Download Surgical Treatment for Congestive Heart Failure

Surgical Treatment for
Congestive Heart Failure
LaDale Simpson
March 1, 2007
Statistics
• Congestive Heart Failure is a common medical problem affecting over 5
million Americans annually
• 1.5-2.0% of the U.S. population at any given time is inflicted with this disease
• Over 500,000 cases are newly diagnosed annually
• Leading cause of hospitalization (80%) in patients over 65 years of age
• The impact of heart failure on society is massive, as approximately $40 billion
annually is spent on inpatient and outpatient visits.
• An additional $500 million is estimated to be spent on medications each and
every year
What is CHF?
• Congestive heart failure arises when a person’s heart is unable to keep up with
its required workload.
• The pumps in an affected heart are weakened, thus causing the blood to
move throughout the circulatory system at a reduced speed.
• As a result, the heart is unable to pump much-needed oxygen and nutrients to
meet the body’s demand.
What is CHF?
• The chambers in the heart thus respond by stretching to hold more blood or
by hardening and becoming thick.
• This allows the body, for a short time, to compensate for the inadequacy of
the valves, but with time the muscle walls of the heart begin to weaken as well.
• In response, the kidneys often cause the body to retain fluid, particularly
water and sodium.
• This fluid can accumulate in the arms, legs, ankles, feet or lungs, causing
congestion throughout the body.
Risk Factors
• CHF is closely associated with many major risk factors including:
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Age
Smoking
History of alcohol abuse
Metabolic syndrome
Coronary artery disease
Hypertension
Valve disease
Diabetes mellitus
Obesity
Family history of heart failure
Types of CHF
• There are 2 main types of congestive heart failure: systolic dysfunction and
diastolic dysfunction.
• Systolic dysfunction occurs when the heart is unable to empty completely
with contraction, and therefore, inadequate amount of blood is sent out into
circulation.
• Testing for systolic dysfunction is done by measuring the ejection fraction.
• A normal ejection fraction is more than 55% of the blood volume.
• An ejection fraction ≤45% indicates systolic dysfunction.
• If your ejection fraction is normal then you assume the patient has a diastolic
dysfunction.
• This occurs when the heart contracts normally, but the ventricles do not relax
properly or are too stiff to fill completely.
Stages of CHF
• In 2001, the American Heart Association developed four stages (A-D) to
classify patients suffering from congestive heart failure, which were later
revised in 2005.
• Stage A: patients that are high risk to develop CHF but have no structural
damage or symptoms pertaining to the disease.
• Stage B: patients have some sort of structural damage to the heart, usually
detected with an echocardiogram test, but are yet to experience any symptoms
• Stage C: patients are those patients who have structural damage and also have
prior or current symptoms.
• Stage D: patients are patients who, even after receiving optimum medical care,
still have advanced symptoms. These are the patients that become candidates
for surgical procedures and/or mechanical assist devices, and often require
hospitalization or hospice care.
Surgery
• Surgery is not often used to treat patients with congestive heart failure.
• However, it can be a logical method of treatment in cases in which traditional
treatments are not working for whatever reason.
• These such surgeries present a great risk, thus physicians seek to identify
patients who have the greatest to gain from surgical intervention.
Heart Transplant
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Perhaps the only current treatment that
is capable of fully reversing the
congestive heart failure is receiving a
complete heart transplant, in which
surgeons replace the damaged heart
with a healthy one taken from a donor
who has been pronounced brain dead.
Surgeons remove the healthy heart
from the donor, keep it in a cooled
environment, and then it is transported
to the medical facility in which the
recipient is waiting for it.
The back walls of the atrias in the
recipient’s body are kept intact and the
atrias of the new heart are sewn
together at this point.
Blood vessels are then reconnected.
Timing is everything, as a healthy heart
can only exist out of the human body
for 4-6 hours.
Heart Transplant
• There is a much greater number of patients who suffer from congestive heart
failure and could potentially benefit from a heart transplant than there are
healthy donated hearts.
• Due to this fact, there is a strictly screened heart transplant list.
• Possible patients are evaluated on many different levels including age, medical
history, diagnostic test results, social history and psychosocial evaluation.
• Only patients who are believed to be able to survive the surgery and who will
comply with years of disciplined living afterwards are considered for the list.
• This list is prioritized according to the severity of illness, blood type and
geographic location.
• Once a patient is added to the donor list it is a long, stressful wait before he
or she might receive a healthy heart
Left Ventricular Assist Device
• The left ventricular assist device
(LVAD) serves as a “bridge to
transplantation” for patients in
whom medical therapy has not
worked and are waiting for a heart
transplant, or as a destination
therapy for patients who are nontransplant candidates due to age or
comorbidity
• This device supplements the
function of the left ventricle when
its pumping ability is damaged
• It is a portable, battery-powered
pump which is implanted in the
abdominal wall and is connected to
the heart in two places.
Left Ventricular Assist Device
• The pump pulls blood from the
left ventricle and then sends it to
the aorta, from which blood is
pumped out into circulation.
• Thus, this allows blood to keep
pumping through the heart at the
rate in which the body demands.
