(From “Ablation Technologies Worldwide Market, 2008-2017:Â Products, Technologies Markets, Companies and Opportunities.”Â Published 2008 by MedMarket Diligence, LLC. See link.)
Several types of energy-based therapies have a variety of applications to CV diseaseâ€”the number one killer in most of the world.
When the heart has to work too hard to maintain adequate blood output, it can begin to change shape, with the left ventricle (the heartâ€™s main pumping chamber) often growing larger, less flexible and weaker. Prolonged compensation for these impairments can change both the heart structure and its function. Remodeling of the heart results in errant signals transmitted from the SA node that cause unsynchronized heartbeats. These are treatable with a variety of energy-based therapies including implantable resynchronization devices and surgical ablation therapies. Energy is also being employed in the fight against CV disease as a means to open occluded vessels and revascularize damaged heart muscles.
The chart (â€œEnergy-Based Therapies for Cardiovascular Diseasesâ€) highlights symptoms and energy-based therapies for different cardiovascular diseases.
Atrial arrhythmias may be focal (arising from only one place in one of the atria) or multifocal (arising from many different places in the atria). Inappropriate sinus tachycardia is a relatively rare and generally harmless condition in which the heart is normal but the heart rate is unusually fast, both at rest and in response to physical activity. Treatment is available, but the cause is unknown.
Premature atrial contractions (PACs) are often referred to as premature supraventricular contractions. PACs are harmless irregular heart rhythms that generally do not need to be treated. They are often due to stress or use of substances such as caffeine and alcohol. They occur when one of the heartâ€™s upper chambers contracts prematurely in the heartbeat cycle. However, in some patients, ablation may be advisable to treat PACs before they can trigger atrial fibrillation.
Paroxysmal atrial tachycardia is a condition originating in the atria, in which the heartbeat increases for several minutes to a number of hours. Treatment may be necessary for short, sudden episodes that begin and end rapidly. Most people with this condition are young with normal hearts. The condition may be exacerbated by the use of even small amounts of caffeine or alcohol. This condition has also been associated with overly high levels of digitalis (a cardiotonic drug) in the bloodstream. Atrial flutter is a specific type of atrial tachycardia in which atria contract regularly, but extremely rapidly. Patients with atrial flutter may have as great a risk of stroke as patients with atrial fibrillation. Treatment such as surgical ablation is often recommended.
Atrial fibrillation (AF) is the result of rapid, disorganized signals in the atria that prompt the ventricles to contract irregularly. When the atria fibrillate (or quiver) instead of beating, blood is not effectively passed through the heartâ€™s chambers and may pool in the atria. A blood clot may form and may travel throughout the body, which could lead to a stroke or heart attack. With AF, electrical signals in the heartâ€™s upper chambers, or atria, cause the heart muscle to flutter wildly, which in turn reduces the efficiency of the ventricles. This allows blood to pool and form clots that can lead to strokes.
There are three main types of AF: paroxysmal (which starts and stops suddenly), persistent (which lasts longer and may require some medical intervention to terminate) and chronic or permanent. Chronic or permanent AF does not respond well to standard treatment.
Postoperative atrial fibrillation is one of the most common complications in cardiac surgery, occurring in 20%â€“50% of all patients within 2â€“4 days after heart surgery. Researchers estimate that postoperative atrial fibrillation costs the U.S. health system up to $1.5 billion dollars annually. Postoperative atrial fibrillation requires treatment before the patient is discharged from the hospital.
AF is the most common type of sustained arrhythmia, affecting 2 million people each year in the United States alone with annual incidence of new cases estimated at more than 700,000. It is estimated that AF affects over 4 million people in the developed world.
If left untreated, AF may lead to a variety of medical conditions, including stroke. Approximately 15% of strokes are a direct result of AF, a progressive disease that generally worsens over time. Since the incidence of AF increases as a population ages, the â€œgrayingâ€ of world populations will likely lead to a significant increase in the number of cases of chronic AF.
Treatment options include AV nodal ablation with subsequent pacemaker implantation; this has been used successfully for many years in certain patients with chronic AF. Biventricular pacing, an area of significant clinician interest, is sometimes indicated for heart failure (HF) patients. Medical literature suggests benefits of biventricular pacing for such patients versus conventional right-ventricular approaches. However, this is a relatively new field that has not yet been extensively studied. In a study published in the New England Journal of Medicine, researchers found that for older patients at risk of stroke from atrial fibrillation, treatments to control heart rhythm were no better at preventing death than treatments to control heart rate. But other data suggest that for people whose main concern is quality of life, ablation may provide substantial relief. In this treatment, energy is used to burn away specific, tiny areas of tissue, particularly those on veins from the lungs to the heart that trigger arrhythmia.
Doctors have long assumed that the best way to treat atrial fibrillation is to get the heart back to a regular rhythm and maintain it, using electric shock or strong drugs. Restoring normal rhythm, or sinus rhythm, was thought to reduce the risk of strokes and death, make patients feel better and allow them to stop taking blood thinners. If that method does not work, a second approach consisting of simpler, cheaper medications to slow down the heart rate and ease symptoms of palpitations, dizziness and shortness of breath is often employed. Patients treated with this regimen continue to experience abnormal rhythms and continue taking blood thinners to prevent blood clots.
The chart, â€œEnergy-Based Therapies for Atrial Arrhythmias,â€ shows products by energy modality and primary application being developed and approved for use in the treatment of atrial arrhythmias.
AtriCure (West Chester, OH; http://www.atricure.com)
ATS Medical (Minneapolis, MN; http://atsmedical.com)
Bard Electrophysiology (Lowell, MA; http://bardep.com)
Biosense Webster (Diamond Bar, CA; http://www.biosensewebster.com)
Biotronik (Berlin, Germany; http://www.biotronik.de)
Boston Scientific (Natick, MA; http://www.bostonscientific.com)
Cardima (Fremont, CA; http://www.cardima.com)
CryoCath Technologies (Montreal, Canada; http://www.cryocath.com)
CryoCor (San Diego, CA; http://www.cryocor.com)
Irvine Biomedical (See St. Jude Medical)
Johnson & Johnson (New Brunswick, NJ; http://jnj.com)
Medtronic (Minneapolis, MN; http://www.medtronic.com)
Spectrasonics (Wayne, PA; http://www.spectrasonics.com)
St. Jude Medical (St. Paul, MN; http://www.sjm.com)
Stereotaxis (St. Louis, MO; http://www.stereotaxis.com)
Data is drawn from “Worldwide Ablation Technologies 2007-2017, published September 2008, by MedMarket Diligence. See link for more details.