Hello welcome everybody, this is Dr. Bolad, board certified physician in cardiology,
interventional cardiology and internal medicine. I am here to help you with all the information you
need for your heart health and informing you with all the latest treatments in cardiology. If you
are new to this channel then definitely consider hitting the subscribe button below and switch on
the notification bell so you don't miss any new videos that I post. Today I will be talking to
you about heart pacemakers. A pacemaker is a small electronic device that generates electrical pulses
to prompt the heart to beat at a normal rate. It is usually placed in the upper part of the chest
under the skin and more recently a new line of pacemakers are implanted directly into
the heart chamber through catheters. Pacemakers are implanted in patients with slow heart rate
due to heart conduction abnormality that leads to symptoms such as dizziness, lightheadedness,
syncope, fatigue and poor exercise tolerance when it is determined that there are no reversible
causes leading to the slow heart rate. As you can see, first the patient is brought to the operating
room initially a contrast is sometimes injected to visualize the subclavian and axillary veins
as shown here. Then the cardiologist perform a skin incision in the chest under the collar
bone. The skin incision is then deepend and the incision kept open using a retractor. Then
the cardiologist gets access to a large vein generally the subclavian vein using a needle.
This is how it looks like on the x-ray. Through that needle a wire is passed and on top of that
wire a sheath is passed. Through the sheath, the pacemaker wires are passed and attached to the
heart as shown in these images. A chest X-Ray is then performed to make sure that the wires are in
place and that there are no obvious complications such as pneumothorax, which is air leakage outside
of the lung. Pacemakers have two components, a pulse generator which provides the electrical
pulses for the heart muscle stimulation, and one or more leads that delivers the electrical
impulse from the pulse generator to the heart. The pulse generator is the battery component of the
pacemaker generating the electrical impulse which is transmitted to the heart muscle resulting in
the heart beat. The pulse generators are commonly implanted in the infra-clavicular region of the
anterior chest wall. The impulses generated are transmitted to the heart muscles through the leads
which are placed through a large vein that leads to the heart. These transvenous leads
can be associated with long-term complications such as infection, clot formation on them,
lead malfunction and injury the tricuspid valve. A variant of this type of pacemakers is known as
epicardial pacemaker system. The system utilizes a pulse generator with leads that are surgically
attached directly to the outer surface of the heart. This type of pacemaker system is
used in a small percentage of patients that need pacemakers when there are issues with the veins
or the tricuspid valve. It is a larger surgery and that is why it is not routinely utilized.
Recently a lead-less system of pacemakers have been introduced in response to the limitations of
both trans venous and epicardial pacing systems. This is a small self-contained system as shown
in this figure and it includes both the pulse generator and the electrodes within a single unit.
That is placed into the right ventricle via a transvenous approach using catheters as shown
in this figure. The device is delivered to the right ventricle and secured in place there. This
is a new technology and is showing promise to be used more widely in the future. Apart from
the slow heart rate due to conduction abnormality leading to symptoms, pacemakers are also implanted
in patients with neurally mediated syncope a disorder of the autonomic nervous system which
results in a drop in blood pressure and slow heart rate and loss of consciousness. A wide variety of
stimuli can trigger this reflex, the most common stimulus being orthostatic stress. Secondly,
neuromuscular diseases these are disorders of the peripheral nervous system which consists of all
the motor and sensory nerves that connect the brain and spinal cord to the rest of the body.
Thirdly, long QT syndromes. These are high risk patients with long QT duration on the ECG
and are treated with pacemakers to prevent dangerous irregularity of their heart
rhythm. Forthly, Hypertrophic Cardiomyopathy patients, a condition associated with
abnormal thickening of the heart muscle. These patients can also develop serious irregularity
of heart rhythm and pacemakers and defibrillators are recommended. Finally, heart failure patients
in whom the heart is enlarged as shown on the chest x-ray here and outlined by the orange line
across the image. A special type of pacing known as cardiac rhythm resynchronization therapy CRT,
also referred to as biventricular pacing, is used to improve symptoms and survival in patients with
advanced heart failure. For many decades, follow-up evaluation of pacemakers required
an in-person assessment for device interrogation on recurring basis. However with the progress of
technology, most current pacemakers can get comprehensive and safe remote monitoring.
Remote monitoring provides alerts in real time but is not as comprehensive as in-person complete
device interrogation. The current recommendations is that in addition to remote monitoring,
the pacemaker should be checked in the doctor's office or hospital at least once a year. If you
have any question about what I presented to you today or any cardiology question in general, then
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this is Dr. Bolad helping you with your heart health, thanks for watching and talk to you soon.