Nav: Home

Therapy for abnormal heartbeats may cause brain injury

January 24, 2017

A common treatment for irregular heartbeats known as catheter ablation may result in the formation of brain lesions when it is performed on the left side of the heart, according to new research at UC San Francisco. Importantly, there also is evidence these lesions may be associated with cognitive decline, meaning they may not be benign.

In a small study of patients undergoing catheter ablation for common abnormal heartbeats from the lower chamber of the heart (premature ventricular contractions (PVCs)), researchers found a significantly higher rate of seemingly asymptomatic brain injury due to embolism among the patients whose therapy occurred on the left ventricle of the heart, which supplies blood to the brain, compared to patients whose therapy was conducted on the right ventricle, which pumps blood to the lungs.

The researchers recommend further study on the impact of these lesions and strategies to avoid them. Their study appears online Jan. 24, 2017, in the American Heart Association journal Circulation.

"The rate of asymptomatic emboli in similar procedures for other types of heart rhythm disturbances tends to be 10-20 percent," said study senior author Gregory Marcus, MD, MAS, a UCSF Health cardiologist and director of clinical research in the UCSF Division of Cardiology.

"Our study finding is relevant to a large number of patients undergoing this procedure and hopefully will inspire many studies to understand the meaning of and how to mitigate these lesions," Marcus said. "This also will become an important consideration as we think about how to optimally help the large number of people out there with PVCs."

PVCs are extra, abnormal heartbeats originating in the ventricles. They disrupt the heart's regular rhythm and typically have not been a reason for concern.

However, recent research by Marcus and his colleagues demonstrated that PVCs are an important predictor of heart failure and mortality and can cause very bothersome symptoms. Further, such early beats occurring continuously for more than 30 seconds is a potentially serious cardiac condition called ventricular tachycardia (VT).

Given growing recognition of all these phenomena, catheter ablation for PVCs and VT is mainstream and becoming even more common, with well more than 235,000 such procedures performed annually. It is also increasingly used for patients with heart failure due to weak heart muscle that may improve after frequent PVCs are eradicated.

In this minimally invasive procedure, thin, flexible wires called catheters are inserted into a vein and threaded into the heart. The tip of the catheter either delivers heat or extreme cold to destroy tissue responsible for starting or maintaining the abnormal heart rhythm. The procedure can result in the complete and permanent cessation of the PVCs/VT that are targeted and is generally considered low risk.

An "embolism" occurs when an object moves through the bloodstream from one part of the body to another. Catheters placed in the left side of the heart may lead to brain injury if something that can occlude a blood vessel is either formed, such as a blood clot, or dislodged by the catheter and travels to the brain. Because the right side of the heart leads to the lungs, not the brain, brain emboli generally are not a concern.

Data from previous left heart-based procedures has shown that brain injury thought to be due to embolism rarely occurs. Those emboli generally have been attributed to either issues with the particular patient populations studied or the risks inherent to treating another common heart rhythm disturbance, atrial fibrillation, with ablation.

In this Circulation study, Marcus and his colleagues enrolled 18 patients scheduled for VT or PVC ablation over a nine-month period. The average patient age was 58, with half being men, half having a history of hypertension, and a majority having no known vascular disease or heart failure. Most patients were generally healthy.

Left ventricular (LV) ablation was performed in 12 patients compared to a control group of six patients who underwent right ventricular (RV) ablation. Pre- and post-procedural brain magnetic resonance imaging (MRI) was performed on each patient within a week of the ablation, along with a complete neurological examination.

Overall, seven of the 12 patients (58 percent) who underwent LV ablation experienced 16 brain embolisms combined, compared to zero patients who underwent the RV ablation. Seven of 11 patients (63 percent) who underwent a retrograde approach to their LV ablation developed at least one new brain lesion.

"Further research is important to understanding the long-term consequences of these lesions and determining optimal strategies to avoid them," said lead author Isaac Whitman, MD, UCSF cardiac electrophysiology fellow.
-end-
Other UCSF contributors to the Circulation study were Rachel Gladstone, cardiology research assistant; Nitish Badhwar, MD, professor of medicine; Henry Hsia, MD, professor of medicine; Byron Lee, MD, professor of medicine; S. Andrew Josephson, MD, Carmen Castro Franceschi and Gladyne K. Mitchell Neurohospitalist Distinguished Professor of Neurology; Karl Meisel, MD, assistant professor of neurology; William Dillon Jr., MD, Elizabeth A. Guillaumin Professor of Radiology; Christopher Hess, MD, PhD, professor of radiology; and Edward Gerstenfeld, MD, professor of medicine and holder of the Melvin M. Scheinman Endowed Chair in Cardiology. Financial support was provided by the Joseph Drown Foundation.

UC San Francisco (UCSF) is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy; a graduate division with nationally renowned programs in basic, biomedical, translational and population sciences; and a preeminent biomedical research enterprise. It also includes UCSF Health, which comprises top-ranked hospitals, UCSF Medical Center and UCSF Benioff Children's Hospitals in San Francisco and Oakland - and other partner and affiliated hospitals and healthcare providers throughout the Bay Area.

University of California - San Francisco

Related Heart Failure Articles:

Type 2 diabetes may affect heart structure and increase complications and death among heart failure patients of Asian ethnicity
The combination of heart failure and Type 2 diabetes can lead to structural changes in the heart, poorer quality of life and increased risk of death, according to a multi-country study in Asia.
Preventive drug therapy may increase right-sided heart failure risk in patients who receive heart devices
Patients treated preemptively with drugs to reduce the risk of right-sided heart failure after heart device implantation may experience the opposite effect and develop heart failure and post-operative bleeding more often than patients not receiving the drugs.
How the enzyme lipoxygenase drives heart failure after heart attacks
Heart failure after a heart attack is a global epidemic leading to heart failure pathology.
Novel heart pump shows superior outcomes in advanced heart failure
Severely ill patients with advanced heart failure who received a novel heart pump -- the HeartMate 3 left ventricular assist device (LVAD) -- suffered significantly fewer strokes, pump-related blood clots and bleeding episodes after two years, compared with similar patients who received an older, more established pump, according to research presented at the American College of Cardiology's 68th Annual Scientific Session.
NSAID impairs immune response in heart failure, worsens heart and kidney damage
Non-steroidal anti-inflammatory drugs, or NSAIDs, are widely known as pain-killers and can relieve pain and inflammation.
Heart cell defect identified as possible cause of heart failure in pregnancy
A new Tel Aviv University study reveals that one of the possible primary causes of heart failure in pregnant women is a functional heart cell defect.
In heart failure, a stronger heart could spell worse symptoms
Patients with stronger-pumping hearts have as many physical and cognitive impairments as those with weaker hearts, suggesting the need for better treatment.
Patients with common heart failure more likely to have lethal heart rhythms
New Smidt Heart Institute Research shows that patients with Heart Failure with Preserved Ejection Fraction (HFpEF) are more likely to have lethal heart rhythms.
Why does diabetes cause heart failure?
A Loyola University Chicago Stritch School of Medicine study reveals how, on a cellular level, diabetes can cause heart failure.
Oxygen therapy for patients suffering from a heart attack does not prevent heart failure
Oxygen therapy does not prevent the development of heart failure.
More Heart Failure News and Heart Failure Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.