Hall-Garcia Cardiology
6624 Fannin, #2480
Houston, Texas 77030-2312
P: (713) 529-5530
F: (713) 791-1786
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Cardiac Catheterization

Cardiac catheterization involves the insertion of a long, thin tube into a blood vessel in your groin or arm. The tube will be gently directed to the heart and to the origin of the coronary arteries, as well as into the left ventricle, the heart's main pumping chamber. Dye is then injected into the coronary artery while x-ray pictures are taken. Pictures can also be taken of the left ventricle. Pressures on the left side of the heart are simultaneously measured and recorded. A cardiac catheterization permits confirmation for the presence or absence of significant blockages in the coronary arteries, can show evidence for previous, recent or ongoing heart attack, can evaluate valve function and overall heart muscle performance. These are important information for the electrophysiologist in determining probable causes for arrhythmias as well as help in tailoring the best treatment to suit an individual patient's needs. In many instances the arrhythmia is caused by a blockage; this can be treated at the same time with angioplasty

For more information, please click on the highlighted tab: cardiac catheterization.

Implantable Loop Recorder (ILR, Reveal, Reveal Plus)

An implantable loop recorder is a small device about the size of an average-sized man's thumb that is placed under the skin to diagnose causes of syncope (or passing out) or recurrent palpitations (heart pounding) that have remained elusive or could not be diagnosed after monitoring with a Holter and external loop recorder and/or even after an EP test.

Example of an ILR.

The way this device works is that it constantly monitors the heart rhythm and if one experiences any symptoms or passes out, the device can be activated to record the heart rhythm at the time of activation as well as several minutes before and after activation. That way, a detailed view of the heart's rhythm is available for analysis. Activation can be done using an external activator device or it can also be done automatically.

Schematic of ILR strategy.

Preparation for the Procedure

  • Nothing to eat or drink overnight or at least 6 hours before the procedure.
  • Remember to ask your physician for instructions about taking your scheduled medications especially if you are diabetic (on insulin or pills) and/or are taking pills that can make you prone to bleeding (i.e. Coumadin or warfarin, Plavix or clopidogrel).
  • An intravenous (IV) line may be inserted prior to the procedure.
  • An antibiotic may be given through the IV line to reduce the risk of infection.

Procedure. The procedure is a same day procedure and is performed in the cardiac catheterization laboratory or operating suite. Before anything is done, an area of your chest is selected that yields the best signal from your heart; this is usually on the left mid-upper chest. The selected area is then shaved (if applicable), cleaned with antiseptic and covered with a sterile drape. This is then numbed with a local anesthetic so that a small incision approximately 2 cm. can be made to insert the device. This incision will be closed with a few stitches or staples. No x-rays will be used during the procedure. You will be sedated according what your physician deems is necessary.

After the Procedure

  • You will be instructed on how to operate the device.
  • You may be given a short course of antibiotics.
  • You most likely will be sent home on the same day.
  • You will be instructed on wound care.You may get the wound wet after 5 days.
  • After 10-14 days, an office visit will be scheduled to check the wound and remove stitches.

Electrophysiology Study (EP Study)

An electrophysiology study or EPS is an invasive test that examines the electrical properties of the heart by the placement of special catheters inserted via the leg, arm or neck.An EP study enables your physician to search for explanations for symptoms such as palpitations, irregular heartbeats, fainting and near-fainting spells. It also helps your doctor decide on the best course of treatment (medicines, a pacemaker, defibrillator, RF ablation, or surgery; see treatment options below) which can be done in conjunction with the EP study or scheduled at a later date.

Preparation for the Procedure

  • Nothing to eat or drink overnight or at least 6 hours before the procedure.
  • Remember to ask your physician for instructions about taking your scheduled medications especially if you are diabetic (on insulin or pills) and/or are taking pills that can make you prone to bleeding (i.e. Coumadin or warfarin, Plavix or clopidogrel).
  • Your doctor may advise you to stop taking certain medications before your EP study to ensure more accurate results.
  • A chest x-ray, electrocardiogram (ECG) and blood work may be obtained. A urine pregnancy test is routinely obtained for all women of childbearing age.
  • Get a good night's sleep.
  • An intravenous (IV) line will be inserted through which fluids and medicines can be given.

