New research published in the European Heart Journal has shown that stimulation of the brain during deep sleep leads to improved cardiac output and relaxation of the left ventricle, leading to improved cardiovascular function.
The randomized, controlled, cross-over study included 18 healthy adult males ages 30–57. On three non-consecutive nights, the participants went to a sleep lab where their brain activity, blood pressure, and heart activity were monitored during sleep. On two of the three nights, the participants’ brains were stimulated during deep sleep via brief auditory tones designed to stimulate slow wave sleep. The goal of the study was to determine whether auditory enhancement of slow waves affects cardiovascular function during and after sleep.
The results showed that enhancement of sleep slow waves led to better function of the heart’s left ventricle via more vigorous contractions and relaxations. This led to more efficient pumping of blood throughout the body and more blood entering the circulatory system. Overall, this effect causes greater cardiovascular function.
One of the authors of the study noted that they were surprised by the clear and measurable effects of the stimulation after only one night of sleep. The impact of slow wave stimulation on the heart’s ability to pump blood could be useful for both cardiologists and athletes. Cardiovascular disease could be treated or prevented in some patients via the improved cardiovascular function caused by deep sleep stimulation. Deep sleep stimulation of athletes could also potentially be used to recovery more fully and more quickly after intense workouts. However, more research is required before deep sleep stimulation should be used on patients and athletes, including a larger sample and the inclusion of women.
Sources: European Heart Journal, Science Daily