Viral Encephalitis Associated With Reversible Asystole
We report a case of sinoatrial node block associated with syncopal episodes that required a temporary pacemaker. Magnetic resonance imaging (MRI) of the brain showed lesions of both temporal lobes consistent with viral encephalitis, presumably due to herpes simplex virus (HSV). The patient quickly recovered with intravenous acyclovir (Zovirax) therapy. Patients with presumed encephalitis might benefit from cardiac monitoring for possible associated cardiac arrhythmia. A permanent pacemaker is rarely required, since recovery is spontaneous in the majority of these cases.

Various electrocardiographic changes and arrhythmias have been known to occur with various central nervous system abnormalities, such as subarachnoid hemorrhage, increased intracranial pressure, and epilepsy. Of these, bradycardia and ST-T segment changes are well known. Because prolonged absence of sinoatrial node activity is uncommon, we report a case of prolonged sinoatrial block due to encephalitis.