Hi there ~
I understand your concerns. Yes, smoking
marijuana is dangerous in your condition of having a congenital AV heart block
which needed you to have a two lead pacemaker implanted. Also alcohol should not be used in your condition. I believe that you will have long term and serious side effects from the use of marijuana and advise you strongly to quit the substance. If you have problems in quitting due to withdrawals and urges and cravings, I advise you to consult a psychiatrist
who can help with the situation. I wish you the very best in your recovery.
I hope this helps. Take care and have a lovely day!