The Heart Treatment that May be Linked to Cognitive Decline
A common treatment for irregular heartbeat might cause brain lesions under some circumstances, according to new research.
The treatment, catheter ablation, is risky when performed on the left side of the heart, say researchers from the University of California San Francisco. Additionally, investigators found evidence that the brain lesions may be linked to cognitive decline – and that in turn indicates 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 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.