Voxelwise distribution of acute ischemic stroke lesions in patients with newly diagnosed atrial fibrillation: Trigger of arrhythmia or only target of embolism?

Abstract

ObjectiveAtrial fibrillation (AF) is frequently detected after ischemic stroke for the first time, and brain regions involved in autonomic control have been suspected to trigger AF. We examined whether specific brain regions are associated with newly detected AF after ischemic stroke. MethodsPatients with acute cerebral infarctions on diffusion-weighted magnetic resonance imaging were included in this lesion mapping study. Lesions were mapped and modeled voxelwise using Bayesian Spatial Generalised Linear Mixed Modeling to determine differences in infarct locations between stroke patients with new AF, without AF and with AF already known before the stroke. Results582 patients were included (median age 68 years; 63.2% male). AF was present in 109/582 patients [(18.7%); new AF: 39/109 (35.8%), known AF: 70/109 (64.2%)]. AF patients had larger infarct volumes than patients without AF (mean: 29.7 ± 45.8 ml vs. 15.2 ± 35.1 ml; p<0.001). Lesions in AF patients accumulated in the right central middle cerebral artery territory. Increasing stroke size predicted progressive cortical but not pontine and thalamic involvement. Patients with new AF had more frequently lesions in the right insula compared to patients without AF when stroke size was not accounted for, but no specific brain region was more frequently involved after adjustment for infarct volume. Controlled for stroke size, ConclusionsIn the search for brain areas potentially triggering cardiac arrhythmias infarct size should be accounted for. After controlling for infarct size, there is currently no evidence that ischemic stroke lesions of specific brain areas are associated with new AF compared to patients without AF. This challenges the neurogenic hypothesis of AF according to which a relevant proportion of new AF is triggered by ischemic brain lesions of particular locations.

Patterns of Infarction on MRI in Patients With Acute Ischemic Stroke and Cardio-Embolism: A Systematic Review and Meta-Analysis

“…Larger infarct volumes have been associated with CE source of stroke, in multiple studies ( 24 , 29 – 31 ). In addition to infarct size, subsequent infarct growth, and hemorrhagic transformation are also strongly predictive of underlying CE source.…”

“…Studies looking at anterior circulation infarcts did not show a clear predilection for CE stroke as opposed to other stroke etiologies ( 21 – 23 ). A study by Rizos et al, utilizing lesion mapping techniques, showed a higher probability of CE infarcts in the right insula compared to other regions ( 24 ).…”

Vorhofflimmern: Diagnostik und was ein Neurologe darüber wissen sollte.

“…neurogene VHF Hypothese [14]). Dem gegenüber steht eine rezente MRT-basierte lesion-mapping Studie, welche keine Assoziation umschriebener infarzierter Hirnregionen mit neu diagnostiziertem VHF nach stattgehabtem Schlaganfall nachweisen konnte [15]. Hinzu kommt, dass sich kardiovaskuläre Risikofaktoren, echokardiografische Befunde und auch die Schlaganfallschwere zwischen Schlaganfallpatienten mit neuem und mit schon vor einem Schlaganfall bekanntem VHF nicht unterscheiden [9].…”

Table_1.DOCX

“…In two out of three studies (29,30), the baseline infarct volume with statistically significantly higher in CE compared to non-CE stroke. Rizos et al (24) reported a mean baseline infarct volume of 41.2 ml, which was likewise significantly higher than patients with non-CE source of stroke (15.1 ml).…”

“…Studies looking at anterior circulation infarcts did not show a clear predilection for CE stroke as opposed to other stroke etiologies (21)(22)(23). A study by Rizos et al, utilizing lesion mapping techniques, showed a higher probability of CE infarcts in the right insula compared to other regions (24).…”