Heart Center
Technology & Procedures
The MedTronics InSync Congestive Heart Failure Pump
BHMC-LR
is committed to bringing cutting edge technology to the people of
Arkansas. Our cardiac program is proud to bring you resynchronization
therapy for people who have heart failure and problems with electrical
conduction in their hearts. Heart failure affects approximately
5 million Americans and is responsible for more hospitalizations
than all forms of cancer combined.
In healthy people, the four chambers of the heart contract in synchrony
to move blood through the body. However, in many patients who have
heart failure, the electrical impulses that coordinate the contractions
of the heart's chambers may be impaired. As a result, in up to 50
percent of people who have advanced heart failure, the two lower
chambers, called ventricles, no longer contract at the same time.
When
the heart is not pumping properly, mild activity can cause shortness
of breath or difficulty breathing, even when the person is lying
down. The legs and ankles may swell as a result of increased water
retention. People often feel weak and tired and may sleep more frequently.
The
Medtronic InSync system is an implantable device and specialized
leads designed to provide resynchronization therapy. The device
sends tiny electrical impulses to both sides of the heart muscle
of the lower chambers (ventricles). Resynchronizing the contractions
of the ventricles is intended to help the heart pump blood throughout
the body more efficiently. Cardiac resynchronization therapy, also
known as biventricular pacing, is intended to complement, not replace,
heart failure drug treatment and dietary modification.
For those patients with heart failure who have electrical conduction
problems of the heart, resynchronization therapy is intended to
improve the heart's efficiency and increase blood flow to the body.
By improving blood flow, heart resynchronization therapy may reduce
heart failure symptoms, improve quality of life and increase patients'
ability to perform the tasks of daily living.
Despite
advancements in treatments, tens of thousands of heart failure patients
suffer from two heart conditions that require separate therapies
¾ cardiac resynchronization and protection against fast heart
rhythms. Medtronic InSyncâ ICD system is one device developed
to treat both.
The
InSync ICD device is an implantable device designed specifically
to provide heart failure patients indicated for ICDs with both cardiac
resynchronization therapy and defibrillation protection in a single
device. The InSync ICD system is equipped with a special battery
and sophisticated electronic circuitry designed to interpret signals
from the heart, provide the actual pacing signals for cardiac resynchronization,
collect diagnostic information, and send specialized impulses when
needed to stop heart rhythms that are dangerously fast. To monitor
the heart and provide the necessary electrical stimulation for cardiac
resynchronization and defibrillation, three thin insulated wires
(called leads) connect the InSync ICD device to the heart.
The
cardiac resynchronization therapy improves the pumping efficiency
of the heart, while the ICD function is often referred to as "an
emergency room in the chest," protecting patients from potentially
lethal heart rhythms using defibrillation therapies. Patients who
receive cardiac resynchronization therapy often have more energy,
a greater ability to exercise and perform daily activities, and
a reduced number of hospitalizations from heart failure.
Resynchronizing
– and Protecting – a Failing Heart: The Medtronic InSync®
ICD
The
Medtronic InSync® ICD device, implanted in the upper chest,
is designed to resynchronize the pumping action of the heart's lower
chambers as it protects the heart against dangerously rapid arrhythmias.
In heart resynchronization therapy for heart failure, the physician
programs the InSync ICD device to deliver electrical impulses at
the precise times needed to make each chamber contribute to better
pumping action. Other functions in the same device are programmed
to monitor the electrical conduction system of the heart and to
deliver corrective impulses when needed. Two leads – tiny insulated
wires – carry impulses from the device through the vascular
system to the inner walls of the right side of the heart. A third
lead is threaded through the coronary sinus (middle of the heart)
into a vein on the exterior wall of the left ventricle.
Of
the 5 million patients in the United States diagnosed with heart
failure, approximately 750,000 may be candidates for cardiac resynchronization
therapy (CRT) available with the InSync system. Of those, an estimated
100,000 have a ventricular arrhythmia indication and could be candidates
for the InSync ICD system, which is designed to additionally provide
defibrillation protection – thus eliminating the need for multiple
implants.
The
InSync approved by the U.S. Food and Drug Administration in August
2001 provides resynchronization therapy for patients who do not
require ICD therapies. The InSync ICD device provides both resynchronization
therapy and defibrillation protection for those patients who are
at high risk for potentially lethal ventricular arrhythmias.
A specially
trained cardiologist (an electrophysiologist) or cardiovascular
surgeon implants the InSync and InSync ICD systems. The devices
are implanted under the skin in the chest area, and three very thin
insulated wires (leads), with tiny electrodes on their distal ends,
are maneuvered through a vein from the device to the heart: One
lead is placed to touch the interior wall of the right atrium, another
to touch the interior wall of the right ventricle and the third
lead is threaded through the coronary sinus and placed to touch
the outer wall of the left ventricle.
The
implantation procedure is typically done with local anesthesia,
so the patient remains conscious. However, the procedure takes longer
than a typical pacemaker implant because of the need to implant
the third lead to pace the left ventricle. Patients usually stay
in the hospital overnight.