Tags：Implantable Cardiac Defibrillators (ICDs)——medical tourism
For those who are at high risk of the deadliest forms of arrhythmias – ventricular tachycardia and ventricular fibrillation – an internal “shocking” device may provide the best defense against sudden cardiac arrest. Such a device, known as an implantable cardioverter defibrillator (ICD), is considered effective in fighting cardiac arrest over 90 percent of the time, an astounding success for a condition that few survived as recently as 15 years ago.
Implantable cardioverter defibrillators (ICDs) are small devices, about the size of a pager, that are placed below the collarbone. Via wires, or leads, these devices continuously monitor the heart’s rhythm. If the heart beats too quickly, the ventricles will not have enough time to fill with blood and will not effectively pump blood to the rest of the body. Left unchecked, the rapid heartbeat could cause death. To intervene, the ICD issues a lifesaving jolt of electricity to restore the heart’s normal rhythm and prevent sudden cardiac death.
ICDs also can act as pacemakers when a heart beat that is too slow (bradycardia) is detected.
Most ICDs keep a record of the heart's activity when an abnormal heart rhythm occurs. With this information, the electrophysiologist, nurse practitioner or electrophysiology nurse who is a specialist in arrhythmias, can study the heart's activity and ask about other symptoms that may have occurred. Sometimes the ICD can be programmed to “pace” the heart to restore its natural rhythm and avoid the need for a shock from the ICD. Pacing impulse from the ICD are not felt by the patient; shocks are felt, and have been described as a kick in the chest.
When is ICD Therapy the Right Choice?
In the simplest terms, anyone who has had or is at a high risk of having ventricular tachycardia, fibrillation or sudden cardiac arrest is a candidate for an ICD.
A cardiac arrhythmia specialist (electrophysiologist) should evaluate cardiac patients if they have experienced any of the following:
A prior cardiac arrest
Ventricular tachycardia (VT) which is an episode of rapid heartbeat originating from the lower chambers of the heart.
Ventricular fibrillation (VF), which is similar to VT but is characterized by a heartbeat that is too rapid and is irregular or chaotic.
Ejection fractions of less than 35 percent. An ejection fraction (EF) is the proportion, fraction, or percentage of blood pumped by the heart with each beat. A normal heart pumps out a little more than half the heart's volume of blood with each beat, making a normal EF 55 percent or higher.
Patients at a high risk for sudden cardiac death (SCD) because of an inherited heart abnormality.
How Effective Are ICDs?
Studies of ICDs show they are 99 percent effective in detecting and stopping deadly heart rhythm disorders. In clinical trials, ICDs have been shown to be the most successful therapy to prevent sudden cardiac death in certain groups of high-risk patients.
Common Questions About ICDs
Can I use a cellular phone?
Yes, with these general guidelines:
Hold the phone to the ear on the side of the body opposite of the implanted device.
Do not carry the phone in the ON position in a breast pocket over or within 6 inches of the ICD.
Maintain a minimum of 6 inches between the ICD and the phone.
Are security systems and airports a problem?
Walk normally through theft detector systems. Carry your ID card with you at all times. Show the airport security people the card, and ask to be hand searched.
Can an ICD patient drive a car?
Many physicians recommend no driving for 6 months after implantation of an ICD, or after a shock. Commercial drivers may be restricted from driving. Discuss this issue with your physician to maintain your safety as well as that of others.
How does it feel?
Fast pacing therapy may feel like a flutter or palpitation in the chest, or nothing at all. The shocks may feel like a sudden painful kick in the chest. It occurs in an instant and then is gone. If a blackout occurs, the shock may not be felt. Someone touching the patient may feel a small muscle jerk. It will not harm them.
How and when is the battery replaced?
The battery check at each visit will determine when the ICD should be replaced. The electronic circuitry as well as the battery are sealed inside the ICD. When replacement time arrives the lead(s) will be tested and then a new ICD is attached to the lead(s). Usually the original lead(s) are reused.