Talk to General Physician on Fainting Spell

Asslam o Alaikum

Sir Yesterday while I was in standing position for about 10 minutes, I felt discomfort in my chest (heart) with a desire to sit down. But I waited as my friend was talking to me. Then I did not remembered anything. After approximately 3 minutes when I got my senses back, I was laid down on ground and my friend was trying to help me get my senses. I was having sweats on my forehead.

My friend told me that I had got a fainting spell. Afterward I am all well. No pain no weakness. No issue at all except Drop down of blood pressure upto 10 points. Kindly guide me what had caused this fainting spell. Is there any cardiac issue.