because a stopped heart needs to be shocked right away. By preventing cardiac arrest, patients with heart problems can live normal lives without having to worry. Patients with internal defibrillators can live normal lives and participate in activities they like, since they don’t have to worry about experiencing cardiac arrest or any other serious heart problems.
No comments:
Post a Comment