When the Brain Slows the Heart - Herpes Encephalitis and Sinus Arrest

A 54-year-old man was admitted to the hospital with a ten-day history of fever, confusion and fatigue. One week prior to admission he had a transient loss of consciousness. He reported standing up after a strained defecation, after which he lost consciousness.

Upon admission, he was alert and hemodynamically stable, with a temperature of 39°C. Physical examination was otherwise normal and 12-leads electrocardiogram (ECG) was unremarkable.

An initial workup did not reveal the source of his fever. Thereafter, a gradual cognitive impairment, aphasia and facial asymmetry were noticed, prompting further investigation by CT angiography(CTA) of the brain and neck, lumbar puncture and empiric antiviral treatment with intravenous Acyclovir. CTA demonstrated changes at the left hemispheric blood vessels correlating with cerebral vasculitis or angiitis Lumbar puncture showed mildly elevated protein level , normal glucose level ,, and marked pleocytosis with a lymphocytic predominance PCR analysis from the cerebrospinal fluid(CSF) confirmed the presence of herpes simplex virus (HSV).

Due to his syncopal event, a 24 hours Holter ECG monitoring was performed a day before the LP test. The Holter documented five episodes of sinus arrest; prominent ones being 11 and 32 seconds at 06:13 and 10:09 o`clock accordingly. During this last sinus arrest, the patient had a transient loss of consciousness that was noticed by the staff. He was urgently transferred to the intensive cardiac care unit(ICCU) for further assessment and monitoring. During his stay in the ICCU, his cognitive impairment and focal deficits resolved and the fever subsided. He had no further episodes of syncope or documented bradycardia. Repeated echocardiography was also normal. Due to the potentially reversible underlying cause and complete recovery of his symptoms and heart rate, the decision was made not to implant a cardiac pacemaker.Subsequent Holter ECG revealed normal heart rate without any evidence of bradycardia.