Procedure. The procedure is usually a same day admission. The EP lab is similar to the laboratory used for heart catheterizations. During the EPS procedure you will be awake, but you may be given medications to help you relax. Electrodes will monitor your heart rhythm and rate. This may require that some areas be shaved in preparation.

You will be placed on a flat, cushioned table. The groin area is shaved, sterilized and numbed so a sheath can be inserted. Through this sheath, temporary pacemaker catheters--about as thick as a piece of spaghetti-- are placed in strategic areas of the heart. These catheters record electrical activity inside the heart and allow the physician to artificially "pace" or stimulate your heart. An x-ray machine the shape of a large C will be placed directly over your body and maneuvered at various angles to allow your physician to watch the catheters and see that they are properly placed. You will receive only intermittent low doses of x-rays.

Illustration of EP catheters.

Appearance of EP catheters on x-ray

Examples of x-ray machines.

Your physician will then artificially create different heart rates and will watch for arrhythmias. He may also give some drugs that make your heart rate speed up in an attempt to induce or provoke arrhythmias. During the test you may experience no symptoms whatsoever, or you may feel a rapid heart rate, skipped beats, light-headedness, chest pain or discomfort. If you experience any of these problems, please let the physician know. Sometimes you may pass out briefly during the test or an abnormal rhythm may be induced and it may become necessary to give your heart a mild electric shock to restore your normal rhythm. When you wake up, do not be alarmed if you find an oxygen mask covering your mouth and nose.

If no arrhythmia is found, the catheters are removed, the test is concluded, and you will be returned to your room. If your physician is successful in reproducing your arrhythmia, he may proceed with radiofrequency ablation or placement of a pacemaker or defibrillator (for more information on treatment, please proceed to treatment options). 

If the decision is to proceed with radiofrequency ablation, your physician will then make a "map" of your arrhythmia. This electrical map tells your physician where the arrhythmia is coming from, what areas of the heart are necessary to keep the arrhythmia going and more importantly, it tells your physician where to apply radiofrequency currentto get rid of your arrhythmia! EP studies usually last from two to four hours.

Example of an electroanatomical map of the right atrium.

Example of propagation map showing an arrhythmia (click on image to activate).

After the Procedure

  • After the catheters are removed, pressure will be applied to the puncture site just long enough to stop the bleeding. No stitches are required but a sterile dressing will be applied and can be removed the next day.
  • Remain in bed with your leg straight for anywhere between 3-6 hours. Nurses will assist you when it is OK to get up.
  • Keep your head on the pillow.
  • Inform the nurse if you have any warmth, pain or swelling where the catheters were removed.
  • If you need to cough, sneeze or strain, hold the dressing down firmly before doing so.
  • You will be permitted to eat and drink.
  • Your vital signs and catheter insertion site will be checked frequently.
  • The exact length of your hospital stay is determined by your diagnosis and the treatment option prescribed by your physician. With a regular, uncomplicated EP study, you can usually go home later the same day. If the procedure was long and complicated, or if a pacemaker or defibrillator was implanted, this usually requires an overnight stay. 
  • When the bandages are removed from the catheter insertion site, you may notice a small bruise no larger than a quarter. You may also feel a small lump there. The bruise may become slightly larger and/or darker after you return home. Both of these are part of the body's natural healing process and should disappear completely within two weeks. If you notice a discharge, or feel feverish or become very uncomfortable, please call our office immediately.

Some patients may require no further treatment. Others may require any one of the treatment alternatives described below. Your physician will explain his/her findings and recommendations following your study. However, don't be afraid to ask questions at any time before, during or after the procedure!