Hi Dear, Welcome to HCM. Understanding your concern. As per your query dizziness and high spikes of heart beat after smoking marijuana is because Marijuana is cannabis and the drug is known to produce intense excitation and may even precipitate psychosis in some individuals. It leads to anxiety symptoms and increase acid secretion. Anxiety can lead to dizziness, increase heart beats and chest pain due to muscle spasm. You have suffered severe palpitations after smoking marijuana and probably this is precipitation of panic attack. Anti anxiety drugs like Beta Blockers especially Propranolol or Atenolol can help to reduce your symptoms of severe palpitations. For relief benzodiazepines can also help if taken on when ever needed basis. Avoid smoking marijuana in future as it may result in severe complications. Hope your concern has been resolved. Best Wishes, Dr. Harry Maheshwari