Most people who experience cardiac arrest do not survive. Among those who do, there is risk of neurologic dysfunction, brain injury, disorders of consciousness, neurocognitive deficits, changes in quality of life, as well as physical and psychological wellbeing.

Neurological Consequences of Cardiac Arrest Survival

The most common neurological consequence of cardiac arrest is known as hypoxic-ischemic brain injury. This type of injury, which is a leading cause of significant disability or death following resuscitation, is named for the factor that triggers it (lack of oxygen or hypoxia) and its impact on the cells, known as ischemia. This is followed by reperfusion injury. This type of brain injury occurs when the heart is restarted, and results from the interaction of oxygen, which is now returned to the brain, with highly reactive metabolites produced in the brain during the period of cardiac arrest.1 The end result is neuronal damage and death.

The longer a person remains with limited or no oxygen or blood flow to the brain, the greater the accumulation of these reactive metabolites, and the greater the potential for reperfusion injury when oxygen returns to the brain. In addition to cell death, chemical changes in the brain during cardiac arrest and reperfusion can trigger cerebral edema, or swelling in the brain, along with a severe constriction of blood vessels (vasospasm) in the brain. Both disrupt the flow of blood and delivery of oxygen to the brain, further compounding the injury.

Other cardiac arrest survivors may experience brain injuries as a result of decreased blood flow and oxygen to the brain, such that specific portions of the brain are impacted. These impacts may be permanent or they may improve over time, and include movement disorders, memory loss or impairment, speech difficulties, weakness or immobility, and cognitive impairments including difficulties with attention, concentration, and visual-motor skills.

Functional Deficits Following Cardiac Arrest Survival

Neurological damage sustained during and after resuscitation can result in a range of physical and functional deficits. These deficits often impact quality of life and may affect an individual’s ability to resume work and live independently. A high percentage of cardiac arrest survivors are affected by some degree of decrease in functional abilities—estimates place the incidence at more than half of patients who survive cardiac arrest and are discharged from the hospital. In some cases, these challenges are related to brain injury sustained during the post-cardiac arrest period, where others stem from the initial cause of the cardiac arrest itself, such as a traumatic accident.

The specific parts of the brain that were damaged, and to what degree, during cardiac arrest dictate the type and severity of difficulties patients experience as they return to their lives. Among the most common challenges are changes or limits in mobility, difficulty completing basic activities of daily living, reduced executive functioning—including concentration and decision-making—and difficulties with balance and motor coordination.

Rehabilitative therapies can improve a person’s functional status in some cases, but these impairments often impact their ability to work, live independently, and engage in even the simplest daily activities, such as bathing, getting dressed, and interacting socially. As a result, psychological difficulties are also included in assessments of functional deficits following cardiac arrest and resuscitation, as many people may struggle with negative emotional repercussions during their recovery and long afterward.

Psychological Outcomes of Cardiac Arrest Survival

The rates of negative psychological outcomes among cardiac arrest survivors is quite high. Studies reveal that 45 to 50 percent of survivors report symptoms of depression, more than a quarter experience PTSD, and as many as 61 percent experience anxiety.2 Psychological difficulties co-occur in some survivors—specifically, those that report symptoms of PTSD are also likelier to have symptoms of depression and anxiety. These conditions are associated with lower quality of life, and people who also experience cognitive and functional deficits following their cardiac arrest were more likely to struggle with psychological challenges.3

A smaller but important subset of cardiac arrest survivors emerges from the experience with increased psychological resilience, and view it as a positive event in their lives.4 A full understanding of the factors that may predispose patients to follow one mental health trajectory or the other are not well understood. However, one of the main factors in a positive transformational change after cardiac arrest are the ill understood reports of cognitive experiences and a state of painless and non-traumatic visual and auditory awareness of resuscitation.

References

1. Sekhon MS … Griesdale DE. Clinical pathophysiology of hypoxic ischemic brain injury after cardiac arrest: a “two-hit” model. Crit Care. 2017. DOI.
2. Wilder Schaaf KP … Kreutzer JS. Anxiety, depression, and PTSD following cardiac arrest: a systematic review of the literature. Resuscitation. 2012. DOI. Opens in a new tab.
3. Lilja G … Cronberg T. Anxiety and depression among out-of-hospital cardiac arrest survivors. Resuscitation. 2015. DOI. Opens in a new tab.
4. Van Lommel P … Elfferich I. Near-death experience in survivors of cardiac arrest: a prospective study in the Netherlands. Lancet. 2001. DOI. Opens in a new tab.