E-cigarettes and their lone constituents induce cardiac arrhythmia and conduction defects in mice

• Published in: Nature communications Vol. 13; no. 1; pp. 6088 - 16
• Main Authors: Carll, Alex P., Arab, Claudia, Salatini, Renata, Miles, Meredith D., Nystoriak, Matthew A., Fulghum, Kyle L., Riggs, Daniel W., Shirk, Gregg A., Theis, Whitney S., Talebi, Nima, Bhatnagar, Aruni, Conklin, Daniel J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25.10.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 13/100; 631/443/592/75/29/1938; 64/60; 692/4019/592/75/29; 692/499; 9/25; 9/30; Acrolein; Acrolein - toxicity; Aerosols; Animals; Arrhythmia; Arrhythmias, Cardiac - chemically induced; Autonomic nervous system; Bradycardia; Byproducts; Cardiac arrhythmia; Chemical composition; Cigarette smoke; Cigarettes; Conduction; Constituents; Electrocardiography; Electronic cigarettes; Electronic Nicotine Delivery Systems; Electrophysiology; Exposure; Female; Glycerol; Heart rate; Humanities and Social Sciences; Inhalation; Long-term effects; Menthol; Mice; Modulation; multidisciplinary; Nicotiana; Nicotine; Parasympathetic nervous system; Propylene; Propylene Glycol; Reflexes; Respiration; Science; Science (multidisciplinary); Smoking; Solvents; Tobacco; Variability; Vegetables; Ventricle
• DOI: 10.1038/s41467-022-33203-1
• ISSN: 2041-1723

E-cigarette use has surged, but the long-term health effects remain unknown. E-cigarette aerosols containing nicotine and acrolein, a combustion and e-cigarette byproduct, may impair cardiac electrophysiology through autonomic imbalance. Here we show in mouse electrocardiograms that acute inhalation of e-cigarette aerosols disturbs cardiac conduction, in part through parasympathetic modulation. We demonstrate that, similar to acrolein or combustible cigarette smoke, aerosols from e-cigarette solvents (vegetable glycerin and propylene glycol) induce bradycardia, bradyarrhythmias, and elevations in heart rate variability during inhalation exposure, with inverse post-exposure effects. These effects are slighter with tobacco- or menthol-flavored aerosols containing nicotine, and in female mice. Yet, menthol-flavored and PG aerosols also increase ventricular arrhythmias and augment early ventricular repolarization (J amplitude), while menthol uniquely alters atrial and atrioventricular conduction. Exposure to e-cigarette aerosols from vegetable glycerin and its byproduct, acrolein, diminish heart rate and early repolarization. The pro-arrhythmic effects of solvent aerosols on ventricular repolarization and heart rate variability depend partly on parasympathetic modulation, whereas ventricular arrhythmias positively associate with early repolarization dependent on the presence of nicotine. Our study indicates that chemical constituents of e-cigarettes could contribute to cardiac risk by provoking pro-arrhythmic changes and stimulating autonomic reflexes. The use of E-cigarettes has increased despite the unknown long-term effects. Here the authors show that e-cigarette aerosols alter cardiac conduction, repolarization, and autonomic regulation in mice, contingent on the chemical composition of e-liquids and partly through parasympathetic modulation.