Text
Descriptions of Medical Devices Pictures
Angioplasty Device
Illustration of a narrowed artery being opened with an angioplasty
device. The following illustrations step through the processes
of angiography and angioplasty.
Angioplasty is a procedure used to open arteries narrowed
by atherosclerosis. To find the blockage, the coronary arteries
need to be x-rayed. This process is called angiography. In
angiography, a guidewire is inserted through an artery in
the arm or leg. From there it is fed through the aorta and
into position. A catheter is then inserted along the guidewire
and dye is injected into the blood vessels. The dye will show
up white in an x-ray image. As the vessels are illuminated,
areas of narrowing, or stenosis, reveal blockage.
In angioplasty, a balloon catheter follows a guidewire into
the blocked coronary artery. The balloon is inflated and pushes
the plaque up against the artery walls. The balloon is deflated,
and the balloon catheter and guidewire are removed. The final
illustration shows the angioplasty process completed with
the blood vessel opened.
[Back]
Cardiac Ablation Catheter
Illustration of electrical conduction in the heart. Cardiac
ablation is a procedure that is used to correct irregular
heartbeats by destroying cardiac tissue that creates abnormal
electrical signals. A second illustration shows a cardiac
ablation catheter advancing into the heart and destroying
cardiac tissue.
[Back]
Implantable Cardioverter Defibrillator
(ICD)
Illustration of an ICD implanted near the shoulder, with
lead wires connected to the heart. When the ICD senses an
abnormal heart rhythm, it delivers an electrical shock to
reset the heart rhythm to a normal rhythm.
[Back]
Pacemaker
Illustration of a pacemaker implanted near the shoulder,
with a lead wire connected to the heart. Subsequent illustrations
show single lead and dual lead pacemakers.
A cardiac pacemaker is an implantable device that is used
to regulate and maintain a normal heartbeat. It is used to
treat conditions such as bradycardia and AV block.
A single lead pacemaker delivers electrical signals to the
ventricle. A dual lead pacemaker delivers electrical signals
to the atrium and ventricle.
[Back]
Prosthetic Heart Valve
This series of illustrations begins by showing a mechanical
prosthetic heart valve and a bioprosthetic (tissue) heart
valve side by side. It then shows the way that healthy heart
valves and diseased heart valves function. Finally, it shows
a mechanical heart valve replacing a diseased mitral valve.
Healthy heart valves open and shut when the heart contracts
and relaxes. They prevent blood from flowing backwards through
the heart. Heart valve disease causes the valve to become
too narrow, or leak. This allows blood to flow backward through
the heart. The diseased valve can be replaced with a prosthetic
heart valve, restoring valve function.
[Back]
Stent
Illustration of a blood vessel narrowed by atherosclerosis
being opened by angioplasty and then held open with a stent.
To insert a stent, a guidewire is threaded to the site of
narrowing in the artery. A balloon catheter with a collapsed
stent is placed in the narrowed artery. The balloon is inflated,
expanding the balloon and pushing the plaque up against the
artery walls. Then, the balloon catheter is deflated, leaving
the stent in place to hold the artery open. The catheter and
guidewire are removed.
Over time, plaque can reform around the stent. Drug-eluting
stents contain a time-releasing drug that can prevent in-stent
restenosis.
[Back]
Ventricular Assist Device
Illustration of a torso with a left ventricular assist device
implanted. A ventricular assist device is used to help a heart
that can no longer pump blood effectively due to heart failure.
The power pump and controller are located outside the body;
the pump may be either implanted or external. The left ventricular
assist device removes blood from the left ventricle and then
pumps it to the aorta so blood can reach the rest of the body.
[Back]
|