An EP Study is the monitoring and recording of the electrical activity
the heart. This test is used to help find out the cause of your rhythm
disturbance and the best treatment option for you. During the test, the
doctor may safely reproduce your arrhythmia to diagnose your specific
type and locate the site of origin of the abnormal heart rhythm.
In most cases, EP testing and the Radio-frequency therapy performed during
the same setting can cure the arrhythmia. The procedure takes approximately
two to four hours to complete.
Each year more than 300,000 people die suddenly in the United States. This
is termed sudden cardiac death or sudden cardiac arrest. The most common
arrhythmia leading to sudden cardiac arrest (SCA) is ventricular fibrillation
(VF), an arrhythmia of the heart in which the heart quivers rather than
beats effectively. When this happens, the heart no longer supports circulation,
the patient loses consciousness and, if normal rhythm is not restored
quickly, the patient will not survive. VF is often preceded by another
abnormal, fast rhythm called ventricular tachycardia (VT). In VT the heart
usually maintains some pumping function although in the majority of patients
it is not enough to support circulation either. VT usually degenerates
into VF if normal rhythm is not restored quickly.
There are several types and manufacturers of ICD. Generally, they consist
of an oval shaped device generator and two or three leads. The generator
contains the small computer that monitors the rhythm, detects arrhythmia
and determines if treatment is needed. It also houses the battery and
the device that delivers the shock through the leads. The leads are essentially
wires that are attached to the ICD on one end, with the other ends positioned
in different locations within the heart chambers. Implanting an ICD is
generally considered a minor surgical procedure and is usually done with
sedation and local anesthetic.
Following the implant, the doctor will monitor you and your device regularly
to maintain proper functioning.
The Stead Heart and Vascular Center Pacemaker Clinic evaluates and manages
the care of patients prior to and following the implantation of cardiac
pacemakers and automatic internal cardioverter defibrillator systems.
The frequency of a patient's evaluation is determined by the patient's
needs, the age and type of pacing device, and the cardiologists recommendations.
A typical schedule will include both clinical visits and telephone monitoring.
Telephone monitoring utilizes specifically designed transmitter units
that the staff to analyze how well the pacemaker is working while the
patient is at home.
During a visit to the Pacemaker Clinic patients are seen by nursing professionals
who check and record pulse and blood pressure, review current medications,
inquire about symptoms such as sudden dizzy spells, lightheadedness, and
fatigue and check the device insertion site.
Patients will receive an electrocardiogram and, using an electronic device,
the nurses will interrogate or "read" information from the device
to check for function and battery life and make any adjustments needed.
By identifying problems in advance, the medical staff at the Legacy Pacemaker
Clinic is able to maximize pacemaker functioning. For example, patients
who receive timely evaluations may find that they can prolong pacemaker
life, anticipate and plan for their replacements when appropriate, and
even identify changes in heart rhythms that necessitate pacemaker reprogramming.
A pacemaker is a small, battery-powered device that sends out weak electrical
impulses that cause the heart muscle to contract. A pacemaker can be used
to replace the function of the natural pacemaker of the heart when the
heart is beating too slowly. It consists of wires (leads), which transmit
electricity to the heart, and the pulse generator and battery, which generate
the electrical impulses. The battery in a permanent pacemaker usually
lasts 5 to 15 years. Your doctor will monitor your pacemaker regularly
to decide when the battery should be changed.
Pacemakers are surgically placed into the chest (a permanent pacemaker)
through a small incision. There are several types of implantable pacemakers.
- A fixed-rate pacemaker gives off electrical impulses at a steady, regular
rate, regardless of your level of activity. A rate-responsive pacemaker
changes the rate of electrical impulses as your activity level changes.
- A single-chamber pacemaker controls only the lower chamber of the heart
- A dual-chamber pacemaker controls both the top (atrium) and bottom (ventricle)
chambers of the heart.
- Many times the pacemaker is set to work only when the heart rate falls
below a certain predetermined rate (demand mode).
The surgery needed to implant a permanent pacemaker is considered a minor
surgical procedure. It can usually be done using local anesthesia, which
means part of your body is numbed, but you stay awake. A small incision
is made in the chest wall. The pacemaker leads are usually threaded through
the incision into a large blood vessel in the upper chest and into the
heart. Using the same incision, a small pocket is created under the skin
to hold the pulse generator. The leads are then hooked up to the pulse
generator. The entire procedure usually takes about 1 hour.
A non-surgical procedure called radiofrequency catheter ablation is utilized
to cure many heart rhythm disturbances. In this procedure thin, flexible
wires are inserted into a vein in the groin and threaded up through the
vein and into the heart. Through an electrode at the tip of the wires,
radio waves can be delivered to selectively destroy heart tissue responsible
for the abnormal heart rhythm.
Radiofrequency catheter ablation can also be used when persistent chronic
atrial fibrillation does not respond to treatment with medication and
symptoms continue to be bothersome. It is most often used in people who
have difficult-to-control heart rates. The normal conduction area is ablated
which then requires a pacemaker be implanted to maintain normal heart
rhythm after the ablation. Ablation followed by pacemaker implantation
reduces cardiac symptoms and improves exercise tolerance, quality of life,
and the amount of blood pumped with each heartbeat.
Radio-frequency ablation has also been utilized to cure certain patients
with atrial fibrillation. These patients, however, are usually younger
who have had the arrhythmia for a short time.
For more information on Pomona Valley Hospital Medical Center's Stead
Heart & Vascular Center, please call 909.865.9858.