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Pacemaker is a device that is used to send small electrical impulses to the heart muscle to keep the heart rate regulated or to stimulate the lower chambers of the heart (ventricles). It can also be used to treat fainting spells (syncope), congestive heart failure, and hypertrophic cardiomyopathy.
These are implanted to help control the heartbeat. They are sometimes implanted temporarily to treat a slow heartbeat after a heart attack, surgery, or medication overdose. While other times, they are implanted permanently to correct a slow or irregular heartbeat, or in some people, to help treat heart failure.
Evolution of Pacemakers
After the introduction of a temporary transcutaneous cardiac pacing by Paul Zoll in the year 1952, the first definitive electronic pacemaker was implanted by Senning and Elmqvist in Sweden on October 8 1958, using a thoracotomy to suture two epicardial electrodes. The early form of pacemakers had the potential to pace the ventricles asynchronously, not having the capability to sense the electrocardiogram. In the latter form of devices, which comprised of demand mode pacemakers, they had the potential to sense the amplifier which had calculated the cardiac activity, thereby avoiding any competition between the paced and intrinsic rhythms of the heart. After that, in the year 1963, such pacemakers were constructed that had the ability to bring about the ventricular synchronization in sync with the atrial activation.
Various components of a Pacemaker
The pacemakers are composed of an implantable pulse generator that is attached to an electrical battery and one or two pacing leads. The IPG allows the generation of electric current that is required for stimulation of the myocardium. The current that is to be delivered to the myocardium through the leads are guided to the right atrial or the ventricular myocardium via a vein.
The pacemaker is placed under the clavicle between the skin and the pectoralis major. The IPG shell is usually made of titanium which is well tolerated by the surrounding biological environment.
A Pacemaker battery is used to deliver pacing pulses, sensing (analyzing the electrical activity in the heart), and storing electrocardiograms. The pacemaker is powered by a lithium battery which is built to last for 5–10 years.
Pacemaker Leads and Electrodes
The leads of the pacemaker contain conductors wrapped in insulation. The majority of the pacemakers make use of bipolar pacing, where the lead tip is equipped with two electrodes – anode and cathode. Voltage is applied between the two electrodes with the help of the pulse generator, which results in the flow of electrons.
Working of the pacemakers
The pacemaker tends to deliver an electrical impulse with the proper intensity to the proper location in order to cause stimulation of the heart at the desired rate. The working of the pacemaker is explained as follows:
- The pulse generator is composed of electrical components that can generate an electric pulse at a proper time based on the sensed events. Impulses are transmitted to the heart using a lead, which is attached to the pulse generator via the connector block.
- A lead is either unipolar or bipolar; a unipolar lead contains one insulated coil, whereas a bipolar lead contains two coils, separated by inner insulation. The tip of a lead contains an electrode and is implanted into the inner, endocardial surface of the heart; the actual location depends on the type of pacemaker.
- A pacemaker is programed through a programmer, a computer with a unique user interface for data entry and display, and special software to communicate with the pacemaker. The telemetry head is placed above the pacemaker’s location; information from the programmer to the pacemaker and back is transmitted utilizing telemetry.
Applications of Pacemakers
A Pacemaker is an electrically charged medical device. The surgeon implants the pacemaker under the skin to manage irregular heartbeats of the patients, also known as arrhythmias. The pacemakers are generally used to treat two types of arrhythmias: Tachycardia (too fast a heartbeat) and Bradycardia (too slow a heartbeat).
When an arrhythmia or atrial fibrillations occurs, the heart’s native atrial activity causes the atrial sensing, which triggers the ventricular pacing at the pacemakers maximal preprogrammed rate. The main purpose of a dual-chambered pacemaker is to achieve atrioventricular synchrony. The atrial lead sensing atrial depolarization can be achieved by triggering the ventricular lead to depolarize the ventricle after some atrioventricular delay. Other types of patients also require a biventricular pacemaker, also known as bivent in case they are suffering from severe heart failure. A bivent tends to make the two side so of the heartbeat in sync. This is also known as cardiac resynchronization therapy.
Recent Developments in the Pacemakers Pipeline
- On April 16, 2021, Medtronic partners with cybersecurity startup Sternum to protect its pacemakers from hackers (TechCrunch, 2021).
