Our body has Carcadian system and this rythm dips and raises throutout the day. This system sends out PA1-1 cells which blocks the blood clots from breaking down. Another reason is when we wake up, brain floods the heart with hormones which increases the load on the heart .
Chest pain, shortness of breathe, dizziness, sweating, palpitations.
Warning sings of heart blockage are chest pain(may not always in the chest, it could be in the shoulder,arm,jaw) palpitations, dizziness, nausea, shortness of breathe.
There is nothing as such. You can drink water at any time of the day.