• An additional tube extends from
the LVAD to the outside of the
body and transports wires to a
controller which the patient
typically wears on a belt.
• The batteries are normally located
on a shoulder holster which also
connects to the controller.
Left Ventricular Assist Device
• Left ventricular assist devices are typically worn for weeks to months and
serve to buy time for the patient, regardless of whether he or she is a
candidate for a heart transplant.
• It allows the patient to return home and attempt to live a semi-normal life.
Coronary Artery Bypass Graft
• The most common type of surgical
procedure performed on a patient
suffering from congestive heart
failure is a coronary artery bypass
graft (CABG).
• During a bypass operation an
artery or vein is removed from
another healthy part of the
patient’s body, such as a leg, arm or
the chest wall.
• This removed blood vessel is then
surgically attached in a way that it
allows blood to bypass, or go
around, the affected portion of the
pre-existing blood vessel and thus
becomes a graft.
Coronary Artery Bypass Graft
• A coronary artery bypass traditionally calls for an open-heart surgery and the
use of a heart-lung bypass machine to circulate the blood while the patient is
having the surgery.
• Minimally invasive procedures have been developed in which multiple smaller
openings, or “keyholes,” are made in the chest.
• This procedure has many benefits:
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less scarring
shorter hospital stay
faster recovery
less bleeding during surgery
reduced chance of post-operative infection
less pain afterwards
Coronary Angioplasty
• Coronary angioplasty is a medical
surgery that is used to restore
blood flow through a narrowed or
blocked artery in the heart.
• A narrow, hollow catheter with a
balloon on the end is inserted into
a blood vessel in the arm or upper
thigh and is guided to the diseased
portion of the artery.
• It is then inflated, which forces any
plaque that is responsible for the
narrowing outward against the wall
of the artery, thus widening the
artery and restoring the blood flow.
• After the widening of the artery
takes place, the balloon and
catheter are removed.
Coronary Angioplasty
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Since its development in 1977 the stent
has decreased the risk by 50% of an
artery closing again after an angioplasty.
Stents are tiny structures made of wire
mesh that surgeons insert to prop open
arteries that have been dangerously
narrowed or clogged with fatty plaque.
The first stents were made with a bare
metal but now most of them are
coated with medications that aid the
recovery of the artery from the surgery.
The usage of plaque removers and
lasers have also provided beneficial
tools to aid angioplasty.
Plaque removers are used to cut away
the plaque while lasers dissolve plaque
in the arteries while performing the
angioplasty.
Electrical Signaling
• The pumping of a normal, healthy heart is achieved from impulses sent
through the organ by its very own electrical system.
• It is vital that this rhythm of squeezing blood through the heart is done at a
steady rate, for if not, the heart will ultimately lose its functioning capability.
• Some patients have an abnormality of this electrical system in the heart:
– bradycardia
– tachycardia
• The majority of congestive heart failure patients suffer from an additional
abnormality of this rhythm, in which the two ventricles do not contract
simultaneously.
• Treatment of all three of these conditions may be done surgically, with
implantation of some sort of electrical device.
Electrical Signaling
• A pacemaker is a small device that aids a heart’s SA node.
• This device detects heart rate of a patient.
• When the heart rate drops below a set rate (which is determined by a
physician) it send an electrical impulse that passes through the heart’s muscle,
just as the SA node does.
• Thus, the heart contracts and pumps as it is intended to, correcting the
bradycardia.
Electrical Signaling
• A pacemaker is implanted just
below the skin of the chest of the
patient in a minor procedure.
• It is comprised of a pulse
generator and the leads.
• The generator houses the battery
and a tiny computer that monitors
the patient’s heart rate and
determines when to send an
electrical impulse.
• The leads are wires that are
threaded through the veins into the
heart and implant in the heart
muscle.
• They are the connection that sends
impulses from the generator as
needed.
Implantable Cardiovascular
Defibrillator
• Tachycardia is repaired by a device
known as an implantable
cardiovascular defibrillator, or ICD.
• It, also, is a pace-making device
that is placed just below the skin of
the patient’s heart which monitors
its rate and rhythm.
• When the ICD detects an
abnormally fast heart rate, it
delivers a series of small electrical
impulses in a similar manner as the
typical pacemaker.
• This impulse causes the heart to
beat in a normal, slower rhythm
again.
Cardiac Resynchronization Therapy
• The hearts of some congestive
heart failure patients have a delay
in electrical conduction through
the left bundle branch, which
transmits the heart’s electrical
impulses to the left ventricle from
the left atrium.
• This is termed a left bundle branch
block, or LBBB, and causes a delay
in left ventricular contraction
compared to that of right
ventricular contraction.
• This results in an asynchronous
contraction, which further weakens
the heart’s pumping efficiency.
Cardiac Resynchronization Therapy
• The recommended treatment for
LBBB is cardiac resynchronization
therapy, or CRT, which requires a
sort of biventricular pacemaker.
• Tiny electrical impulses are sent via
leads to the right atrium and then
to the two ventricles concurrently,
ensure their simultaneous
contractions.
