Assessments for the Heart’s Electrical System and Activity
A procedure that destroys the specific area of the heart that begins the abnormally fast signals. Endocardial mapping is first done, which locates the area of the heart that is causing the abnormal signals.
Once the abnormality is found, either radiofrequency waves or small incisions are used to destroy or stop that heart tissue from sending any signals. Ablation therapy can be done by using a catheter or during open heart surgery.
With the catheter approach, a small catheter is inserted into a vein and guided into the heart. When the specific heart tissue is located, the tissue is destroyed—either by heat (resulting from short bursts of radiofrequency or laser energy) or by small cuts that create scars.
This procedure is done in the outpatient setting and is painless, requiring local anesthesia. Ablation therapy cures arrhythmias most of the time. This is the only treatment for patients with ventricular tachycardia or some arrhythmias.
Biventricular Pacing (Also Known as Resynchronization Therapy)
A biventricular pacemaker is designed to treat the delay in heart ventricle contractions. It keeps the right and left ventricles pumping together by sending small electrical impulses through the leads.
In a normal heart, both the upper (atria) and lower chamber (ventricle) pump at the same time. When a person has heart failure, however, both chambers do not pump together.
When the heart's contractions become out of sync, the left ventricle is not able to pump enough blood to the body. This eventually leads to an increase in heart failure symptoms, such as shortness of breath, dry cough, swelling in the ankles or legs, weight gain, increased urination, fatigue, or rapid or irregular heartbeat.
A biventricular pacemaker is usually recommended for heart failure patients who:
Electrophysiology studies are done by Dr. Trevor Greene in an outpatient hospital setting. EP studies are done to test the heart’s electrical system. The electrical system is what generates the heartbeat.
During this invasive procedure, an X-ray, referred to as fluoroscopy, is done by inserting a catheter through a vein in the groin (or sometimes the arm). Electrical signals are sent through this catheter to the heart tissue to evaluate the electrical conduction system contained within the heart muscle tissue.
A few different ways to test the abnormalities of the conduction system are:
Mapping: this method locates the point of origin of the dysrhythmia (an abnormal rhythm). If an abnormality is found, an ablation (removal of the spot by freezing or radiofrequency) may be done to correct the dysrhythmia.
Stimulation of the dysrhythmia may be done by an electrical signal, in which case medication may be given to treat the dysrhythmia. Another attempt is made to stimulate the dysrhythmia in order to evaluate the effectiveness of the medication once it is given.
How do rhythm problems affect the heart? Problems may occur when the heart beats too fast, too slow, or with an irregular rhythm. The effects are often the same.
One of the most common dysrhythmias is premature ventricular beats, or PVCs. PVCs are when the ventricle is contracting and pumping out blood before the atrium has completely pumped its blood volume into the ventricle. PVCs are harmless.
Almost everyone has had them at one time or another. This can cause weakness, palpitations, or low blood pressure.
Some dysrhythmias occur only intermittently, and cannot be seen on a routine EKG or a Holter monitor. If your physician suspects a problem with the heart's conduction system and cannot diagnose the problem with either of the tests, then he/she may decide that an EP study would be appropriate.
These devices record your heart rhythm. Holter monitors record for 24 hours, while event monitors can be worn for longer periods (2 weeks to a month), and each event is recorded at the push of a button.
These types of devices are worn to detect the heart rhythm during day and night activities and at rest. You are given a diary to log symptoms or activities that you are doing at the time of the event, which will help your physician treat your condition.
These monitors are hooked up to the patient in the office or hospital setting by placing sticky patches over the chest area with electrodes that are connected to the device, which can be worn on your side, that records your rhythms.
The events that are recorded can be transmitted over the phone to your physician’s office in order for him/her to monitor your events.
ICD Placement (Implantable Cardioverter Defibrillator)
While pacemakers are used to treat a slow heartbeat, ICDs are used to treat rapid heart rhythms. Some common rapid heart rhythms are ventricular tachycardia (VT), ventricular fibrillation (VF), and atrial fibrillation (A Fib).
A defibrillator is one of three parts of a defibrillation system (defibrillator, leads, and a programmer). Two of these parts are placed inside the body. These two parts work together to recognize a rapid heart rhythm, deliver one or more therapies until a normal rhythm is reached, and store data about each episode.
When the defibrillator detects that the heart rhythm is too fast, it sends an electric impulse to your heart, which can return your heart to a normal rhythm. Defibrillators deliver three types of therapies: pacing, cardioversion, and defibrillation:
Pacing: When your heart beats too fast, your device is programmed to send pacing pulses to moderate your rhythm to a normal rate. You usually will not feel these pulses.
Cardioversion: Cardioversion shocks are stronger electric pulses that feel more like a hit to the chest or a “thump.” You may feel a little lightheaded or dizzy when this occurs.
Defibrillation: This is a heavy shock when your heartbeat becomes unstable or irregular. When this happens, it may cause you to faint. Many people that have had this occur say it feels like a “kick in the chest.” This is usually over quickly.
Implantable Loop Recorder (ILR)
Sometimes events do not occur as often or are harder to catch. In this situation, your physician may suggest an ILR. This device is about the size of your pinkie. This procedure is done in an outpatient hospital setting and is implanted under the skin. The incision made is usually about one inch.
Anytime an event occurs, it is recorded and read with radio waves by a programmer machine. This device can be worn for up to a year, as the battery life expectancy is about 14 months. The same procedure would be repeated for the removal of the device. This device does not send out electricity; it is simply a recording device.
Why do I need one? A pacemaker is usually recommended for patients with an abnormally slow heartbeat (also known as bradycardia). When your heartbeat is less than 60 beats per minute, it is usually considered irregular, and your body may experience fainting, dizziness, shortness of breath, or fatigue.
A pacemaker can be inserted and programmed to keep the heart beating at a normal rate so that you may continue your everyday activities without experiencing these symptoms.
A pacemaker consists of two parts that are placed inside the body: the pacemaker itself, and a pacing lead. A pacemaker is a small device that is placed under the skin, usually as an outpatient procedure at the hospital, and the patient can go home the same day.
A pacing lead is a wire that carries a tiny electrical pulse to the heart. The pacing lead is guided through a vein into the heart, and a “pocket” is created under the skin where the pacemaker is placed and the lead is connected.
The incision site may be red and swollen for a few days after surgery, but this is normal. There will be a slight bulge at the pacemaker site after insertion, but after the site has healed, the swelling and redness should disappear. If it does not, you should contact your physician immediately.
You will be given a pacemaker ID card that will identify you as a pacemaker wearer. This card has important information about the type of pacemaker you have. It is important that you keep this with you at all times!
Pacemaker follow-ups are very important! This is how your physician monitors how your pacemaker is functioning. This can be done in your doctor’s office and also by telephone.
The frequency of monitoring changes during the lifetime of your pacemaker with more frequent checks as your pacemaker nears the expected time of replacement. The average life of a pacemaker is six years.