Visual auras after heart treatment linked to brain injury
Visual auras following catheter ablation may signal brain injury, with new research linking symptoms to small lesions in brain regions responsible for vision.
The study found that patients who experienced migraine-like visual effects—such as flickering lights, flashes or blind spots—one month after undergoing catheter ablation for ventricular arrhythmias were more likely to have brain lesions visible on MRI scans the day after the procedure.
These lesions, often called “asymptomatic cerebral emboli”, may in fact cause delayed symptoms. Catheter ablation is a minimally invasive procedure used to treat heart rhythm disorders.
Researchers from the University of California San Francisco randomly assigned patients to one of two ablation methods: a transseptal approach, which involves puncturing the wall between the heart’s upper chambers, or a retrograde approach via the aortic valve.
MRI scans taken the following day showed small lesions in both groups.
However, only those in the occipital and parietal lobes—regions that process vision—were associated with visual aura symptoms reported a month later.
Senior author Gregory Marcus said: “Those patients with migraine-related visual auras were significantly more likely to exhibit an acute brain embolism in their occipital or parietal lobes attributed to the procedure.
“These data suggest that visual auras that commonly occur with migraines may actually signal brain injury or little strokes.
“This finding could change the whole paradigm of treatment, perhaps focusing more on prevention of blood clots.”
Although previous theories linked a transseptal puncture to these symptoms—potentially due to clots or chemicals bypassing the lungs—this study found no evidence that the procedural route affected the likelihood of aura development.
In many cases, brain lesions visible on scans the day after the procedure were no longer detectable one month later when symptoms appeared, suggesting that healing may occur even though delayed neurological effects persist.
First author Adi Elias said: “We know that these brain lesions are seen after very common procedures, including after coronary angiograms, after transcutaneous replacement of aortic valves, after ablations for AF and ventricular arrhythmias, and are often referred to as ‘ACEs’—asymptomatic cerebral emboli.
“Our data show they are not asymptomatic or clinically silent.
“It may be the case that we haven’t known what to look for and assessed for symptoms immediately without enough time for the subsequent visual auras that would occur.”
The researchers note that while the findings may have relevance for migraine sufferers, the study was focused specifically on patients undergoing ablation for ventricular arrhythmias.
