Clinical cardiac electrophysiology
Encyclopedia
Cardiac Electrophysiology (also referred to as clinical cardiac electrophysiology , Arrhythmia Services , or electrophysiology
), is a branch of the medical specialty of clinical cardiology
and is concerned with the study and treatment of rhythm disorders of the heart
. Cardiologists with expertise in this area are usually referred to as electrophysiologists. Electrophysiologists are trained in the mechanism, function, and performance of the electrical activities of the heart
. Electrophysiologists work closely with other cardiologists and cardiac surgeons to assist or guide therapy for heart rhythm disturbances (arrhythmias).They are trained to perform interventional and surgical procedures to treat cardiac arrhythmia.
The training required to became an electrophysiologist is long and requires 7 to 8 years after medical school (in the U.S.). Three years of Internal Medicine
residency
, three years of Clinical Cardiology
fellowship
, and one to two (in most instances) years of Clinical Cardiac Electrophysiology.
An electrophysiology study is a term used to describe a number of invasive (intracardiac) and non-invasive recording of spontaneous electrical activity as well as of cardiac responses to programmed electrical stimulation. These studies are performed to assess arrhythmias, elucidate symptoms, evaluate abnormal electrocardiograms, assess risk of developing arrhythmias in the future, and design treatment.
In addition to diagnostic testing of the electrical properties of the heart, electrophysiologists are trained in therapeutic and surgical methods to treat many of the rhythm disturbances of the heart. Therapeutic modalities employed in this field include antiarrhythmic drug therapy and surgical implantation of pacemakers
and implantable cardioverter-defibrillators.
Electrophysiology
Electrophysiology is the study of the electrical properties of biological cells and tissues. It involves measurements of voltage change or electric current on a wide variety of scales from single ion channel proteins to whole organs like the heart...
), is a branch of the medical specialty of clinical cardiology
Clinical cardiology
Clinical cardiology is an American journal about Cardiology founded in 1978. It provides a forum for the coordination of clinical research in diagnostics, cardiovascular medicine and cardiovascular surgery.-External links:* *...
and is concerned with the study and treatment of rhythm disorders of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
. Cardiologists with expertise in this area are usually referred to as electrophysiologists. Electrophysiologists are trained in the mechanism, function, and performance of the electrical activities of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
. Electrophysiologists work closely with other cardiologists and cardiac surgeons to assist or guide therapy for heart rhythm disturbances (arrhythmias).They are trained to perform interventional and surgical procedures to treat cardiac arrhythmia.
The training required to became an electrophysiologist is long and requires 7 to 8 years after medical school (in the U.S.). Three years of Internal Medicine
Internal medicine
Internal medicine is the medical specialty dealing with the prevention, diagnosis, and treatment of adult diseases. Physicians specializing in internal medicine are called internists. They are especially skilled in the management of patients who have undifferentiated or multi-system disease processes...
residency
Residency (medicine)
Residency is a stage of graduate medical training. A resident physician or resident is a person who has received a medical degree , Podiatric degree , Dental Degree and who practices...
, three years of Clinical Cardiology
Cardiology
Cardiology is a medical specialty dealing with disorders of the heart . The field includes diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology...
fellowship
Fellowship (medicine)
A fellowship is the period of medical training in the United States and Canada that a physician may undertake after completing a specialty training program . During this time , the physician is known as a fellow...
, and one to two (in most instances) years of Clinical Cardiac Electrophysiology.
An electrophysiology study is a term used to describe a number of invasive (intracardiac) and non-invasive recording of spontaneous electrical activity as well as of cardiac responses to programmed electrical stimulation. These studies are performed to assess arrhythmias, elucidate symptoms, evaluate abnormal electrocardiograms, assess risk of developing arrhythmias in the future, and design treatment.
In addition to diagnostic testing of the electrical properties of the heart, electrophysiologists are trained in therapeutic and surgical methods to treat many of the rhythm disturbances of the heart. Therapeutic modalities employed in this field include antiarrhythmic drug therapy and surgical implantation of pacemakers
Cardiac pacemaker
right|thumb|350px|Image showing the cardiac pacemaker which is the SA nodeThe contraction of heart muscle in all animals with hearts is initiated by chemical impulses. The rate at which these impulses fire controls the heart rate...
and implantable cardioverter-defibrillators.
