Hi Doctors Discovered A Minor Heart Murmur When I Was

Hi
Doctors discovered a minor heart murmur when I was 10 years old. I DID an echo back thenn and was told that it is really minor I believe it was 0.001% or 0.0001% the valve stays open. I did another echo 2 years later and Was told it was fine and don't have to worry about it. Last year (I was 20 y old) I smoked weed for the first time. Until now, I smoked in total about 3/4 grams maybe less. I smoke once each 3 months or so. Now, I got some weed yesterday but read that weed increases heart beat and therefore with a heart murmur it might cause a heart attack. I never felt a chest pain when I smoked before. But now I'm scarred to smoke :((( I only smoke 0.3 grams in one joint per one day. Would that really put me in a serious risk?!?!