Micra Transcatheter Pacing System: A Revolutionary Leadless Pacemaker Technology

Introduction:

Pacemakers are devices that are placed in the human body to help control the heartbeat, in other ways having an irregular heart rhythm. It helps to generate electrical impulses and support the heart in everyday functioning. These are small battery-operated devices.

What Is the Micra Transcatheter Pacing System?

The technology used in cardiac pacemakers is called pacing technology. The advancements include

• Miniaturization of the design.

• Low power usage.

• Improvements in battery life.

• Longevity of the pacemaker.

• Communication protocols minimize power consumption.

• Safe affixation of the catheter-based delivery tools to the heart wall.

Also called TPS is the smallest pacemaker in the world, which is about 1.019685 inches in length and volume of 0.000211338 US liquid gallons. The weight of the micra-pacing system is only 0.07 ounces. This smallest pacing system can be implanted directly into the heart and eliminates the need for leads. The procedure is minimally invasive, implanted through a catheter in the leg. This procedure does not require any chest incision.

Micra TPS is a leadless pacemaker that does not need any separate battery or leads(wires). The device is placed in the right ventricle. Healthcare professionals can customize the device and can send small electrical signals. Impulses when needed. It can sense and provide additional electrical stimulation when needed.

The fixation mechanism is by nitinol tines. The sensor is an accelerometer. It has two ends, a cathode, and an anode. The cathode is steroid-eluting and has anti-inflammatory action. The nitinol tine design pulls the micra cathode into contact and returns to the original place.

What Are the Indications for Micra TPS?

• Atrial fibrillation.

• Complete heart block.

• Brady-tachycardia syndrome, where there are episodes of both slow and fast heartbeats.

• Sick sinus syndrome, which is a heart rhythm disorder affecting the sinoatrial node (SA node)

• Sinus arrest with infrequent syncope.

• Coronary artery diseases.

• Symptomatic paroxysmal or permanent high-grade atrioventricular block with atrial fibrillation.

• Permanent high-grade atrioventricular block without atrial fibrillation.

• Bradycardia is a common arrhythmia disorder where the heartbeat is less than 60 beats per minute.

• Alternative for dual chamber pacing.

• In patients where the atrial lead placement is a high-risk procedure.

• Sinus node dysfunction.

How Is It Implanted?

• It is a single-chamber ventricular pacemaker.

• The Micra TPS system is attached to a steerable catheter delivery system, and the catheter is inserted into the femoral vein.

• The delivery system is slowly advanced into the right ventricle of the heart and fixed to the myocardium.

• The device is implanted with the help of four electrically inactive nitinol tinea at the distal end of the device.

• The electrical measurement results are checked.

• If the electrical measurement is not achieved, then the position is changed. Still, the device is connected to the delivery system.

• The optimal position is confirmed by injecting radiographic contrast.

• After testing the electrical threshold and stability, the delivery system is removed.

• Vascular access sites closed with absorbable double sutures.

• Patients can leave the hospital after one day of pacemaker placement and can start all the day-to-day activities after seven days.

What Are the Advantages and Salient Features of Micra TPS?

Advantages:

• Minimally invasive procedure where no chest incision is made.

• Self-contained, directly placed into the heart.

• Smaller size than conventional pacemakers.

• Can undergo MRIs safely.

• Automatically senses changes in the body.

• Battery life of 12 years.

Salient Features:

• Success Rate: The high success rate of micra pacemaker implantation is 95 to 100 percent.

• Safety: Benefits of reducing the acute complications associated with traditional pacemakers.

• Use in Elderly and Comorbid Patients: The Micra pacemakers were more utilized for elderly patients and comorbid patients.

• Long-Term Electrical Performance: It was approved in 2016 by FDA and followed up till the year 2022. This can be used for up to 12 years. Ongoing stability and shorter pulse width are other features.

• Cost-effectiveness: Cost is another major consideration among patients. Leadless pacemakers are about four times more costly than transvenous single-chamber pacemakers. The cost-effective pacemakers will be made available in the future without compromising the qualities of Micra TPS.

• Valvular Function: Transvenous pacemakers are associated with an increased risk of tricuspid valve regurgitation. This can lead to heart failure and mortality. To avoid such complications, implants used must be leadless pacemakers. It avoids direct impingement on the tricuspid valves.

What Are the Problems Associated With Micra TPS?

The leadless pacemaker can be used to pace only one ventricle. Following the implantation of the pacemaker, swelling and bleeding at the incision site is a possible defect associated. These can prolong the hospital stay and slower recovery. Higher cost than traditional pacemakers.

Other serious complications can sometimes be the device moving out and internal bleeding, which is called cardiac tamponade or pericardial effusion.

What Are the Complications of Traditional Pacemakers?

A pacemaker has one or two leads connected to a device, implanted into a pocket created under the collarbone. It is placed subcutaneously.

Significant complications were reported, and the presence of lead in traditional pacemakers has created lead-related problems and pocket-related problems, which include the following. Long-term communications are related to lead failure, which is the weakest part of the pacemaker system.

Lead-Related Complications:

• Pneumothorax (collection of air in the pleural cavity of the lungs).

• Cardiac perforation (rare complication of the pacemaker implant system).

• Lead dislodgement (can lead to malfunctioning of the pacemaker system).

• Venous thrombosis (blood clots formed inside the deep veins in the body).

• Obstruction of branches superior vena cava (obstruction of blood flow in the largest vein).

• Regurgitation of tricuspid valves and infections (the flaps of the hot wall do not close properly).

Pocket-Related Complications:

• Hematoma (results in a pool of clotted blood in tissues).

• Skin erosion (incomplete loss of epidermal layer of skin).

• Life-threatening infections lead to the removal of the pacemaker.

What Are the Instructions the Patients Must Follow After Receiving a Micra TPS?

• Following the procedure, some may feel pain or discomfort at the puncture site. If it aggregates or last longer, consult with the doctor.

• Support the puncture site for the first 48 hours

• Avoid strenuous exercises and lifting heavy objects.

• Proper dressing at the puncture site.

• Avoid hot baths for about three days.

• Avoid drinking alcohol.

Conclusion:

Studies on people with micra pacemakers have showed effective and safe functioning.The safety and efficacy of the pacemaker were reported with short-term and long-term use of the pacemaker. It was proved to be the best alternative for the transvenous pacemakers. This type of leadless pacemaker requires minimally invasive procedures and a short hospital stay after implantation. The benefits of Micra TPS are more when compared with the disadvantages. Only the cost associated is a little bit higher, and hope to get economically feasible pacemakers in the future without compromising the quality.