Permanent Pacemaker (PPM) for bradycardia
Introduction
What is it?
Pacemakers provides pulses of electrical current to your heart to keep it beating regularly. If the heart rate is too slow (called bradycardia) and you are getting symptoms then pacemaker insertion should be considered.
Initially pacemakers simply generated repeating pulses but modern pacemakers can sense the underlying rhythm of the heart and give out electrical pulses as and when necessary.
Pacemakers have a number of features which should be explained.
Demand Pacing
The first generation of pacemakers fired electric currents continuously, this wasted battery life and also resulted in the pacemaker firing during the sensitive T wave phase of the heart electrical cycle.
Demand pacing allows the pacemaker to be silent while the heart is generating its own rhythm and only cut in when needed.
Programmability
Pacemakers can now be altered after they are fitted into a persons. Programming devices allow for the rate and pacing threshold to be altered as well as checking the integrity of the leads.
A function called hysteresis is also programmed in. This allows for a longer pause than the set pace rate before the pacemaker cuts in. This gives more of an opportunity for the heart rhythm to cut in, extending battery life.
Rate Response
Modern pacemakers are able to sense activity of the person fitted and adjust the pace rate according to the demand on the heart.
Pacemaker Memory
Pacemakers can store data on how often they needed to fire and also activity levels of the patient. It is possible to also record when arrhythmias or runs of irregular heart rate occur.
Pacemaker terminology
Pacemaker functionality is described by a series of letter. The position of the letter in a list is determined by this order:
1. Which heart chamber is paced (0, Atrium, Ventricle or Dual)
2. From which heart chamber is activity sensed (0, Atrium, Ventricle or Dual)
3. What is the response to sensing (0, Triggered, Inhibited or Dual)
4. Rate modulation (0, Rate modulation)
5. Multi-site pacing function (complex function used for cardiac resynchronisation therapy).
Common types of Pacemaker
VVI
This type has a single lead inserted into the right ventricle. The pacing is on demand as sensed heart rhythm inhibits (stops) pacemaker activity.
VVIR
This is the same as the VVI pacemaker but has a rate response feature which can adjust output according to activity level.
DDD
This is a complicated device with leads in the atrium and ventricle. Both chambers of the heart are paced to more closely copy the normal heart electrical function.
DDDR
This is the same as the DDD pacemaker but with rate response to adjust output rate according to activity level.
Why is it done?
1 Symptomatic sinus bradycardia Intermittent prolonged sinus pauses (more than 3 seconds) resulting in syncope (collapse) or pre-syncope. 2 Sick Sinus Syndrome This is a condition where the heart alternates between episodes of atrial arrhythmias (arrhythmia originating from the atria chamber of the heart), such as atrial fibrillation or flutter and bradycardias (slowing of the heart) or long pauses of the heart rhythm. 3 Heart block First degree – Pacing is only indicated if the patient has symptoms, or where persistent first- degree block is causing a problem to the patient. Second-degree heart block – These are further divided into two categories: Mobitz type-I (Wenkebach) block rarely requires pacing. Mobitz type-II block requires pacing. Acquired third-degree heart block. Congenital third-degree heart block – these patients usually do not have symptoms but pacemaker is advised over the age of 50 years, irrespective of symptoms. 4 Carotid sinus hypersensitivity/ reflex syncope. This is a syndrome where you get recurrent syncope (collapse)/pre-syncope with a long sinus pause (in excess of 5 seconds) in heart rhythm during carotid sinus massage.
Will I need to do any preparation?
No specific preparation is needed for the procedure.
Technique
Anaesthesia
The procedure is done under local anaesthetic
What does it involve?
An incision about 2 inches long is made just beneath the left collar bone. The subclavian vein is found through which leads are passed into the heart. The leads are positioned within the heart under x-ray vision and then the electrical connections are checked. The leads are stitched in place and the pacemaker box (about the size of a cigarette lighter) is attached to the leads.
A pocket in the flesh beneath the incision is made and the pacemaker is placed inside and closed up with a stitch.
This is all done in a specially equipped operating room, with x-ray equipment and with sterile drapes over you. The team around you are friendly and there to help you, and I can give you medication to make you sleepy and more comfortable if you would like or need it.
Following the procedure, you will have X-rays taken to confirm the portion of the pacemaker device and also that of the pacemaker leads.
How long does it take?
The procedure takes around an hour to complete.
Post procedure course (follow-up)
From time to time we will need you to attend our pacing clinic and we interrogate the device automatically through the skin and it tells us the condition of the device, how much battery life there is remaining and the condition of the leads, and can re-programme the device as necessary to get the best from your heart function. Essentially, the way a pacemaker works is that it just sits there watching over you and puts in an extra heart beat if you need it, if you naturally have a tendency to go too slow.
The battery life on these devices last about 10 years depending on how much it is required to be active, and when it is time to replace it we simply reopen the pocket, take out the device, disconnect it from the leads and replace the whole box.
The leads themselves are very delicate but have to function and bend with the beating of the heart 100,000 a day and so deteriorate with time and just sometimes there are problems with the leads which we detect and there is a need to replace them.
Pacemaker devices and cordless phones these days are all very well shielded but we do recommend not having your mobile phone in a breast pocket immediately overlying the device. It used to be recommended that you use your phone to the opposite ear, but this is not really necessary.
How long will I stay in hospital?
You should plan on going home the following day, although sometimes I can let you home the same evening as the procedure.
You will have some discomfort at and around the wound, that usually responds well to simple pain-killers like paracetomol. You will get bruising around the wound and there may be some fluid collect in the pocket around the pacemaker over the first few hours or days but this usually requires very little action and eventually goes down on its own.
In the days after the procedure, you should keep the shoulder moving on the side of the procedure but not to lift the elbow above the shoulder in any direction and avoid heavy lifting with that arm for perhaps 2 weeks. I will then see you about a week after the procedure to inspect the wound and remove the suture.
What care will I need at home?
No particular care is required at home.
Will I need someone to stay with me?
If you have had sedation, you may feel a little drowsy, it may be helpful to go home with someone.
Will I need someone to stay with me?
If you have had sedation, may be helpful.
Will I need any special equipment when I go home?
No
What follow up care is needed?
You will have follow up in a pacemaker clinic initially an then at regular intervals to check the functioning of the pacemaker. The pacemaker may need to be changed when the battery wears out which can be up to 10 years. Occasionally the leads connecting the pacemaker to the heart get fractured and need to be changed.
When can I start my normal activities again (e.g. driving, sports or work?)
At time of writing the DVLA recommend the following: Must not drive for at least 1 week but
need not notify the DVLA. Driving may resume after 1 week provided there is no other disqualifying condition. See https://www.gov.uk/guidance/cardiovascular-disorders-assessing-fitness-to-drive for up to date guidelines.
