Pacemaker Insertions

Pacemaker
A pacemaker is a small device that's placed under the skin of your chest or abdomen to help control abnormal heart rhythms. This device uses electrical pulses to prompt the heart to beat at a normal rate. Pacemakers are used to treat heart rhythms that are too slow. These abnormal heart rhythms are called arrhythmias .
The following will tell you how a pacemaker treats arrhythmias. It also talks about activities that you still can do and those you should stay away from.

Hearts Natural Pacemaker
The heart has its own electrical system that controls the speed and the rhythm of every heartbeat. With each heartbeat, an electrical signal spreads from the top of the heart to the bottom. As it travels, the electrical signal causes the heart to contract in an organized manner and pump blood.

FIGURE 1: The heart and its blood flow

Electrical signals normally begin in a group of cells called the sinus-atrial (SA) node. As these signals spread from the top to the bottom of the heart, they coordinate the timing of heart cell activity. First, the two upper chambers of the heart, called atria contract. This contraction squeezes blood into the lower chambers of the heart, which are called ventricles. The ventricles then contract and send blood to the rest of the body. The combined contraction of the atria and ventricles is a heartbeat.
Sometimes the heart beats too slowly (Bradycardia). During Bradycardia, enough blood is not supplied to the body, due to failure of the hearts chambers to contract properly.This could happen due to SA node not functioning properly, or by a condition called heart block. In this condition, a problem exists with the electrical pathway between atria and ventricles. Electrical signal sent out by the SA node, may not reach the ventricles or is delayed.

FIGURE 2: An example showing heart block

Faulty electrical signaling in the heart causes arrhythmias. A pacemaker uses low-energy electrical pulses to correct faulty electrical signaling. Pacemakers can speed up a slow heartbeat,
Make sure the ventricles contract normally if the atria are quivering instead of beating in a normal rhythm (a condition called atrial fibrillation). Pacemakers can also coordinate the electrical signaling between the upper and lower chambers of the heart.

Pacemaker Systems 
A pacemaker system monitors and treats the abnormal heart rhythm. Pacemakers can be temporary or permanent. Temporary pacemakers are used in emergency settings, or when the underlying cause of the abnormal heart beat is expected to resolve itself. They are also used to re-establish a normal heart rhythm until a permanent pacemaker is installed. Temporary pacing may be required among heart attack patients, severely symptomatic patients with Bradycardia, patients with Tachycardia, after open-heart surgery and other settings. A person with a temporary pacemaker will stay in the hospital as long as the pacemaker is in place.

In this article, "pacemakers" refers to permanent devices, unless stated otherwise. A permanent pacemaker is used when slow heart rate becomes chronic. A permanent system consists of a pulse generator (also called a device), which is implanted on your chest. One or more leads which is implanted in the chambers of your heart (Atrial or ventricle), are connected to the device.

FIGURE3: Placement of pacemaker leads

The Generator

      Pacemaker Device

The generator is a small computer which runs on a battery, safely concealed the devices case. The device continuously monitors your heart functions and delivers electrical energy (charge) to pace your heart when it senses a slow rhythm. Together with monitoring your heart rhythm a device can also store information about your heart. The doctor than can review this information using a small computer called programmer. This helps the doctor better assess the heart rhythm and determined weather the programmed treatment is appropriate. If necessary the devices setting can be changed with the programmer.

The Leads

A pacemaker lead is an insulated wire connected to the pulse generator and implanted in your heart. Heart signal is carried via a lead to the pulse generator  which then carries energy from the pulse generator back to the heart to coordinate your heart rhythm as the need arises.

Types of Pacemakers
There are two types of pacemakers available: single chamber and Dual chamber. Your cardiologist will discuss with you which kind of pacemaker is appropriate for you.

Single-chamber Pacemakers
A single chamber pacemaker typically uses one lead placed either in the right atrium or right ventricle to pace the heart. This type of pacemaker is often selected for a person whose SA node sends out signals too slowly.

