New targeting technology improves outcomes for patients with atrial fibrillation
The left panel shows the eye of a hurricane. The right panel shows the striking similarity of the rotor or localized source of an arrhythmia in a patient with atrial fibrillation. Ablation targeted at these rotors or "eyes of the storm" successfully terminated and eliminated atrial fibrillation in the CONFIRM trial. Credit: UCSD/UCLA
In a landmark study of atrial fibrillation, researchers from UCLA, UC San Diego and Indiana University report having found for the first time that these irregular heart rhythms are caused by small electrical sources within the heart, in the form of electrical spinning tops ("rotors") or focal beats.
Importantly, they found a way of detecting these key electrical sources and of shutting them down in minutes using a precisely targeted therapy with long-lasting results.
The team, which included cardiologists, physicists and bioengineers, reports the findings in the July 19 issue of the Journal of the American College of Cardiology as part of the CONFIRM trial (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation).
Currently, many atrial fibrillation patients treated with standard therapies will experience a recurrence due to the difficulty of finding the arrhythmia's source. The new research will help cardiologists better target and treat arrhythmias.
The CONFIRM study examined 107 patients with atrial fibrillation who had been referred for a non-surgical catheter ablation procedure. During this procedure, doctors thread a wire with a metal-tipped catheter through the body, from a vein in the groin to the heart, to apply heat to the area of the heart producing the arrhythmia to stop it.
In one group of patients, the team used the new technique to help perform very small, precise burns called focal impulse and rotor modulation, or FIRM that were aimed directly at the fundamental source of the arrhythmia: the tiny electrical disturbances in the heart called focal beats or 'rotors' that look like mini-tornadoes or spinning tops. Rotors can be likened to an "eye of a storm" shown in this study to cause atrial fibrillation. Remarkably, this new procedure shut down or very significantly slowed atrial fibrillation in 86 percent of patients in an average of just 2.5 minutes.
As a comparison, conventional catheter procedures were performed in a second group of patients. Since this approach is less targeted, it involved hours of treatment over larger regions in the heart and often did not shut down the atrial fibrillation.
To track outcomes, patients received an implanted ECG monitor that very accurately assessed their heart rhythms over time. The researchers found that after two years, the FIRM-guided group had an 82.4 percent freedom from atrial fibrillation episodes, compared with only 44.9 percent freedom in the group that received standard therapy.
The new targeted method demonstrated an 86 percent improvement over the conventional method.
"We are very excited by this trial, which for the first time shows that atrial fibrillation is maintained by small electrical hotspots, where brief FIRM guided ablation can shut down the arrhythmia and bring the heart back to a normal rhythm after only minutes of ablation," said lead author Dr. Sanjiv Narayan, a professor of medicine at UC San Diego, visiting professor at the UCLA Cardiac Arrhythmia Center, and director of electrophysiology at the San Diego Veterans Affairs Medical Center.
"The results of this trial, with an 80 percent ablation success rate after a single procedure, are very gratifying," said study author Dr. Kalyanam Shivkumar, director of the UCLA Cardiac Arrhythmia Center and a professor of medicine and radiological sciences at UCLA. "This is the dawn of a new phase of managing this common arrhythmia that is mechanism-based."
Journal reference: Journal of the American College of Cardiology
Provided by University of California, Los Angeles
- UCSD uses heat energy to fix odd heart beat Feb 17, 2012 | not rated yet | 0
- Cryoablation used to successfully treat atrial fibrillation at the Montreal Heart Institute May 11, 2011 | not rated yet | 0
- The Medical Minute: Putting the freeze on abnormal heart beats Feb 25, 2009 | not rated yet | 0
- Freeze and desist: Disabling cardiac cells that can cause arrhythmia Sep 12, 2011 | not rated yet | 0
- Catheter ablation benefits younger adults with irregular heartbeat Sep 22, 2010 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Relating physics forces and entropy
52 minutes ago Consider proton and electron are seperated in space at some finite distance.Now suppose they released then the decrease in potential energy equals...
Force Between Two Concentric Solenoids
4 hours ago Imagine a finite length solenoid with outer radius R1 and inner radius R2. This solenoid has a time-varying current going though it. This solenoid is...
Synchrotron, question about insertion devices and electron velocity
4 hours ago When an electron enters an insertion device (wiggler and undulator) from the storage ring in a synchrotron the tangential velocity is equal to the...
Equating differentials => equating coefficients
6 hours ago Hi all, In thermodynamics one often has equations like A dx + B dy = ∂f/∂x dx + ∂f/∂y dy From which follows A = ∂f/∂x B = ∂f/∂y
The idea behind a reverse shock
12 hours ago So in a supernova explosion for example (5th slide) http://www.astro.princeton.edu/~burrows/classes/541/blastwavesChisari.pdf Ambient medium is...
Guass's Law for a charge distribution
12 hours ago First, this is not a homework question, just something I've been confused about for some time. I understand how to use Guass's law in many ways but...
- More from Physics Forums - Classical Physics
More news stories
Heart failure accelerates the aging process and brings on early andropausal syndrome (AS), according to research presented today at the Heart Failure Congress 2013. AS, also referred to as male 'menopause', was four times ...
Cardiology 17 hours ago | 5 / 5 (1) | 1
Mortality and length of stay are highest in heart failure patients admitted in January, on Friday, and overnight, according to research presented today at the Heart Failure Congress 2013. The analysis of nearly 1 million ...
Cardiology 17 hours ago | not rated yet | 0
Coenzyme Q10 decreases all cause mortality by half, according to the results of a multicentre randomised double blind trial presented today at Heart Failure 2013 congress. It is the first drug to improve heart failure mortality ...
Cardiology 17 hours ago | 5 / 5 (5) | 5
Transcatheter aortic valve implantation (TAVI) is effective and safe in Asian patients, according to early experience based on first results from a multicentre Asian registry reported at EuroPCR 2013.
Cardiology May 24, 2013 | not rated yet | 0
Routinely measuring fractional flow reserve (FFR) using pressure wire assessment during coronary angiography for diagnosis of chest pain leads to significant changes in the management of one in four patients, according to ...
Cardiology May 24, 2013 | not rated yet | 0
(HealthDay)—Animals make great companions for senior citizens, but elderly people who always drive with a pet in the car are far more likely to crash than those who never drive with a pet, researchers have ...
9 hours ago | not rated yet | 1
(AP)—Department of Justice lawyers have again asked a federal appeals court in New York to delay lifting age restrictions and prescription requirements on an emergency contraceptive popularly known as the morning-after ...
17 hours ago | not rated yet | 0
(Medical Xpress)—A research team, led by Jeremy Barr, a biology post-doctoral fellow, unveils a new immune system that protects humans and animals from infection.
May 20, 2013 | 4.8 / 5 (31) | 9 |
Until now, little was scientifically known about the human potential to cultivate compassion—the emotional state of caring for people who are suffering in a way that motivates altruistic behavior.
May 22, 2013 | 5 / 5 (4) | 6 |
Salamanders' immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists have ...
May 20, 2013 | 4.9 / 5 (7) | 5 |
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
May 24, 2013 | 4 / 5 (4) | 4 |