Patterns of cognitive recovery in sudden cardiac arrest survivors: the pilot study

To determine the prevalence, type, severity, and natural evolution of cognitive impairments in survivors of sudden cardiac arrest over time and to assess the relation of selected clinical and psychologic variables to those outcomes.

Longitudinal with repeated measures. Twenty-five consecutive patients underwent extensive neuropsychologic testing during hospitalization within 3 weeks of their initial cardiac arrest. Of these, 17 completed additional testing at 6 to 9 weeks, 12 to 15 weeks, and 22 to 25 weeks after the event.

Cardiac electrophysiologic services at a university teaching hospital, a community hospital, and home.

Orientation, attention, concentration, immediate recall, early retention, delayed recall, reasoning, motor speed, and motor regularity were measured.

During hospitalization, 72% of the patients had mild to severe impairments in one or more cognitive areas. Memory, particularly delayed recall, was the most common deficit. At 6 months after the arrest event, 29% (5 of 17) of the patients continued to be impaired, and all had deficits in delayed recall. Depression was significantly related to deficits in attention and delayed recall at 6 months only. Time to postarrest awakening was the most reliable predictor of long-term cognitive functioning in this patient sample.

A significant minority of sudden death survivors incur long-term cognitive impairments, particularly in delayed recall or short-term memory. The occurrence of long-term cognitive deficits in these patients can be estimated from the duration of unconsciousness after resuscitation (time-to-awakening).