Dual-chamber Pacemakers
Dual chamber pacemakers typically use two leads, one placed in the right atrium and the second one placed in the right ventricle. The electrical pulses delivered to the heart are timed so that the atria are stimulated to contract just before the ventricles. The timing ensures the atria and the ventricles are beating "in sync" with one another.

A dual chamber pacemaker can be selected for many different reasons. For some, SA node signals are too slow and electrical pathway to the ventricles gets partially or completely blocked. And for others, the timing of the Atria and Ventricle contractions are uncoordinated (asynchronous).

Pacemaker Implantation
During pacemaker insertion, the doctor makes a small insertion near your collar bone, to gain access to the vein. The pacemaker lead is then inserted into the vein, into the heart, where the tip of the lead rests directly against the heart’s inner wall.

FIGURE 4: A single chamber pacemaker insertion

Should the cardiologist decide, that the presenting symptoms require a Dual-chamber pacing, another lead will be implanted. One lead is positioned in the atrial chamber and the other in the ventricular chamber (Figure 5). After the leads are correctly positioned, the device and the leads are tested to determine correct functionality. After the testing the device is then placed in position, which is usually below the collarbone, just underneath the skin and incision in the closed with sutures.

FIGURE 5: A dual chamber pacemaker

Risks
Your doctor will go through the risks associated with this procedure before consent is signed. Unlike any surgical procedure, pacemaker insertion also can cause post  implant adverse events such as: chronic nerve damage, erosion, fluid accumulation, formation of hematomas or cysts, infection, pneumothorax,  lead dislodgement and/or interference that prevents the device from pacing.

Post Procedure
As you recover, you will find that your pacemaker may allow you to return back to active lifestyle. However it is important to follow your doctor’s instructions in order to avoid any unnecessary complications.

• Report any redness, swelling or drainage from your incisions.
• Avoid lifting any heavy objects until instructed by your doctor.
• Walk, exercise, and bathe accordingly as instructed by the cardiologists.
• Avoid wearing tight clothes that could irritate the skin over your device.
• Contact your doctor if you develop fever that doesn’t go away in two or three days.
• Avoid rubbing the device or the surrounding chest area.
• If directed by your doctor, limit arm movements that could limit your affect your lead system
• Tell your other doctors, dentists, and emergency personnel that you have a pacemaker.
• Contact your doctor if you notice anything unusual or unexpected, such as new symptoms, or  symptoms like the ones experienced before getting pacemaker insertion.

Medications
It is important to discuss with your doctor instructions regarding any medications.

Activities and Exercise
The doctors will help you what level of activities suited for you therefore answering your questions regarding lifestyle changes, travel exercise, work, hobbies and resuming sexual intimacy.

Follow-up Visits
The pacemaker will automatically monitor and treat your heart rhythm. It is important to follow the doctor’s instruction and keep up with your scheduled follow-up appointments even if you are feeling well. The pacemaker contains many programmable features and keeping your appointments can help your doctor programme the Pacemaker to best meet your individual needs.

A programmer is a small computer which communicates with the pacemaker outside the body, through a wand which is placed over the skin.

Pacemaker Battery
Pacemaker uses battery energy to monitor and pace the heart rhythms as needed. Pacemaker battery is safely sealed inside the device, and just like any other battery operated device, the pacemaker battery also gets used up over time. Battery life depends upon the setting that has been used to programme the device and a number of pacing therapies given. At every follow-up visits the doctor or nurse checks the battery life and when the battery energy decreases, the device needs to be replaced.

Replacing the Device
The doctor will surgically open the pocket of skin where the device is located. The old pacemaker is disconnected from the leads. The leads are tested to ascertain proper functionality. The leads are then connected to the new pacemaker. Final tests are carried out to make sure the pacemaker is working properly before suturing the pocket of the skin. Replacing the device is considered minor operation and normal activities can be resumed soon.

Video Demonstration

 Life with your Pacemaker