Clinical Takeaway
Cannabis use is associated with an increased risk of atrial arrhythmias, likely driven by the sympathetic stimulation and endothelial dysfunction caused by THC. Clinicians should screen patients with atrial fibrillation or other atrial arrhythmias for cannabis use as part of routine cardiovascular risk assessment. This evidence supports ongoing caution when recommending or approving cannabis use in patients with existing cardiac conditions or arrhythmia risk factors.
#10 Cannabis use and atrial arrhythmias: A systematic review and meta-analysis of large populational studies.
Citation: Chye David M et al.. Cannabis use and atrial arrhythmias: A systematic review and meta-analysis of large populational studies.. Heart rhythm. 2026. PMID: 40472951.
Design: 6 Journal: 0 N: 1 Recency: 3 Pop: 2 Human: 1 Risk: -2
- Preclinical only
Abstract: BACKGROUND: Delta-9-tetrahydrocannabinol, a major component of cannabis, causes sympathetic stimulation and endothelial dysfunction. A recent American Heart Association consensus document has outlined cardiovascular risks associated with cannabis use. However, there are limited data surrounding atrial arrhythmias (AA). OBJECTIVES: This study aimed to investigate the association between cannabis use and the risk of AAs. METHODS: MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched for articles published up to April 2024 for studies on cannabis use and AAs (atrial fibrillation/flutter/tachycardia, supraventricular tachycardia). Odds ratios (OR) and 95% confidence intervals (CIs) were pooled using a random-effects model. The study was prospectively registered (PROSPERO CRD42023428219). RESULTS: Fourteen observational studies were included with 81,230,930 participants from North America, Europe, and Oceania. Mean age was 47.2 years; 63.3% of participants were female. Five studies were prospective. AA was observed in 1.9% of participants (n = 1,578,033), that is, 12.5% of cannabis users (n = 90,195) and 2.7% of controls (n = 1,487,838). Cannabis was associated with a 71% increased risk of AAs (95% CI 1.1-2.6, P = .01). Factors associated with further increased AA risk included concomitant drug use (OR 1.91, 95% CI 1.1-3.5, P = .03) and consumption in cannabis-legal countries (OR 1.93, 95% CI 1.1-3.5, P = .03). CONCLUSION: Cannabis use was associated with a 71% increased risk of AAs. A significant paucity of research in non-Western and teenage populations comprise key areas for future research to better inform public health and legalization policies.
What This Study Teaches Us
Cannabis use is associated with a 71% increased risk of atrial arrhythmias across large observational studies. The association appears stronger when cannabis is used alongside other drugs and in countries where it is legal, though the reasons for these patterns are unclear.
Why This Matters Clinically
Atrial fibrillation and related arrhythmias carry real stroke and heart failure risk. If you counsel patients on cannabis, especially those with cardiac risk factors or those using it recreationally in legal markets, this finding warrants discussion as part of informed decision making.
Study Snapshot
| Study Design | Systematic review and meta-analysis of 14 observational studies |
| Population | 81.2 million participants (mean age 47.2 years, 63.3% female) from North America, Europe, and Oceania. Five studies were prospective cohort studies; the rest cross-sectional or case-control. |
| Intervention | Cannabis use (frequency, dose, and duration not standardized or specified across included studies) |
| Primary Outcome | Atrial fibrillation, atrial flutter, atrial tachycardia, or supraventricular tachycardia |
| Key Result | Cannabis users had 12.5% AA prevalence vs 2.7% in non-users. Pooled OR 1.71 (95% CI 1.1-2.6, P = 0.01) |
Where This Paper Deserves Skepticism
This is fundamentally a pooling of observational studies with substantial heterogeneity in how cannabis exposure and arrhythmias were ascertained and defined. The heavy weighting toward North America and Europe limits generalizability. Most studies were not prospective, so reverse causation and unmeasured confounding (smoking, alcohol, underlying cardiac disease, sympathomimetic co-use) cannot be ruled out. The abstract does not report heterogeneity metrics (I-squared) or sensitivity analyses, which matters when CI spans 1.1 to 2.6. The 12.5% AA rate in cannabis users seems high and raises questions about how cases were identified and whether survivor or detection bias inflated the difference.
Dr. Caplan’s Take
I read this as a signal worth taking seriously, not a smoking gun. The magnitude of increased risk (71% relative increase) is clinically plausible given THC’s sympathomimetic properties, and the consistent direction across multiple studies is reassuring. That said, observational data cannot tell us whether cannabis is causing arrhythmias or whether people at higher arrhythmia risk tend to use cannabis more. In my practice, I counsel cannabis-interested patients with structural heart disease, a personal history of SVT or AFib, or significant comorbidities to discuss this risk with their cardiologist before use, and I screen for palpitations at follow-up visits. For otherwise low-risk patients, this helps inform a conversation but does not constitute a categorical contraindication.
Clinical Bottom Line
Cannabis use was associated with more than a doubling of atrial arrhythmia risk in pooled observational data. Clinicians should ask about cannabis in patients presenting with new palpitations or arrhythmias, and discuss this association when counseling patients with cardiac risk factors.
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