What’s The Difference Between A Defibrillator And A Pacemaker?

History of Cardiac Treatments

In the early 20th century, more resources and health professionals became committed to treating patients with heart disease. Longer lifespans made heart disease much more prevalent in the older population. One of the most important diagnostic tools to help identify heart issues was the ECG or the electrocardiograph.

Physicians in the late 19th century began attempts to record heart rate and rhythm using rudimentary devices. Electrical engineer Alexander Muirhead first used wires to monitor a heart rate in 1872. In 1887, the first ECG machine was invented by British physiologist Augustus Waller. 

He used a capillary electrometer and a projector to record and trace the patient’s heart rate. By the middle of the 20th century, the ECG had evolved into a standard device to measure heart rate and diagnose issues like arrhythmia and coronary artery disease.

Using Electrical Current

Throughout the same time period of the ECG’s development, other teams of physicians and researchers were making discoveries about how electricity impacted the heart. 

Doctors began working on devices that could use electrical currents and pulses to change the heart rate and rhythm. The first designs of these devices were used only during open heart surgery on patients with nearly fatal cardiac arrest events. 

By 1947, the first patient had been successfully resuscitated from a cardiac arrest with an electrical shock delivered to the heart via metal paddles. Eventually, external devices were designed that allowed the heart to be successfully shocked back into a regular rhythm. 

The Role of the Defibrillator 

The electrical shocking device that had been successfully used to bring back patients from cardiac arrest was termed the defibrillator. Defibrillators send small, electrical shocks to the heart in order to get its rhythm back into a regular rate, or restart the rhythm altogether. 

Most devices use two paddles and place them in different spots on the chest or on the actual heart before delivering the electrical pulses. Many defibrillators that are used today are small, portable devices called automated external defibrillators, or AEDs, which are found in many public places and can be easily operated by almost anyone. Other defibrillators are able to be implanted into a patient’s body in order to help correct a life-threatening arrhythmia.

Indications for a Defibrillator 

The use of a defibrillator, such as an AED, is typically utilized for emergency situations only, rather than long-term management of a heart issue. AEDs are generally indicated when someone suffers from a life-threatening heartbeat that is too fast. 

When a victim experiences SCA, an AED is the only medical device that can return the heart rhythm to a normal one. They are very easy to use, providing step by step audio instructions, but they must be administered within minutes of a patient’s collapse. AEDs automatically determine if an electrical shock is needed. In a hospital setting, defibrillators are also administered at times to reverse a sudden cardiac arrest and save a patient.

Implantable Cardioverter-Defibrillators

Implantable devices deliver long-term heart arrhythmia treatment for those at an elevated risk of SCA. . The ICD, or implantable cardioverter-defibrillator, also employs electrical pulses to help treat patients who experience a sudden, dangerous heart rhythm.

These devices are implanted into the body and monitor the heart rate for potential arrhythmia. If an irregular, fast or slow heart rate is detected, the device delivers electrical shocks to the heart rhythm to normal.. Some people are prescribed an ICD after having a heart attack or if there is a  history of cardiac arrest from an arrhythmia.

Pacemaker Information  

An additional, common heart device that some doctors implant into patients is called a pacemaker. Pacemakers may be surgically implanted or simply placed just below the skin to help control the heart rate on a consistent basis. 

Pacemakers use small, electrical impulses to control the heart rhythm. They became a treatment option starting in 1958 when the first pacemaker was placed into a patient. By 1969, with the introduction of the first lithium battery, pacemakers were able to last longer and did not need to be replaced as frequently.

Indications for a Pacemaker 

Pacemakers are prescribed for a variety of cardiac issues. One indication for a pacemaker is if there is a history of the heart beating too fast or too slowly. If drug therapy hasn’t improved the heart’s rhythm, a pacemaker may be recommended. 

Another reason a pacemaker may be indicated is if a patient has had a heart ablation procedure performed. Some patients who have had an ablation may need a pacemaker to control the heart’s electrical impulse. This occurs because of the procedure potentially damaging the AV node on the organ and causing irregular heart rhythms. 

Patients who regularly take certain types of cardiovascular prescriptions, such as beta blockers, may also need a pacemaker.

How a Pacemaker Helps  

Pacemakers help patients with irregular heart rate problems by targeting different chambers of the heart and making corrections. Some slow, fast or irregular heart rates are centered around the atrium or upper chambers of the heart. 

The early models of pacemakers only corrected problems centered around the lower chambers, or ventricles. Today, modern pacemaker models are able to successfully pace both chambers of the heart. Newer models of the pacemaker can even eliminate wires, making the patient much more comfortable.

Maintenance of the ICD Device

If a doctor recommends an ICD or a pacemaker, in many cases, the device will need some sort of surgical procedure for it to be placed properly in the chest area. While many newer devices don’t require invasive surgical procedures, some devices still need to be implanted inside of the body. 

After the surgery, patients usually must stay in the hospital for one night so the medical staff can make sure the device is working properly. After the procedure, the doctor will typically have a follow-up visit a few months later to check on the patient’s heart and the device. 

Doctors may also schedule regular check-ups for the device every six months.  At some point, the batteries on the device may need replacement. For an ICD, this may be every five to seven years. A pacemaker may need new batteries every five to 15 years. Usually battery replacement requires a small surgery.

Lifestyle Changes 

People with an ICD or a pacemaker also may need to make lifestyle changes. Both of these devices may cause interference with some types of electronic equipment, so patients need to be careful when using items such as cell phones, generators, microwaves and metal detectors. 

It’s also important for patients with an ICD or a pacemaker to tell all of their health care providers about their device before treatment. Going through x-ray machines, airport security procedures and other places with a high magnetic field may also require more caution.

Improving the Prognosis

Patients who receive an ICD or pacemaker implant can improve their overall quality of life and prognosis if they also commit to a healthier lifestyle. This includes adding exercise and fitness back into the routine as long as the physician recommends it. 

Additionally, patients with an ICD or a pacemaker should also change their diet to healthier foods including fresh vegetables, fruits, whole grains and lean meats. Losing weight, avoiding air pollution and quitting smoking can also have positive impacts on the patient’s heart health and prognosis. 

Some people with an ICD suffer from  anxiety and stress anticipating when the device might deliver a shock. It’s important for patients to learn coping strategies and ways to deescalate stress so they feel more comfortable.

The defibrillator and the pacemaker have revolutionized cardiac treatment for patients with heart disease and dangerous arrhythmia. These devices are constantly being tweaked and improved to help patients live longer lives and continue to do the things they love every day.