Electrophysiology

Overview

Electrophysiology (EP) is a cardiac specialty that involves the diagnosis and treatment of heart rhythm disorders. Patients with rhythm abnormalities often have diseases of the electrical system of their heart. Several of these diseases fall under the category of cardiomyopathy, in which the heart muscle becomes abnormally large, thick or stiff. In some cases, the heart’s muscle tissue becomes scar tissue. The heart weakens as cardiomyopathy progresses, and has more difficulty pumping blood throughout the body and keeping a steady electrical rhythm. The result may be heart failure or disrhythmia/arrhythmia (irregular heartbeat). Heart failure may then cause fluid build-up in the lungs, abdomen or lower extremities. A weakened heart also may causeheart valve problems.

The heart rhythm is set by a fine tuned, elaborate electrical system composed of specialized cardiac cells that coordinate the contractions of the upper and lower chambers of the heart. A normal heart rate is 60 to 100 beats per minute, a slow heart rate, or bradyarrhythmia, is less than 60 beats per minute, and a rapid heart rate, or tachyarrhythmia, is faster than 100 beats per minute. Disrhythmia and abnormal heart rates don't necessarily occur together. Disrhythmia can occur with a normal heart rate, or with heart rates that are slow or rapid.

Causes

Cardiomyopathy may be an acquired or inherited disease. Often, its cause is unknown. Depending on the specific condition, disrhythmia may be caused by:

  • Abnormal contractions of the atria (the heart’s upper chambers) or ventricles (lower chambers)
  • Rapid circuits in the atria
  • Electrical impulses originating in the wrong area of the heart
  • Abnormality in the heart’s conduction (electrical) system
  • Malfunction of the sinoatrial node (the heart's natural pacemaker)
  • An extra electrical pathway
  • Scar tissue from previous heart attacks

Symptoms

For cardiomyopathy, if there are no symptoms, no treatment is needed. However, when symptoms are present, the disease progresses, with severe symptoms and serious complications. Heart failure symptoms are the most common, and usually develop slowly. However, sometimes symptoms may start suddenly and severely.For dysrhythmia, symptoms may include fatigue, palpitations, too fast or too slow heartbeat, shortness of breath, and heart attacks.

Types

Cardiomyopathy can take the following forms: 

  • Dilated cardiomyopathy   ̶   The heart muscle itself is the problem, not any condition caused by a heart attack or valve problem. This type also can affect the lungs or liver. Its most common causes are heart disease due to high blood pressure as well as narrowed arteries. This condition is found most frequently in adult males.
     
  • Hypertrophic cardiomyopathy (HCM)   ̶   is very common, affecting people of any age, men and women equally, and is a common cause of sudden cardiac arrest (SCA) in young people. HCM occurs if heart muscle cells enlarge and cause the ventricle walls (usually the left ventricle) to thicken, blocking blood flow out of the ventricle (obstructive hypertrophic cardiomyopathy). HCM usually is inherited.

  • Restrictive cardiomyopathy   ̶   affects mostly older adults. The disease causes the ventricles to become rigid because abnormal tissue, such as scar tissue, replaces the normal heart muscle. The ventricles can no longer function properly, and the atria become enlarged. Blood flow in the heart is reduced, and can cause problems such as heart failure or disrhythmia.

  • Arrhythmogenic right ventricular dysplasia (ARVD)   ̶   In this rare condition, which affects adolescents and young adults, muscle tissue in the right ventricle dies and is replaced with scar tissue. That interrupts the heart's electrical signals and causes disrhythmia. Palpitations and fainting after physical activity are two of the symptoms associated with ARVD.

  • Myocarditis   ̶   is an inflammation of the heart muscle. This uncommon disorder usually is caused by a viral, bacterial or fungal infection that reaches the heart, and can lead to heart failure.

  • Unclassified cardiomyopathy   ̶   This category includes stress-induced cardiomyopathy (“broken heart” syndrome). 

Disrhythmia can include:

  • Atrial fibrillation (“A-fib”)  –  Atrial fibrillation, the most common disrhythmia in the world, causes the atria to contract abnormally. Approximately 2 million to 3 million Americans suffer from this debilitating disrhythmia that often leads to symptoms of fatigue, palpitations and shortness of breath and can put the patient at risk for strokes.
     
  • Atrial flutter  –  This disrhythmia is caused by one or more rapid circuits in the atrium. Atrial flutter is usually more organized and regular than atrial fibrillation.

  • Atrial tachycardia –  Atria tachycardia occurs when the electrical impulses that regulate the heartbeat originate in the wrong area of the heart.

  • Paroxysmal atrial tachycardia (PAT)  –  In PAT, the heart beats too fast because there is an abnormality in its conduction (electrical) system. Episodes of paroxysmal atrial tachycardia can be brief but sometimes can last for hours and be very serious.

  • Premature atrial contractions (PAC)  –  These contractions in the atria occur too early in the rhythm sequence, because abnormal electrical impulses signal it to beat prematurely. PAC are very common and can happen in a healthy patient.

  • Sick sinus syndrome (SSS)  –  Not a specific disease, SSS is a group of signs or symptoms indicating that the sinoatrial node (the heart's natural pacemaker) is not functioning properly. Some patients with SSS also have rapid heartbeats, or the heartbeat alternates between too fast and too slow.

  • Sinus tachycardia  –  This disrhythmia has an elevated rate of impulses originating from the sinoatrial node. Symptoms of sinus tachycardia are defined as a heart rate greater than 100 beats per minute in an average adult.

  • Supraventricular tachycardia (SVT)  –  This means that from time to time the heart's electrical system doesn't work properly and your heart beats very fast for a reason other than exercise, high fever, or stress. Types of SVT include:

    • Atrioventricular nodal reentrant tachycardia (AVNRT)  –  This is the most common type of supraventricular tachycardia.

