In some cultures in the Northern Hemisphere, the astronomical March equinox (varying between 19 and 21 March) is taken to mark the first day of spring, and the Northern solstice (around 21 June) is taken as the first day of summer. In other traditions, the equinox is taken as mid-spring.
Circulation problems that cause dizziness. You may feel dizzy, faint or off balance if your heart isn't pumping enough blood to your brain. Causes include: 1  Drop in blood pressure.
Conditions that can trigger sudden cardiac arrest include: â¢ Coronary artery disease. This is the most common cause of sudden cardiac arrest in people older than 35. â¢ Cardiomyopathy. When you have this condition, your heart muscle becomes enlarged or thick, so it's weakened. â¢ Long QT syndrome and Brugada syndrome. These disorders of the heartâs electrical system can cause abnormal heart rhythms.