Anti-NMDA receptor encephalitis associated with severe sinoatrial node dysfunction: three case reports and a review of the literature.
Tang E, Tang P, Wang W, Wang L • Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology • 2026
Sinus arrest represents a reversible yet critical complication of anti-NMDA receptor encephalitis, with sinus node dysfunction resolving within weeks following immunotherapy and, when applicable, tumor resection.
Key Findings
Results
Three patients with anti-NMDA receptor encephalitis developed sinus arrest with durations of 5.71, 9.23, and 6.20 seconds, occurring on hospital days 17, 6, and 15, respectively.
All three patients were retrospectively analyzed from the authors' institution.
Sinus arrest durations ranged from approximately 5.7 to 9.2 seconds.
The timing of sinus arrest onset varied from day 6 to day 17 of hospitalization.
One patient underwent teratoma resection and received a temporary pacemaker.
All three patients regained normal sinus rhythm after immunotherapy and achieved favorable clinical outcomes.
Results
A pooled cohort of 28 patients (3 index cases plus 25 from literature review) showed that sinus arrest in anti-NMDAR encephalitis predominantly affected young women and often coincided with seizures during the acute phase.
PubMed, Web of Science Core Collection, and Google Scholar were searched for reports published between January 2005 and January 2025.
Search terms included 'anti-N-methyl-D-aspartate receptor encephalitis,' 'cardiac arrest,' 'sinus node dysfunction,' 'sinus arrest,' 'sinus pause,' and 'asystole.'
Only cases with confirmed anti-NMDAR encephalitis, documented cardiac rhythm abnormalities, and sufficient clinical data were included.
Most patients in the pooled cohort were young women.
Sinus arrest generally manifested during the acute phase of the illness.
Results
Among the pooled cohort of 28 patients, 76.92% attained complete or partial recovery following immunotherapy, with tumor resection and temporary pacing used as clinically indicated.
Recovery rate of complete or partial recovery was 76.92% across 28 pooled patients.
Treatment approaches included immunotherapy, tumor resection where applicable, and temporary cardiac pacing.
Sinus node dysfunction resolved within weeks following immunotherapy and tumor resection.
The three index cases all achieved favorable clinical outcomes with immunotherapy.
Conclusions
Sinoatrial node dysfunction in anti-NMDAR encephalitis is identified as a reversible but life-threatening complication requiring early recognition and combined management.
The authors characterize sinus arrest as 'a reversible yet critical complication' of anti-NMDAR encephalitis.
Sinus node dysfunction resolved within weeks following appropriate treatment.
Early recognition and combined management (immunotherapy plus, when indicated, tumor resection and temporary pacing) are described as essential.
The study was motivated by the need to 'raise awareness of this rare but life-threatening complication.'
What This Means
This research describes a rare but dangerous heart complication that can occur in patients with anti-NMDA receptor encephalitis, a type of brain inflammation caused by the immune system mistakenly attacking brain receptors. The study combined three new patient cases with 25 previously published cases to understand this complication better. In all three new cases, patients experienced episodes where their heart's natural pacemaker (the sinoatrial node) temporarily stopped firing — pauses lasting roughly 6 to 9 seconds — which can be life-threatening. These episodes tended to happen alongside seizures during the most severe phase of the illness.
This research suggests that heart rhythm problems in anti-NMDA receptor encephalitis are not permanent. Across the combined group of 28 patients, about 77% achieved complete or partial recovery after receiving immunotherapy (treatments that calm the immune system's attack on the brain), and in some cases, surgical removal of an underlying tumor (such as a teratoma) that was triggering the immune response. Temporary cardiac pacemakers were used in some patients to manage the dangerous pauses in heartbeat while waiting for the underlying brain inflammation to respond to treatment.
The practical implication of this research is that doctors treating patients with anti-NMDA receptor encephalitis should be aware that severe, potentially fatal heart rhythm disturbances can occur, even in otherwise young and healthy patients. Because the condition is reversible with proper treatment, continuous cardiac monitoring during the acute phase of the illness is important, and the heart problems should be managed alongside aggressive treatment of the encephalitis itself rather than being viewed as a separate, permanent cardiac condition.
Tang E, Tang P, Wang W, Wang L. (2026). Anti-NMDA receptor encephalitis associated with severe sinoatrial node dysfunction: three case reports and a review of the literature.. Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. https://doi.org/10.1007/s10072-026-09154-6