Pacemakers and internal defibrillators are two types of cardiovascular implants. Though both devices use electrical pulses to treat similar conditions, key differences in their functions make each ideal for different circumstances. Here, Richmond University Medical Center explains what sets defibrillators vs. pacemakers apart and when a patient may be a good candidate for each.
What Do Defibrillators and Pacemakers Treat?
Both defibrillators and pacemakers are designed to treat arrhythmias. An arrhythmia is when the heart beats too quickly, too slowly, or with an erratic rhythm. Most arrhythmias are caused by changes in the electrical signals that tell the heart when to beat. A variety of different conditions can influence these signals and cause an arrhythmia. These include:
- Cardiac arrest
- Coronary artery disease
- Cardiomyopathy
- Diabetes
- High blood pressure
- COVID-19
- Over- or under-active thyroid gland
- Sleep apnea
- Certain medications
- Excess alcohol or caffeine
- Drug misuse
- Smoking
- Stress
- Genetic factors
Some arrhythmias are mild enough to be only minor concerns. Severe ones, however, can cause life-threatening complications. Internal defibrillators and pacemakers are tools used to prevent severe arrhythmias by correcting faulty electrical signals. This helps the patient stay healthy and safe from health emergencies.
What Is an Internal Defibrillator?
An internal cardioverter defibrillator, also called an ICD, is a medical device that is surgically implanted inside the patient’s body. It features a generator, which is placed under the sternum or in the abdomen, and sensors, which rest on or inside the heart.
The purpose of an ICD is to monitor the patient’s heart rate. When it detects a change or irregularity in rhythm, the ICD delivers a low-energy electric shock to the heart. This shock either speeds up or slows down the patient’s heart rate to restore a normal rhythm. If the low-energy shock is not effective in correcting the heart rate, or if the heart is beating very quickly or irregularly, the ICD may deliver a second, higher-energy shock.
ICDs can also be used to record the patient’s heart rhythm. During a checkup, this recording helps the physician understand how well the defibrillator and other treatment methods are working. They can then adjust their treatment plan as necessary.
What Do Internal Defibrillators Treat?
The brief, high-energy shock delivered by an ICD makes it the best solution for tachycardia, or a too-fast heartbeat. In most cases, physicians recommend them to patients who are at risk of sudden cardiac arrest, a condition that occurs when the heart stops entirely due to an arrhythmia. These are some common circumstances where an ICD may be recommended:
- The patient has previously experienced sudden cardiac arrest.
- The arrhythmia develops or worsens after a heart attack.
- The arrhythmia is due to a genetic condition or structural defect.
- There are issues with the heart’s signaling pathways.
What Is a Pacemaker?
Like an ICD, a pacemaker is an implanted medical device. Its structure is similar to an ICD’s: there is a generator, typically placed just under the patient’s skin; and one, two, or three sensors, which are placed in the different chambers of the patient’s heart. Wireless pacemakers are also available.
The pacemaker’s sensors monitor the heart rhythm to ensure it remains steady. If it detects an irregularity, it works to correct it. Unlike an ICD, however, pacemakers do not deliver a single high-energy shock. Instead, they work by delivering steady, low-energy shocks to the heart. Each shock prompts a beat, helping the heart return to a normal rate and rhythm over a long period of time. The speed at which shocks are delivered is called the pacing rate.
Similar to an ICD, the pacemaker can also record heart rate data. The physician may use this data to monitor the pacemaker’s effectiveness. If the pacemaker is not working as intended, the physician can reprogram the pacing rate for better results.
What Do Pacemakers Treat?
The consistent electric pulses of pacemakers make them most suitable for treating bradycardia, or a too-slow heartbeat. It may also be used for hearts that frequently pause their beating, or whose chambers occasionally beat out of sync. Vascular conditions treated with a pacemaker include:
- A previous heart attack
- Structural problems in the heart
- Issues with the heart’s signaling pathways
- Specific types of muscular dystrophy
Patients with more serious conditions, such as heart failure or cardiomyopathy, are better candidates for an ICD.
Compare Defibrillators vs. Pacemakers With Richmond University Medical Center
If you or a loved one has a heart condition that causes arrhythmia, seek care at Richmond University Medical Center. Our cardiovascular Department in Staten Island, New York, is staffed by a team of compassionate specialists and cardiologists who can help you determine which device is best for you. Contact us today to learn more about heart treatments and defibrillators vs. pacemakers.
