Hi, Thanks for posting in HCM. I understand your concern. Smoking weed (Marijuana) releases the main psychoactive chemical tetrahydrocannabinol (THC), which is absorbed into the bloodstream via the lungs. It alters the chemicals in the brain and nervous system, which could cause vasoconstriction and alterations in the functioning of the heart. Hence it can eventually increase blood pressure and heart rate, which can manifest as heart palpitations. In such circumstances, it would be advisable to discontinue its use or to take it at a lower concentrations which would not produce such effects. Hope the information provided would be helpful. All the best.