7 incredible accounts of near death experiences, from speaking to their late grandma to entering a tunnel

• Some cardiac arrest patients have lucid experiences while their heartbeats stop, a study suggests.
• Survivors shared accounts of near death experiences from seeing demons to overwhelming calm.
• Others had memories of the sensation of CPR or their family members saying their name.

People who had near death experiences during cardiac arrest shared what it was like with researchers. Some of their accounts were just like what you see in the movies, while others sounded more like a nightmare.

One cardiac arrest patient told the researchers at NYU Grossman School of Medicine who conducted a study on the subject: "All around me were things like demons and monsters. It felt like they were trying to tear off my body parts."

The authors of the study published in the journal Resuscitation on September 14 defined cardiac arrest as "absent heartbeat and respiration, requiring CPR."

The accounts came from 28 interviews with cardiac arrest survivors, along with testimonies from 126 survivors who self-reported near death experiences. Most participants were from the US or UK.

The aim of the study was to gain a clearer understanding of the range of lucid experiences people can have while in cardiac arrest and undergoing CPR.

The survival rate of a cardiac arrest is low and only 10% were successfully brought back to life, the study said. Of the 28 survivors interviewed, one in four said that despite showing no physical signs of being lucid to the outside world, they had experienced some level of consciousness or dreamlike experience during CPR.

The research teams also measured brain activity in some patients during CPR and found gamma, delta, theta, alpha, and beta waves, which they said suggests some mental function was present.

Dr. Sam Parnia, lead author and an associate professor in the department of medicine at NYU Langone Health, told NBC: "There's nothing more extreme than cardiac arrest because they're literally teetering between life and death, they're in a deep coma and they don't respond to us physically at all.

"What we're able to show is that up to 40% of people actually have a perception of having been conscious to some extent."

Survivors either had some awareness of CPR or a dream-like memory

The themes that emerged from the accounts of patients who had some memories from when their heartbeat was flatlining, were organized into four categories: becoming conscious during CPR, becoming conscious in the post-resuscitation period, having dream/dream-like experiences, and having near death experiences such as seeing deceased loved ones.

The first two mostly entailed people having been aware of something going on around them during CPR, the feeling of something on their chest, or the memory of family members saying their name.

"I could feel someone doing something on my chest. I couldn't feel the actual compressions, but I could feel someone rubbing quite hard. It was quite painful," one participant said.

The dream-like experiences people reported were at times frightening and often involved faceless figures, being pointed at, or being in a random location such as a stranger's home.

Many of the near death experiences reported mirrored how we often see them represented in popular culture. For example, one participant had the sensation of going through a tunnel and experiencing an overwhelming sense of calm and comfort.

"All of my … worries, thoughts, fears, and opinions were gone," they said.

"I was no longer in my body. I floated without weight or physicality. I was above my body and directly below the ceiling of the intensive therapy room," one survivor reported.

Another patient told researchers: "I was asked if I wanted to come home (meaing there) or wanted to come back here. I told them that my two sons needed me and I had to go back. I was suddenly in my body again feeling my achy joints flaring in pain. I really don't remember what was going on around me at that point, just that I hurt."

Another said: "I do remember a being of light … standing near me. It was looming over me like a great tower of strength, yet radiating only warmth and love … I caught glimpses of my life and felt pride, love, joy, and sadness, all pouring into me."

"I thought I heard my grandma [who is dead] saying 'you need to go back,'" one survivor said.

Since CPR was invented in 1960, millions of people have reported near-death experiences, Parnia told CNN. He said that over the last 60 years, many people have reported similar accounts of seeing a God-like figure, viewing their body and surroundings from above, and morally reviewing their lives.