47 / 56
Chapter 2
•
Cardiovascular Care
59
Percutaneous Transluminal
Coronary Angioplasty
Percutaneous transluminal
coronary angioplasty (PTCA), also
called
angioplasty,
is a nonsurgical
alternative to CABG. Performed in
the cardiac catheterization laboratory
under local anesthesia, it involves the
use of a balloon-tipped catheter to
dilate the blocked coronary artery. In
most cases, the patients recuperate
quickly, usually walking the same day
and returning to work in 2 weeks.
PTCA works best when lesions are
readily accessible, noncalcified, less
than 10 mm, concentric, discrete,
and smoothly tapered. Possible
complications include vessel closure
and late atherosclerosis.
Understanding PTCA
In PTCA, a guide catheter is threaded into the coronary artery by way of
the femoral artery. Then, a balloon-tipped catheter is inserted through the
occlusion and inflated to flatten the plaque until the vessel is opened.
Wall of
coronary
artery
Plaque
Catheter in
place; balloon
deflated
Balloon
inflated
Plaque
flattened;
catheter
removed
Dashed lines
indicate
old plaque
thickness
Catheter
Radiofrequency Ablation
Radiofrequency ablation is used to
treat arrhythmias in patients who
do not respond to antiarrhythmic
drugs or cardioversion. During
the procedure, a special catheter
is inserted in a vein and advanced
to the heart. After the source
of the arrhythmia is identified,
radiofrequency energy destroys the
abnormal electrical impulses or
conduction pathway. The tissue that
is destroyed can no longer conduct
electrical impulses.
AV NODE ABLATION
If a rapid arrhythmia originates
above the AV node, the AV node
may be destroyed to block impulses
from reaching the ventricles.
Sinoatrial
(SA) node
Radio-
frequency
catheter
Right
atrium
AV node
The radiofrequency ablation
catheter is directed to the
base of the pulmonary vein.
Types of Ablation
PULMONARY VEIN
ABLATION
If the pulmonary vein is the source
of the arrhythmia, such as in AF,
radiofrequency energy is used to destroy
the tissue in the area of the atrium
that connects to the pulmonary vein.
The scar that forms blocks impulses
from firing within the pulmonary vein,
preventing arrhythmias.
Pulmonary
vein
SA node
Radio-
frequency
catheter
Radiofrequency energy is used to destroy
the tissue where the atrium connects to
the pulmonary vein.