Diagnostic testing
- Ambulatory electrocardiographic monitoring - Holter recording and interpretation, loop recording and interpretation;
- Tilt table testing;
- T-wave alternans testing;
- Signal-averaged electrocardiogramSignal-averaged electrocardiogramSignal-averaged electrocardiography is a special electrocardiographic technique, in which multiple electric signals from the heart are averaged to remove interference and reveal small variations in the QRS complex, usually the so-called "late potentials"...
(SAECG) interpretation, also referred to as "late potentials" reading; - Electrophysiology studyElectrophysiology studyAn electrophysiology study is a minimally invasive procedure which tests the electrical conduction system of the heart to assess the electrical activity and conduction pathways of the heart. The study is indicated to investigate the cause, location of origin, and best treatment for various...
(EPS) consists in the insertion of pacing and recording electrodes either in the oesophagus (intra-oesophageal EPS) or, through blood vessels, directly into the heart chambers (intra-cardiac EPS) in order to measure electrical properties of the heart and, in the case of intra-cardiac EPS, to electrically stimulate it in the attempt to induce arrhythmias for diagnostic purposes ("programmed electrical stimulation").
Medical treatment
- Initital administration and monitoring of the effect of drugs for treatment of heart rhythm disorders. Electrophysiologists are often involved when severe or life threatening arrhythmias are being treated, or when multiple drugs must be used to treat an arrhythmia.
Catheter ablation
- Ablation therapy - Catheter based creation of lesions in the heart (with radiofrequency energy, cryotherapy (destructive freezing), or ultrasound energy) to cure or control arrhythmias (see radiofrequency ablationRadiofrequency ablationRadio frequency ablation is a medical procedure where part of the electrical conduction system of the heart, tumor or other dysfunctional tissue is ablated using the heat generated from the high frequency alternating current to treat a medical disorder...
). Ablation is usually performed during the same procedure as the electrophysiology study which induces and confirms the diagnosis of the arrhythmia for which ablation therapy is sought.
- "Non-complex" ablations include ablation for arrhythmias such as: AV nodal reentrant tachycardiaAV nodal reentrant tachycardiaAV nodal reentrant tachycardia , or atrioventricular nodal reentrant tachycardia, is a type of tachycardia of the heart. It is a type of supraventricular tachycardia , meaning that it originates from a location within the heart above the bundle of His. AV nodal reentrant tachycardia is the most...
, Accessory pathway mediated tachycardia, atrial flutterAtrial flutterAtrial flutter is an abnormal heart rhythm that occurs in the atria of the heart. When it first occurs, it is usually associated with a fast heart rate or tachycardia , and falls into the category of supra-ventricular tachycardias. While this rhythm occurs most often in individuals with...
. These procedures are usually performed using intracardiac catheters (as are used during an electrophysiology study), fluoroscopyFluoroscopyFluoroscopy is an imaging technique commonly used by physicians to obtain real-time moving images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an X-ray source and fluorescent screen between which a patient is placed...
(a real-time X-ray camera), and electrical recordings from the inside of the heart.
- "Complex" ablations include ablation for arrhythmias such as multifocal atrial tachycardiaMultifocal atrial tachycardiaMultifocal atrial tachycardia is a cardiac arrhythmia, specifically a type of supraventricular tachycardia."Multifocal atrial rhythm" is the condition in the absence of tachycardia.-Causes and epidemiology:It is more common in the elderly....
, atrial fibrillationAtrial fibrillationAtrial fibrillation is the most common cardiac arrhythmia . It is a common cause of irregular heart beat, identified clinically by taking a pulse. Chaotic electrical activity in the two upper chambers of the heart result in the muscle fibrillating , instead of achieving coordinated contraction...
, and ventricular tachycardiaVentricular tachycardiaVentricular tachycardia is a tachycardia, or fast heart rhythm, that originates in one of the ventricles of the heart...
. In addition to the apparatus used for a "non-complex" ablation, these procedures often make use of sophisticated computer mapping systems to localize the source of the abnormal rhythm and to direct delivery of ablation lesions.
Surgical Procedures: Pacemaker and Defibrillator implantation and follow up
- Implantation of single and dual chamber pacemakers and defibrillators
- Implantation of "biventricular" pacemakers and defibrillators for patients with congestive heart failure
- Implantation of loop recorders (implanted ECG recorders for long term monitoring of ECG to allow for diagnosis of an arrhythmia)
- Clinical follow up and reprogramming of implanted devices