Premature Birth clinical trials at UCSF

Despite recreational cannabis now being legal in 23 states, where more than 100 million Americans reside, studies on the actual health effects are limited. This study is a randomized trial, where each participant will be instructed to consume or avoid cannabis on randomly assigned days during a 14-day monitoring period. The goal of this study is to answer the question: "Does cannabis use increase the frequency of 'early' and abnormal heart beats?" During the 14-day period, participants will wear an external heart monitor, a glucose monitor, and a fitness tracker to track heart rhythm, glucose levels, step counts, and sleep health. Participants will use a mobile app or a text messaging service for daily instructions/reminders on cannabis use, and short surveys. The investigators ask that participants smoke or vape cannabis at least once on days they are instructed to consume cannabis. Compelling evidence of heart and other health effects would be important to the clinical care of our patients.

Premature atrial contractions (PACs) and premature ventricular contractions (PVCs) are observed in the majority of individuals monitored for more than a few hours. Although the clinical course of PACs and PVCs is usually benign, it has been described that high PAC or PVC frequency causes various comorbidities and worsens outcomes in different patient groups. For example, PACs can initiate episodes of atrial fibrillation, and PAC count is highly specific in predicting diagnosis of incident atrial fibrillation. Increasing PVC frequencies are an important predictor of incident heart failure. While conventional wisdom dictates that common environmental exposures determine PAC and PVC frequencies, this has not born out in rigorous studies. Whether PAC and PVC frequencies may have genetic underpinnings remains unknown. Comparisons between identical twins and fraternal twins can provide estimates of heritability. Fraternal twins are an ideal control because, like identical twins, they share a womb, have the same birthday, and their environment while growing up are as similar as between identical twins. However, while identical twins share approximately 100% of the same inherited DNA, fraternal twins share, on average, about 50%. By monitoring identical and fraternal twins with portable electrocardiograms (ECGs), we will be able to count the PACs and PVCs over a consecutive timespan to describe the familial aggregation of these complexes. This, to our knowledge, would be the first study to compare PAC and PVC frequencies in identical and same-sex fraternal twins, providing the first assessment of how genetical inheritance may influence cardiac ectopy burdens.