Patient Education

 

Syncope

Syncope is a transient loss of consciousness. The diagnosis of the cause of syncope can be complicated and require the assessment by a specialist in heart rhythm abnormalities. Although many causes of syncope require no treatment, abnormal slow heart rate (i.e. bradycardia) or abnormal fast heart rate (i.e. tachycardia) is common causes.   Non-invasive tests such as tilt table studies, Holter monitors, event/loop recorders are often necessary to diagnose the cause of syncope. Occasionally, a special invasive test called an electrophysiology study (EP study) is necessary to diagnose syncope. An EP study involves placing specialized catheters in the heart through the large veins in the groin. These specialized catheters allow for electrical stimulation of the heart as well as recording the electrical properties of the heart. A series of pacing exercises are performed that test the heart’s electrical system.  Bradycardia can be treated with implantation of a permanent pacemaker. A permanent pacemaker is a specialized medical device implanted underneath the skin in the shoulder region. One or more electrical wires (i.e. leads) is placed through a large vein in the shoulder region into the heart and then connected to a small pacemaker generator.   Tachycardia can be treated with either medications, cardiac rhythm devices, or specialized catheter-based procedures called ablation which may cure some abnormal fast heart rhythms.

 

Supraventricular Tachycardia

Supraventricular tachycardia is an abnormal regular rapid heart rhythm that originates in the upper chambers of heart. Patients with supraventricular tachycardia feel their heart racing, lightheadedness, sometimes shortness of breath or chest pain, and occasionally they may lose consciousness.  It is often caused by an abnormal circuit in the heart (i.e. reentry) or occasionally by an abnormal tissue in the upper chamber firing rapidly. Although medications can sometimes be used to control these rhythms, specialized catheter based procedures called ablations can often cure supraventricular tachycardia. During ablations, special catheters are placed in the heart through large veins in the groin which carefully map the abnormal circuits or areas of the upper chamber responsible for the arrhythmia. Utilizing radio-frequency energy to heat up small areas of heart tissue, these circuits or abnormal areas in the upper heart chambers can be eliminated. These procedures are usually safe and very effective in curing supraventricular tachycardia.

 

Atrial Fibrillation

Atrial fibrillation is the most common arrhythmia, affecting 2.2 million Americans. Normally, the heart’s electrical activity is generated in the upper chambers of the heart (atria). After the atria contract this electrical activity conducts into the lower heart chambers (ventricles) which do most of the work of pumping blood.   In atrial fibrillation, there is very rapid disorganized beating of the atria which drives the ventricles to beat rapidly and irregularly. Because the atria are not contracting effectively, blood clots can form in these chambers, eventually leave the heart, and lodge in the blood vessels of the brain resulting in stroke. In fact, about 15% of all strokes are in patients with atrial fibrillation. Patients with atrial fibrillation may feel heart fluttering or racing, fatigue, shortness of breath, or chest pain. There are many ways to treat patients with atrial fibrillation and the approach to treatment must be individualized to the patient. Medications which slow the heart rate and/or restore normal rhythm are usually the first line of therapy. Sometimes an electric shock performed during deep sedation to restore normal rhythm is necessary. Many patients require blood thinners (e.g. warfarin) to reduce the risk of stroke.  Recently, a catheter based procedure has been developed to potentially “cure” atrial fibrillation. In most patients, rapid electrical activity around the pulmonary veins in the left atria (the left upper chamber of the heart) trigger atrial fibrillation.  Radiofrequency ablation around these veins (i.e. pulmonary vein isolation) can eliminate atrial fibrillation (figure 1).  This procedure is reserved for patients with symptomatic atrial fibrillation for which medications don’t work or produce too many side effects. 

 

Ventricular Tachycardia/Fibrillation

Ventricular tachycardia is an abnormal rapid heart rhythm which originates from the from the lower heart chambers (i.e. ventricles). In patients with hearts that appear structurally normal, this arrhythmia may cause rapid heart racing, chest pain, lightheadedness, or loss of consciousness. Medications may control symptoms and reduce the frequency of these arrhythmias. However, specialized catheter-based procedures called ablations can usually cure these arrhythmias.  In patients with previous heart attacks or abnormal heart muscle (i.e. cardiomyopathy), ventricular tachycardia/fibrillation can be a life-threatening heart rhythm. Sudden cardiac death or cardiac arrest is most often caused by rapid and/or chaotic heart rhythms from the lower heart chambers (i.e. ventricular tachycardia and ventricular fibrillation).  Survival from this deadly condition depends on the delivery of an electric shock to the heart to restore normal rhythm within seconds. Unfortunately, less 5% of patients who experience this condition survive to make it to the hospital. Patients who do survive this condition are candidates for implantation of a implantable cardioverter/defibrillator (i.e. ICD).  An ICD is sophisticated medical device that is implanted in the skin much like a pacemaker with specialized wires (i.e. leads) that connect to the heart. These wires are placed through a large vein that runs under the collar bone (figure 2).  The device watches every single heart beat and is capable of delivering a small electric shock during a life threatening arrhythmia in order to restore normal rhythm. Because patients with weak heart muscle (from heart attacks or otherwise) are at very high risk for sudden cardiac death, implantation of an ICD is recommended for patients as well.  Rarely, patients with diseased hearts have frequent episodes of ventricular tachycardia/fibrillation which do not respond to medications and may result in frequent ICD shocks.  In this select group of patients, special catheter-based radiofrequency ablation procedures  have been developed which can eliminate these frequent arrhythmias.

 

The heart is a pump- a pump with valves, plumbing supply and electrical system. Cardiac electrophysiology relates to the field of abnormalities of the electrical system and rhythm of the heart. Abnormal rhythms may present as skipped beats, recurrent palpitations or as more sinister abnormalities that cause one to collapse abruptly. Other presenting manifestations include progressive fatigue, weakness, shortness of breath or a general worsening of the overall functioning of the heart. Certain cardiac rhythm abnormalities also pose risks for stroke.

 

Patients with abnormally slow heart rates can be treated with cardiac pacemakers.
Other patients, who are at risk for sudden death, either because of prior heart attacks or because of abnormal heart function may require implantation of a cardiac defibrillator.
Some patients with worsening heart failure have “wiring” blockage and may benefit from special pacemakers and defibrillators that help synchronize the way the heart contracts and functions. Implantation of a pacemaker or defibrillators is typically performed under mild sedation in a sterile setting in specialized cardiac catheterization labs in hospital.

 

Rhythm abnormalities from the atria (the upper chambers of the heart) include supraventricular tachycardia, atrial tachycardia, atrial flutter, and atrial fibrillation. Rhythm abnormalities from the ventricles ( the bottom chambers of the heart) include skipped beats (also called PVC’s) or more sinister and lethal arrhythmias such as ventricular tachycardia. Such abnormalities can be treated with antiarrhythmic medication, or by mapping and ablation. Mapping out the arrhythmia involves a study of the electrical system of the heart, an electrophysiologic study (EP). Such studies are performed in specialized cardiac catheterization labs in hospitals. Once the focus of the arrhythmia, or the short circuit involved, is identified, it is “cauterized” (ablation) using radiofrequency (similar to microwave energy). EP studies and ablations are typically performed under mild sedation with the advancement of specialized wires into the heart from veins in the groin. They are about as painless as having an IV inserted in your arm. Procedures typically last between one and four hours. Most patients plan on spending one night in the hospital for observation.


 

Informative Links:

 

 

Patient Forms Testimonials