Heart Jolt Upon Falling Asleep

I have a cyclic issue that continues to plague me and I am at my wits end. It comes and goes, sometimes gone for long periods and sometimes stays for long periods. It's here now.

When I get in bed and fall asleep, the moment as soon as I am asleep, I am JOLTED awake by what I perceive to be a heart attack. I know it's not a heart attack. But,I have the perception that my heart feels like it is completely stopped, I grab my chest to see if my heart is still beating, and my head feels startled and dizzy due to the extreme fear that I am now about to die. Then I calm down, and the process repeats itself on and on on every few minutes. If I am lucky, I finally fall asleep and stay asleep. Sometimes this goes on for hours and hours. I get angry, and have even cried after hours of these jolts and no sleep.

No sweats, no racing heart, no gasping for air. Just a heart-jolt and fear, over and over again. Occasionally I will let out a scream of fear, as some of the jolts are particularity stronger than others. Again, when I finally do get to sleep, I sleep like a baby.

When this issue rears its head, it is also usually accompanied with me being able to hear and feel every heartbeat as I lay in bed. I guess this is a form of palpitations? At work, during the day, no issues with palpitations, very little anxiety/depression anymore. This only happens as soon as I lay down to rest/sleep.

I have changed so much over the past 15 years, cut out caffeine, alcohol, tobacco, all three for long periods of time. I have been on ant depressants, anti anxiety meds, had EKGs, I have had a sleep study and no apnea was identified. This issue seems to follow me despite all of this. Happens during naps, in cars and airplanes, hotels, and at home. I know as soon as it is here, as it has been the past week, it will one day be gone, and then back again.

Any ideas?

Just FYI, I had the same exact problem as yours, it came and went for several years. Have had EKG's come back normal, no sleep apnea either. One day I told my new GP about the problem as well as hot/cold body temp problems which came on recently. He immediately ordered a thyroid test, done from a drawn blood sample. Test results indicated low functioning thyroid and the doctor prescribed daily 50 mcg levothyroxine. Haven't had a problem with either the heart jolting at bedtime or the body temp fluctuations since.

The thyroid hormones regulate heartbeat, body temp, among several other functions. When there's not enough thyroid hormones, the regulatory functions don't work well.

The "jolt" you are describing seems to be a hypnic jerk. Almost everyone experiences them at some point in their lives, but stress can lead to them being more common.

I think you are scaring yourself so much to the point where the stress of them coming actually causes them to occur more often. It is also natural that you will be more aware of your heartbeat if you are really that terrified. Try to relax and remind yourself that nothing bad is going to happen to you as you sleep.