    • Atrioventricular reciprocating tachycardia (AVRT)  –  This occurs when there is an extra electrical pathway linking the upper (atria) and lower (ventricle) chambers of the heart.

    • Wolff-Parkinson-White syndrome  –  This occurs when an extra electrical pathway is present in the heart. It is one of the most common causes of fast heart rate problems in infants and children, and sometimes runs in families, but most people with this syndrome do not necessarily have other heart problems.

  • Ventrical arrhythmia  –  This condition involves abnormal rapid heart rhythms originating in the lower chambers of the heart, and include ventricular tachycardia (VT) and ventricular fibrillation (VF). Both are life-threatening disrhythmias, most commonly associated with heart attacks or scarring of the heart muscle from previous heart attacks.

  • Ventricular tachycardia (VT)  –  The symptoms of ventricular tachycardia are a fast heart rhythm originating in the lower ventricles. If left untreated, some forms of ventricular tachycardia may get worse and lead to ventricular fibrillation, a condition that can be life-threatening.

  • Ventricular fibrillation (VF)  –  This occurs when there is uncoordinated contraction of the cardiac muscle of the ventricles that makes them quiver rather than contract properly. This activity is not felt by the patient.

  • Premature supraventricular contractions  –  These premature contractions originate from the ventricles and occur before the regular heartbeat.

Risks

Anyone can develop cardiomyopathy, but different types of cardiomyopathy are present in different age groups.

Disrhythmia is common in older adults, most seriously in those over 60, and the number of incidences is increasing. One factor is that older adults often have heart disease and other health problems that can lead to disrhythmia. They also may be more reactive to the side effects of medicines, some of which can cause disrhythmia. Some types of disrhythmia, such as paroxysmal supraventricular tachycardia (PSVT), including Wolff-Parkinson-White syndrome, are more frequent in children and young adults.

Disrhythmia is more common in people who have had heart attacks, heart failure, cardiomyopathy, abnormal heart tissue, leaking or narrowed heart vessels, congenital heart defects, high blood pressure, heart infections, diabetes, sleep apnea, thyroid problems, heart surgery, cocaine or amphetamine use, and blood chemical imbalance.

 

Tests and diagnosis

Some types of tests that may be used to diagnose cardiomyopathy are:

  • Tests to diagnose autoimmune illnesses
  • Antibody test to identify infections such as Lyme disease and HIV
  • Iron tests of the blood
  • Test to identify thyroid problems
  • Echocardiogram (ultrasound of the heart)
  • Cardiac stress tests
  • Chest X-ray
  • Coronary angiogram 
  • CT scan
  • MRI
  • Nuclear heart scan
  • Heart biopsy, which is rarely done.

Our combination of expert physicians and innovative technology will help you with any heart rhythm needs. The electrophysiology (EP) team (cardiologists who manage heart rhythm disturbances) provides a comprehensive evaluation and treatment program designed to provide the best customized diagnostic and treatment approach for you.

Patients who require an electrophysiology study often have symptoms of heart palpitations, shortness of breath, fainting, or chest pain. In this test, insulated electric catheters are placed inside the heart to study its electrical system. A small catheter is inserted through the groin or neck into the heart. This gives the physician the ability to find the origin of a disrhythmia within the heart tissue and determine the best way to treat it.

We use the latest technology to work with you and your primary care physician or cardiologist. To help analyze your heart’s rhythm, our electrophysiologists may use one or more of the following tests:

  • Event recorder —  activated during episodes of fibrillation and records the heart rhythm at that time
  • Holter monitor —  a machine, worn for 24 to 48 hours, that continuously records the heart's rhythms during normal activity
  • Loop recorder —  a similar device that is worn for two weeks or longer
  • Tilt-table studies —  a test for people who experience fainting (syncope); the patient lies on a flat table and is tilted at various angles while heart rate and blood pressure are closely monitored.
  • T-wave alternans study —  the patient undergoes an electrocardiogram, where electrodes are placed on the body to record the electrical activity of the heartbeat, and any differences between beats are measured

Treatment

Our board-certified electrophysiologists  provide comprehensive evaluations and treatment strategies for all forms of disrhythmia and heart rhythm abnormalities. There are surgical and nonsurgical treatments for cardiomyopathy. 

  • Non-surgical treatments include:
    • Lifestyle management
    • Medications
    • Nonsurgical procedures
  • Surgical options include:
    • Invasive surgery
    • Implanted devices to correct disrhythmia
    • Heart transplant, in severe cases

Diagnostic and treatment services include:

  • LARIAT (left atrial appendage occlusion)
  • Cardioversion —  electricity or drugs are used to normalize heart rhythm
  • Ablation —  a catheter (a thin, flexible tube) is inserted into the patient’s blood vessel and gently guided to the heart, so a physician can carefully use energy to destroy malfunctioning tissue. Abnormal rhythms can be permanently treated with ablation using freezing energy (cryoablation) or heating energy (radiofrequency ablation), or a laser.
  • Noninvasive testing and heart monitoring
  • Lead management program, including lead extraction
  • Clinical trials, including the WATCHMAN™ for atrial fibrillation
  • Pacemaker, defibrillator and biventricular device implantation
  • Cardiac resynchronizatioon therapy 

Prevention

  • Monitor changes in your symptoms, heart rate, pulse, blood pressure and weight
  • Limit your alcohol and salt (sodium) intake

Why choose us?

Our electrophysiologists are highly skilled specialists trained to diagnose and treat all types of heart rhythm disorders. That’s why patients rely on us for quality care from an expert. We are advancing electrophysiology with regionally and nationally recognized specialists who are committed to treating the full spectrum of heart rhythm disorders.

 

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