Believe it or not, how you sleep affects your heart. According to the Heart Foundation, there is research that links poor sleep to heart disease. A very interesting American study found a correlation between the changing time in fall and spring and heart attacks. "Falling" back saw a reduction in heart attacks a few days after the change, and "springing" forward saw and increase. Studies in different countries have found similar findings. Although research is not exactly sure why too little sleep is bad, they theorize that it is because it's associated with high blood pressure and increased inflammation. Sleep apnea is strongly associated with heart disease and studies also link insomnia with increased risk of heart disease.
So how much sleep is best for the heart? There is bit of debate over this, but 7 hours is usually considered optimal.