Abstract

Electronic cigarettes (E-cigs) are commonly presumed as a safer alternative to traditional cigarettes despite limited understanding of their health risks. This assumption may lead people, especially those in at-risk groups, to switch from traditional cigarettes to e-cigs, or to use e-cigs as their first form of nicotine consumption. Despite that pregnancy increases susceptibility to adverse cardiac events, a considerable fraction of pregnant women use e-cigs during gestation and postpartum. Pregnancy involves profound physiologic changes that increase risk for developing cardiac arrhythmias-disruptions in the normal rhythm of the heart that can promote ventricular fibrillation, cardiomyopathy, and sudden cardiac death. Additionally, studies have shown that e-cig aerosols can induce sympathetic nervous system dominance and evoke arrhythmias in mice. We posited that e-cig exposure during pregnancy destabilizes maternal cardiac autonomic modulation and induces ventricular arrhythmias. Using radiotelemetry, we found that gestational e-cig exposure accentuates pregnancy-associated sympathetic dominance and increases ventricular premature beats (VPBs) during the parturition period. Additionally, at three weeks postpartum (three weeks after exposure cessation), e-cig-exposed dams have more VPBs, shortened ventricular repolarization, and increased ejection fraction. Therefore, e-cig use during gestation promotes sympathetic dominance and ventricular arrhythmias during parturition. Importantly, these arrhythmias persist up to three weeks after cessation of exposure and parturition and are accompanied by accelerated repolarization and enhanced left ventricular systolic function consistent with sympathetic dominance. Thus, vaping during pregnancy may increase the incidence of peripartum arrhythmias, with these effects persisting well after e-cig cessation and accompanied by enhanced ventricular repolarization and systole.