HOME >> BIOLOGY >> NEWS
Your heart is being closely watched while you're asleep

IF YOU thought sleep is when you really relax, think again. Scientists have discovered that the heart comes under especially close control during sleep. Their findings suggest that sleep may play a role that until now has remained hidden.

Scientists now know that the heartbeat is far more complex and irregular than once supposed (New Scientist, 3 January 1998, p 20). The signals that control a healthy heartbeat contain many different frequency components, and this leads to a highly complex pattern of intervals between beats.

The gaps between heartbeats are "anti-correlated": if the heart speeds up over a short sequence of beats, it will slow down again over the next few beats. More importantly, the pattern of these speed-up/slow-down events can be seen on both short and long timescales: it looks the same over a few beats as it does for a thousand beats. In other words, the heartbeat has a fractal pattern.

An international team led by Plamen Ivanov of the physics department at Boston University decided to compare how the fluctuations in the interval between beats varied between day and night. The results surprised them: during the supposedly relaxed state of sleep, the intervals between heartbeats fluctuated much more strongly, but were brought under control more quickly, showing that the heart is under much closer control during sleep. "It was totally counterintuitive," says Ivanov.

The team initially thought the difference might come about because the body is resting during sleep. Physical activity tends to cause changes in the heartbeat, which would lead to more fluctuations and give the appearance that the heart had less control. But a marked difference remained even when these external influences were taken into account.

The researchers then compared their results with heart data from the cos-monauts on Mir. "It was interesting to compare them with the cosmonauts who were doing something different under different conditions," says L
'"/>

Contact: Claire Bowles
claire.bowles@rbi.co.uk
44-0-20-7331-2751
New Scientist
30-Nov-1999


Page: 1 2

Related biology news :

1. Preclinical safety study shows adipose-derived stem cells improve heart function after heart attack
2. Screen siblings, parents of infants with severe heart abnormalities
3. Recent evolution at a single gene may have brought down heart disease risk in some human groups
4. How do you mend a broken heart?
5. Protemix corporation announces discovery of way to repair hearts damaged by diabetes
6. Embryonic stem cell therapy shows steady benefits in rebuilding infarcted heart
7. Putting energy into heart protection
8. Rare mutations can significantly increase risk factor for heart disease
9. Smart gene therapy protects against damage from heart attack
10. University of Pittsburgh medical center among first to implant heart assist device
11. Reading hexametric rhyme supports cardiac synchronization, especially after a heart attack

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/21/2016)... 21, 2016 NuData Security announced today that ... of principal product architect and that Jon ... customer development. Both will report directly to ... moves reflect NuData,s strategic growth in its product ... customer demand and customer focus values. ...
(Date:6/16/2016)... , June 16, 2016 ... is expected to reach USD 1.83 billion by ... View Research, Inc. Technological proliferation and increasing demand ... are expected to drive the market growth. ... The development of advanced multimodal techniques ...
(Date:6/9/2016)... -- Perkotek an innovation leader in attendance control systems is proud to announce the introduction ... to make sure the right employees are actually signing in, and to even control ... ... ... ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... 2016 , ... Newly created 4Sight Medical Solutions ... healthcare market. The company's primary focus is on new product introductions, to include ... are necessary to help companies efficiently bring their products to market. , The ...
(Date:6/27/2016)... , June 27, 2016  Liquid Biotech ... announced the funding of a Sponsored Research Agreement ... circulating tumor cells (CTCs) from cancer patients.  The ... in CTC levels correlate with clinical outcomes in ... These data will then be employed to support ...
(Date:6/24/2016)... June 24, 2016  Regular discussions on a range of ... between the two entities said Poloz. Speaking at ... Ottawa , he pointed to the country,s inflation target, ... government. "In certain ... institutions have common economic goals, why not sit down and ...
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers and fluorometers ... the 6000i models are higher end machines that use the more unconventional z-dimension of ... beam from the bottom of the cuvette holder. , FireflySci has developed several ...
Breaking Biology Technology:
Cached News: