Is it safe for individuals with supraventricular tachycardia (SVT) to use marijuana?

Marijuana and Supraventricular Tachycardia (SVT)

Marijuana use is not recommended for individuals with supraventricular tachycardia (SVT) due to its potential to trigger cardiac arrhythmias and worsen cardiovascular outcomes.

Effects of Marijuana on Cardiac Function

• Cannabis use can cause significant cardiovascular effects including tachycardia immediately after use due to sympathetic nervous system stimulation and parasympathetic nervous system inhibition 1
• Marijuana has been associated with multiple types of arrhythmias including SVT, atrial fibrillation, atrial flutter, and even more serious ventricular arrhythmias 2, 1
• Case reports have documented cannabis-induced SVT that converted to atrial fibrillation, suggesting marijuana can trigger or exacerbate existing supraventricular arrhythmias 2

Risks for SVT Patients

• SVT patients already have a predisposition to tachyarrhythmias, and marijuana's chronotropic effects can potentially trigger or worsen episodes 1
• In patients with underlying cardiac conditions, cannabis use has been associated with more frequent arrhythmias compared to healthy individuals 3
• While SVTs are rarely life-threatening on their own, untreated SVT can result in heart failure, pulmonary edema, and/or myocardial ischemia secondary to increased heart rate 4

Evidence from Clinical Research

• A 2023 study found that patients with ischemic heart disease who used cannabis had a higher prevalence of nonsustained ventricular tachycardia (47.8%) compared to healthy controls (5.6%) 3
• A systematic review identified cannabis use as being associated with increased risk of cardiac dysrhythmias, which while rare, may be life-threatening 1
• Multiple case reports document temporal relationships between marijuana use and the onset of arrhythmias, suggesting a strong association 2, 5, 6

Management Considerations for SVT Patients

• The 2019 ESC guidelines and 2015 ACC/AHA/HRS guidelines for SVT management do not specifically address marijuana use, but focus on established treatments including vagal maneuvers, adenosine, and cardioversion for acute management 4, 7
• Beta-blockers are recommended for acute management of narrow-QRS tachycardias and AVRT, and these medications may help mitigate some of the tachycardic effects of marijuana if exposure occurs 4, 7
• For patients with recurrent SVT, catheter ablation is the most effective therapy to prevent recurrence, with success rates of 94.3-98.5% 7

Recommendations for SVT Patients

• SVT patients should be advised to avoid marijuana use due to its potential to trigger arrhythmias 1
• Patients who continue to use marijuana should be educated about warning signs that require immediate medical attention, including palpitations, chest pain, dizziness, or syncope 2, 1
• Clinicians should specifically inquire about acute and chronic cannabis use in patients presenting with tachycardia, dysrhythmia, chest pain, and/or unexplained syncope 1

Special Considerations

• The risk of marijuana-induced arrhythmias appears to be higher in patients with structural heart disease or pre-existing cardiovascular conditions 3, 5
• The combination of marijuana with other substances (alcohol, tobacco, stimulants) may further increase arrhythmia risk 2
• Patients using marijuana medicinally for other conditions should discuss alternative treatments with their healthcare provider if they have SVT 1