August 1, 2026Journal of the American College of Cardiology
Acute Effects of Cannabis Inhalation on Cardiac Ectopy, Physical Activity, Sleep, and Glucose
Key result
Inhaled cannabis reduces daily cardiac ectopy by ~9% compared to abstinence.
- RR 0.91
- 95% CI 0.85-0.98
- P=0.02
- n=108
Journal of the American College of Cardiology published a graphical abstract
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Why the study?
Data regarding cardiovascular effects of inhaled cannabis are conflicting and generally arise from observational studies, necessitating controlled evaluation of acute effects on cardiac ectopy.
Key Points
- To evaluate the acute cardiovascular and metabolic effects of cannabis inhalation, specifically assessing cardiac ectopy, glucose levels, physical activity, and sleep duration.
- Prospective, randomized, crossover trial (MARY-JANE; NCT06021613) enrolling N=108 habitual cannabis users (mean age 32 ± 10 years, 59% women) without known arrhythmias.
- Participants were randomly assigned daily via text message to inhale or abstain from cannabis over 14 days, with adherence tracked using ECG patch button presses, daily surveys, and salivary mass spectrometry.
- Inhaled cannabis resulted in a significant 9% reduction in total daily ectopic beats compared to abstinence (RR: 0.91; 95% CI: 0.85-0.98; P = 0.02).
- Daily premature atrial contractions fell by 10% on inhalation days (RR: 0.90; 95% CI: 0.82-0.97; P = 0.012), whereas premature ventricular contractions showed no significant change.
- Each cannabis inhalation episode correlated with a 2% decline in ectopic beats (RR: 0.98; 95% CI: 0.97-0.99; P = 0.043), with no significant differences observed in step counts, sleep duration, or glucose levels.
Study Design
Type
RCT (n=108)
Randomization
Crossover
PICO
P
Population
108 adults (mean age 32, 59% women) who regularly smoke or vape cannabis and have no history of cardiac arrhythmias, assessed in a 14-day crossover trial.
I
Intervention / Comparator
Inhaled cannabis vs Abstinence
O
Primary Outcome
Daily cardiac ectopy (daily premature atrial contractions and premature ventricular contractions) — RR 0.91 (0.85-0.98), p=0.02
Main Result
Relative Risk: 0.91 (95% CI 0.85–0.98)
p-value: p=0.02
Limitations
- Potential withdrawal effects
- Moderate adherence
- Co-intervention
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“This study examined the acute effects of cannabis in people who use it regularly and was not designed to evaluate the long-term health consequences. The overall health effects of inhaled cannabis may still be net negative, but these findings suggest there may be something about cannabis that can teach us more about the biological mechanisms that produce premature atrial contractions.”
“Those early heartbeats are common in the general population, and we now recognize that more of them can lead to important forms of heart disease. Healthy people who regularly used cannabis experienced 'significantly less abnormal, early heart beats' when they smoked or vaped cannabis in the trial, compared to days they were told to avoid all cannabis.”
“We were surprised by the results because they contradicted our original hypothesis. That's why randomized trials are so important. When the data challenge our expectations, our job as scientists is to understand them, not ignore them.”
Implication
Randomized crossover trial reveals cannabis inhalation reduces daily premature atrial contractions in habitual users, indicating acute electrophysiological effects.
Abstract
BACKGROUND Inhaled cannabis is widely legal in the United States. Data regarding cardiovascular effects are conflicting and generally arise from observational studies. OBJECTIVES The goal was to evaluate the acute effects of cannabis inhalation on cardiac ectopy. METHODS We conducted a prospective, randomized, crossover trial to assess effects of inhaled cannabis on cardiac ectopy, mean glucose levels, step counts, and sleep durations. Adults who smoked or vaped cannabis on a regular basis without a history of cardiac arrhythmias were enrolled. Participants were randomly assigned each day to inhale vs abstain from cannabis via text messages for 14 days. Adherence was assessed using time-stamped Zio patch button presses at the time of cannabis use, daily surveys, and, in a subset, salivary mass spectrometry. The primary outcome was daily cardiac ectopy (daily premature atrial contractions and premature ventricular contractions). RESULTS Of 108 participants (mean age 32 ± 10 years, 59% women, and 37% non-Hispanic White) experiencing a total of 713 days randomized to inhaled cannabis and 616 days randomized to abstinence, randomization adherence was imperfect but generally supportive of assignment adherence. Inhaled cannabis resulted in a statistically significant 9% reduction in ectopic beats (rate ratio [RR]: 0.91; 95% CI: 0.85-0.98; P = 0.02). Daily premature atrial contractions decreased by 10% (RR: 0.90; 95% CI: 0.82-0.97; P = 0.012), whereas premature ventricular contractions showed no significant change. Each cannabis inhalation was associated with a 2% reduction in ectopic beats (RR: 0.98; 95% CI: 0.97-0.99; P = 0.043). No significant differences were observed for step counts, sleep duration, or glucose levels. CONCLUSIONS In a pragmatic crossover design including habitual cannabis users, randomization to inhaled cannabis was associated with less cardiac ectopy, driven by fewer premature atrial contractions. Potential withdrawal effects, moderate adherence, and co-intervention limit interpretation of causal mechanism. (Marijuana and Acute Risk of Arrhythmia-Joint Abstinence and Exposure [MARY-JANE]; NCT06021613).
Discussion
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Cite This Study
Elias et al. (2026) conducted an RCT in Habitual cannabis use (n=108). Inhaled cannabis vs. Abstinence was evaluated on Daily cardiac ectopy (daily premature atrial contractions and premature ventricular contractions) (RR 0.91, 95% CI 0.85-0.98, p=0.02). Inhaled cannabis was associated with a 9% reduction in daily cardiac ectopy compared to abstinence (RR 0.91; 95% CI 0.85-0.98; P=0.02).