Cardiac pacing leads play a vital role in delivering electrical impulses from an implanted cardiac pacemaker device to the heart muscle. These thin wires carry low-voltage electrical signals from the pulse generator placed just under the skin to the inside of the heart. Modern pacing systems use flexible plastic-insulated leads to stimulate the heart as needed.

Types of Pacing Leads
There are mainly two types of pacing leads - transvenous leads and epicardial leads.

Transvenous Leads
Transvenous leads are the most commonly used pacing leads today. They are inserted through a vein, usually the subclavian vein, and guided into the heart. There are three main types of transvenous leads:

- Atrial leads - Used for atrial pacing and placed into the right atrium. They have a small flexible tip to stabilize the lead.

- Ventricular leads - Placed into the right ventricle for ventricular pacing. Modern leads have retractable helical fixation screws or tines to anchor securely to the ventricular wall.

- Bipolar leads - Have two short pointed electrodes, one at the tip for stimulation and the other just behind for sensing native cardiac signals. They provide better sensing of heart activity.

Epicardial Leads
Epicardial leads are placed directly onto the outer surface of the heart during open-heart or cardiac surgery. They are used when transvenous leads cannot be placed due to venous obstruction or when temporary Cardiac Pacing Leads is needed after heart surgery. These leads have small J-shaped electrode patches sutured onto the epicardium.

Lead Placement
Proper placement of the pacing leads is important for effective cardiac stimulation and sensing. Using fluoroscopy and active fixation mechanisms, leads are guided to their intended positions.

- Atrial leads are placed high in the right atrial appendage.

- Ventricular leads are usually placed in the right ventricular apex as it provides reliable pacing and sensing. Other sites may include the right ventricular outflow tract.

- Bipolar leads have both electrodes placed close to each other to allow better signal detection.

Functions of Pacing Leads
Cardiac pacing leads perform two key functions - stimulation and sensing:

Stimulation:
The tip electrode delivers low-voltage electrical impulses from the pacemaker to stimulate the myocardium as programmed. modern leads use retractable helical screws or tines to anchor securely for reliable stimulation.

Sensing:
The sensing electrode detects intrinsic electrical cardiac activity. Bipolar leads sense signals between the two closely spaced electrodes for better signal-to-noise ratio. This helps the pacemaker determine if the heart needs pacing or not.

Lead Performance and Durability
Modern pacing leads are designed for longevity with flexible insulated construction and passive fixation mechanisms. However, certain factors like lead fractures or insulation breaks can affect performance over time. Periodic monitoring and replacement may be needed. Research continues to develop ultrasound-based wireless leadless pacing as a future alternative.

Get More Insights on this Topic- https://www.trendingwebwire.com/cardiac-pacing-leads-an-overview/