Dorsal vagal nucleus involvement relates to QTc-prolongation after acute medullary infarction

Background: Infarction of the medulla has been associated with prolongation of the QTc, severe arrhythmia, and sudden cardiac death, yet the precise anatomical substrate remains uncertain. Aims: We sought to determine the possible anatomical structures relating to QTc-prolongation in patients with acute medullary infarction. Methods: We included 12 subjects with acute ischemic medullary infarction on brain MRI, who presented within 4.5 h from the last known well time, with a 90-day follow-up. For an unbiased lesion analysis, medullary infarcts were manually outlined on diffusion weighted MRI and co-registered with an anatomical atlas. Results: Nine out of 12 had QTc-prolongation. Qualitative and semi-quantitative comparisons were made between infarct location and QTc-prolongation. Among patients with QTc-prolongation, the greatest degree of congruence of the infarct location was over the dorsal vagal nucleus (DVN, 8 out of 9). There was a significant correlation between the number of sections showing infarction of the DVN and presence of QTc-prolongation (r = .582, p = .047). Among patients without QTc-prolongation, the maximum lesion overlap included the medial aspect of the gigantocelluar reticular nucleus of the reticular formation. Conclusion: We found that the DVN is a key anatomical substrate related to QTc-prolongation. Further studies with more patients and high-resolution, volumetric MRI are needed to confirm our findings.

Automated summary

This study aimed to determine the anatomical structures related to QTc-prolongation in patients with acute medullary infarction, and found that the dorsal vagal nucleus (DVN) is a key anatomical substrate for QTc-prolongation. Further studies with more patients and high-resolution, volumetric MRI are needed to confirm these findings.