- On July 3, 2020, MicroPort Scientific Corporation announced that MicroPort Cardiac Rhythm Management Limited, MicroPort’s subsidiary, has entered into definitive agreements in connection with its Series B financing with total investment proceeds of USD 105 million. GL Ventures, the venture capital arm of Hillhouse Capital Group, will lead the Series B investment and will invest USD 50 million.
- On April 30, 2018, MicroPort Scientific Corporation announced the closing of the transaction to acquire the Cardiac Rhythm Management business from LivaNova PLC. After the complete acquisition, the acquired CRM Business was officially rebranded as MicroPort® CRM (MicroPort Scientific Corporation, 2018).
A Pacemaker is a device that tends to regulate the electrical system of the body; it helps in controlling the rhythm of the heart. It is usually implanted under the skin in order to manage arrhythmias. Patients that die of arrhythmia are assumed to be approximately between 2 00,000 to 300,000 per year. After the introduction of a temporary transcutaneous cardiac pacing by Paul Zoll in the year 1952, the first definitive electronic pacemaker was implanted by Senning and Elmqvist in Sweden on October 8 1958, using a thoracotomy to suture two epicardial electrodes. Since then, Pacemaker technology has evolved considerably over the past decade and the companies and researchers that are being performed are now trying to offer features that is trying to fulfil the patient’s individual physiologic needs. According to a research article by (Hao et al., 2015), there are more than 3 million functioning permanent pacemakers and about 600,000 pacemakers that are implanted each year worldwide.
The devices that are now available in the Pacemakers market comprise pacemakers that are able to track device data and patient health with the help of remote monitoring systems such as Azurea with BlueSync Technology by Medtronic. The modern pacemakers are very small in sizes and are safe for Magnetic Resonance Imaging exams take for example ENO Pacemaker by company Microport CRM and Accolade family of pacemakers by Boston Scientific Corporation.
They comprise batteries that have a longer life span and technology to help reduce pacing requirements to conserve battery power. Apart from these, the devices can easily store any new data which is capable of providing more information on patient health and device status. Lastly, the devices available are single-chamber, transcatheter-delivered, leadless pacemaker systems, which make them an efficient tool for implantation within the patients. These devices do not require extensive forms of surgeries and can be delivered via minimally invasive procedures. Leadless pacemakers are a remarkable development in miniaturization and may well be the future of the pacemaker industry.
The biological form of Pacemakers is again considered as an exceptionally useful development and is being researched continuously in pre-clinical and clinical stages and is expected to get commercialized in the near future. These form of pacemakers are found to have multi-directional benefits for both patients and clinicians. The surgeons have to devote a major chunk of their time to fitting replacements within the patients. The biological pacemakers developed from the embryonic stem cells offer no immune responses, require no device replacement and do not indulge in any device or lead failure issues.
With an increase in the technological developments progressing around the globe, it can be well thought that the advancements taking place in terms of energy generation and restoration, delivery, size, among various other parameters, will be unimaginable.
According to Delveinsight’s Pacemakers market estimates, 90% of the Pacemaker devices available in the market are implantable, whereas only 10% of the pacemaker devices can be used externally. However, for the products that continue to be in the Pacemaker Pipeline stage, 75% of these pacemaker devices are intended for use internally among patients, whereas only 25% of pacemaker devices can be used externally.
As per the estimates of Delveinsight, there is a huge scope of growth in the Pacemaker market, comprising 92% of the devices that are currently in the marketed stage. The Pacemaker Pipeline devices currently are lesser in comparison, but continuous research and development will ramp up the number of pipeline devices in the near future.
Future of Pacemakers
Leadless pacemakers have been developed in order to take care of the disadvantages that were offered by the lead pacemakers. In leadless pacemakers, the pulse generator, the battery, and the sensing and pacing electrodes are self-contained in a small capsule designed to be delivered into the right ventricle through a steerable sheath inserted through the femoral vein. An example of Leadless Pacemakers is the Micra AV device designed by Medtronic.
Biological pacemakers are being constructed and researched so that they can provide a therapeutic alternative to electronic devices. Different biological approaches have been investigated over the years in order to enhance cardiac automacity. The common goal is to generate an ectopic region of automaticity in the heart that can function as a surrogate for the sinoatrial node (SAN). An example of a biological pacemaker that is currently in the pipeline is the biological form of pacemaker that is being constructed by Biopace Inc. for pediatric patients.