• This method of surgical treatment
eliminates the delay caused by the
LBBB and is typically
recommended for patients
suffering from stage D congestive
heart failure.
Heart Valve Repair
• Heart valves are flaps of tissues that ensure that blood traveling through
different chambers of the heart and into circulation moves in the proper
direction and does not flow back from where it came from.
• Heart valve disease can be caused by infection, congenital heart disease or
aging, and may cause the valves to either not close properly, resulting in a
leaky valve, or not open completely, resulting in a decrease in blood flow.
• Both of these circumstances make the heart work harder than normal and
may worsen the extent of congestive heart failure the patient is suffering from.
• Depending on the severity of the condition, defective valves may need to be
either repaired or completely replaced.
Heart Valve Repair
• Complete valve replacement
involves the removal of a damaged
valve and insertion of a new valve
in its place.
• This new valve may be an artificial
valve made of metal or plastic, or
may be a donated valve from a
human donor.
• During this surgery a patient is
connected to a heart-lung machine.
• Following the surgery the patient
must be placed on a regimen of
anticoagulation therapy to prevent
blood clots in the area of the new
valve.
Heart Valve Repair
• New developments over the years have developed a minimally invasive repair
option for patients.
• With this most advanced technology a damaged valve can be repaired with an
incision between the ribs of approximately 2.5 cm in diameter, opposed to
the traditional open-heart surgery.
• This surgery, called a mini-thoracotomy, lessens a patient’s post-operative
scarring, recovery time and discomfort.
• The “Bow Tie” procedure uses a single stitch to join the valve leaflets when
they do not properly come together, and can be done in a minimally invasive
manner.
Heart Valve Repair
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Mitral regurgitation is a condition in
which the mitral valve – the valve
between the left atrium and the left
ventricle – allows backflow of the
blood from the ventricle into the
atrium after is has been pumped
through the valve.
This condition is existent in virtually
all patients with congestive heart
failure and is due to remodeling of
the left ventricle.
Mitral valve repair typically involves
restructuring the leaflets of the
valves and providing a sort of
support with a ring.
Preservation of the mitral valve
contributes to decreasing wall stress,
improving systolic and diastolic
function and enhances proper
geometry of the left ventricle.
Left Ventricular Reconstruction
• In a failing heart, the normal elliptical shape of the left ventricle is lost.
• The ventricle dilates and remodels in response to its inability to pump
efficiently, creating a spherical shape.
• Ironically, this remodeled shape eventually turns from being compensatory
and beneficial to a contributing cause of heart failure and mitral regurgitation.
• As the ventricle walls pull apart the mitral valve is no longer able to close
completely, thus regurgitation takes place.
• In this instance it proves beneficial to reconstruct the shape of the left
ventricle.
Left Ventricular Reconstruction
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The leading procedure by today’s standards
is the Dor procedure.
With this technique a mannequin device is
used to remove any scar tissue in the left
ventricle that may be present from previous
damage.
The surgeon enters the left ventricle through
the anteroapical scar.
Once the dead tissue determined, a Dacron
patch is sutured for the ventricle to close
over.
This prevents destruction of the left
ventricle.
Another leading surgery involves a polyester
mesh cardiac support device, the Acorn
CorCap.
The device wraps around the ventricle from
posterior to anterior, using sutures, and
girdles the heart, helping to retain its
elliptical shape.
It provides more end diastolic support and
reduces wall stress.
Post-Operative Recovery
• Patients who receive a surgical measure of treatment for congestive heart
failure often face a long road of recovery following the procedure.
• These patients are given a strict set of guidelines in which they are
responsible to follow for a period of weeks to months.
• The patient should take proper care of any incisions in which he or she
obtained with the procedure.
• They should be kept clean and dry, using only a mild soap and water to clean
them.
• If there are any signs of an infection, such as drainage, opening of the
incision line, redness or warmth around the area or an increase in body
temperature then a physician should be contacted immediately.
• If the patient underwent an open-heart procedure a physician should also be
contacted if he or she feel as if the sternum has moved or feels like it has
popped
• Pain relievers are typically given to make a patient feel more comfortable, but
the patient and/or his or her family should take care to make sure that no
more than the prescribed dosage is taken.
Conclusion
• Congestive heart failure has become an emerging epidemic the in the world
today, affecting over 5 million Americans in our country alone.
• Pharmacologic treatments are considered a first option for its treatment, but a
wave of new, surgical courses of treatments has began to develop.
• It is essential for critical appraisal of these surgical therapies so that they can
be offered to the growing population suffering from heart failure.
• Although a complete heart transplant is considered to be the gold standard of
treatment for a failing heart, there are far too few donor hearts to supply an
ever-growing population who potentially could benefit from them.
• This is why it is crucial to seek other approaches to correcting this problem.
Conclusion
• All of the methods described have
proven beneficial to expanding the
duration and increasing the quality
of the lives of congestive heart
failure patients, and have allowed
the majority of them who have
received the operations to maintain
a normal lifestyle.
• Although these surgeries are
currently considered to be a bridge
to transplantation, prolonging life
until a donor heart may come
available in the future it is a great
possibility that they will be
considered an equally life-saving
method.
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