Patients suffering from certain heart rhythm disorders and heart failure may benefit from cardiac implantable electronic devices, such as pacemakers or implantable cardioverter defibrillators (ICDs).

Your heart’s rhythm will be continuously monitored after the device has been implanted. When you notice symptoms, our cardiac device team receives this information wirelessly, either automatically, through prescheduled transmissions, or manually, when you note them. You can have your heart’s electrical activity monitored remotely without ever visiting a doctor.

Pacemakers

Pacemakers fall into two categories. Electronic leads connect the device to the heart under the skin with the traditional model. No transvenous leads are required in a more miniature, leadless pacemaker placed inside the heart.

An abnormally slow heart rate – less than 60 beats per minute – is associated with bradycardia. Pacemakers help manage this condition. Pacemakers ensure a regular heartbeat by delivering electrical pulses.

How do pacemakers work?

Pulse generators, leads (sometimes more than one), and electrodes are the components of a pacemaker. Usually, pulse generators are implanted just below the collarbone. Thin insulated wires are attached to the generator and led into a vein during the procedure.

This electrode-tipped device may be placed in the upper, lower, or both of the heart’s chambers, depending on the patient’s heart condition. It is attached to the heart’s wall via the electrode.

This electrode has two functions: one, to monitor the heart rate and relay this information back to the device, and two, to take over pumping functions if the heart rate falls below a predetermined BPM threshold.

Who needs a pacemaker?

A pacemaker is usually given to patients with arrhythmias (irregular or abnormal heartbeats). A pacemaker can accelerate heart rate if it is too slow (bradycardia) or alternates between fast and slow. However, it is possible to require a pacemaker even if a patient suffers from atrial fibrillation (AF).

Catheter ablation or medication is often given to patients with AF. Unfortunately, these treatments significantly slow the heart rate of the patient. This overcorrection is stabilized with a pacemaker. Pacemakers can also be used for the following reasons:

  • Muscle deterioration due to natural aging
  • A blockage of the heart
  • Cardiomyopathy (heart failure)

Loop Recorders

A loop recorder is a wireless cardiac monitor that your electrophysiologist may recommend implanting. For up to three years, you can continuously record the rhythm of your heart with this device.

Implantable cardiac loop recorders, which are smaller than an AA battery, record heart electrical activity by being inserted beneath the skin of the upper chest. They are just like electrocardiograms or EKGs. An arrhythmia can be diagnosed by this test or identified by its cause.

This device may benefit people who suffer from unexplained fainting spells, heart palpitations, or other irregular heart rhythms that cannot be detected by short-term heart rhythm recording devices, such as Holter monitors.

Patients with atrial fibrillation, which causes rapid and irregular heartbeats, may also be recommended an implantable cardiac loop recorder. Patients with an unknown cause of stroke can also benefit from this device.

How does an implantable loop recorder work?

Heart rate can be recorded in two ways by an ILR. If the heart rate drops below a specific rate, your cardiologist will program the device to begin recording. It can be initiated by the patient as well.

To start recording, you can place a particular machine over the implantable loop recorder if you start feeling symptoms. A cardiologist has access to any recorded information, whether it was created manually or automatically. 

Who needs an implantable loop recorder?

An ILR device is typically given to patients who exhibit symptoms that might be associated with the heart, including fainting, lightheadedness, dizziness, and seizures, but whose symptoms are not frequent enough to be captured by a 24-hour to 30-day Holter monitor.

Implantable Cardioverter Defibrillators

Advanced heart failure, certain genetic diseases, and progressive heart disease can put someone at risk for life-threatening, fast, and irregular heartbeats.

An ICD is often necessary for people with these conditions, as it delivers a shock to restore a normal heart rhythm. When other treatments, such as catheter ablation or medical therapy, have not worked, an ICD may be recommended.

How Defibrillators Work?

Defibrillators come in three varieties: AEDs, ICDs, and WCDs. The different types of tests check for abnormal heart rhythms or arrhythmias. Defibrillators send a shock once they detect an irregular rhythm. Here are the three types of defibrillators and how they work.

The heart’s workings may also be understood on a rhythm check. This device helps people who experience sudden cardiac arrest. A cardiac arrest victim is fitted with electrodes and sticky pads with sensors.

Data regarding the heart rate is sent to a computer in the AED from the electrodes. The computer analyzes the heart rhythm to determine if an electric shock is necessary. An electric shock is then delivered if needed.

  • ICD: The ICD, which tests for arrhythmias, is implanted surgically in the chest or abdomen. Your heart may stop when you suffer from arrhythmia, or your blood flow may be interrupted—ICDs correct arrhythmias by sending shocks. The ICD can give off a low-energy shock to increase or decrease an abnormal heart rate, as well as a high-energy surprise to correct an irregular or fast heartbeat.
  • WCD: A WCD has skin-attached sensors. Your heart’s rhythm is checked by a wireless unit, while shocks are delivered when necessary. It can provide both low- and high-energy shocks, like an ICD. Wearing the device under your clothes is held together by a belt attached to a vest. Your doctor will measure your waist and hips to fit the device to you. The device will detect an assigned heart rhythm. Arrhythmias are detected by the sensors, and you are alerted as soon as they occur. 

Who needs Defibrillators?

SCA, or sudden and unexpected heart failure, can be prevented with an AED. Children as young as one year old can use AEDs and adults. They sometimes have special pads and cables to make the devices safe for them to use. People who suffer sudden cardiac arrest may also benefit from cardiopulmonary resuscitation or CPR. 

ICDs can treat dangerous arrhythmias or prevent sudden cardiac arrests caused by irregular heartbeats. People of all ages can suffer from life-threatening arrhythmias for various reasons. Depending on the type of arrhythmia you have, your doctor may recommend an ICD. This type of arrhythmia can cause sudden cardiac arrest.

The following conditions may require an ICD:

  • Survived a cardiac arrest.
  • A heart attack or treatment for it caused you to develop an arrhythmia.
  • Your genetics made you vulnerable to this condition. An inherited conduction disorder or congenital heart defect also falls into this category.
  • You have neuromuscular conditions. Muscular dystrophy, for example, can lead to arrhythmias and cause heart damage. Fainting can result from this, and there is a high risk of death.
  • Heart electrical signals are abnormally slow, or something else is wrong.
  • You have cardiac sarcoidosis
  • Following an operation to improve blood flow, your heart function is poor.
  • Electrocardiograms (EKGs) or stress tests detected an arrhythmia. Your risk may increase if this occurs frequently.

If you are at risk of arrhythmia for a short period, you can use a WCD to protect against sudden cardiac arrest. These conditions could lead to sudden cardiac arrest:

  • A heart attack has just occurred.
  • Your body is infected.
  • Your ICD is being removed or replaced.

References:

  • http://www.drjimenezcardiology.com/pacemaker-defibrillators-and-loop-recorder-checks retrieved on 10th December 2021.
  • https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/loop-recorder implantation#:~:text=Once%20you%20are%20diagnosed%2C%20you,or%20even%20lead%20to%20strokes retrieved on 10th December 2021.
  • http://www.phoenixheartcenter.com/pacemaker-loop-recorders/ retrieved on 10th December 2021.
  • https://nyulangone.org/conditions/cardiac-device-management-in-adults/types retrieved on 10th December 2021.