Adverse Cardiac Effects of Ultrasonic Vaping Devices Despite Lack of Heating Coil

Abstract Introduction Ultrasonic vaping devices like SURGE are marketed as safer alternatives to conventional coil-based electronic cigarettes like JUUL due to their lower operating temperatures. However, their impact on cardiovascular health has not been fully characterized. Methods Sprague–Dawley rats were exposed daily for 9 weeks to aerosol generated from SURGE, JUUL, or clean air. Heart rate variability (HRV) was continuously monitored via implanted telemetry. Cardiac fibrosis was quantified using histological analysis. Temperature profiles of SURGE, JUUL, and Nautilus (a coil-based tank device) were recorded. Aerosol samples were analyzed for carbonyl compounds using high-performance liquid chromatography. Results Both SURGE and JUUL exposures significantly reduced HRV (high frequency and total power) compared to air. JUUL exposure significantly increased cardiac fibrosis; SURGE showed a similar mean fibrosis level but greater variability, resulting in a nonsignificant difference. SURGE devices operated at lower peak temperatures (~131°C) than JUUL (~239°C) and Nautilus (~160–170°C). Despite it having the lowest temperature, SURGE emitted higher levels of carbonyl compounds than JUUL, although still substantially lower than Nautilus. Conclusions Although SURGE operates without coils and at lower temperatures than coiled vaping devices, it generates higher levels of carbonyls than some coiled devices and impairs cardiac autonomic regulation, and it can cause cardiac fibrosis comparable to JUUL although with high variability; that is, SURGE does not reliably avoid the increase in fibrosis caused by conventional e-cigarettes. These findings suggest that non-thermal mechanisms predominate in mediating cardiovascular toxicity associated with ultrasonic vaping, challenging the assumption that coil-free designs are inherently safer. Implications Despite its lower operating temperature and coil-free design, the SURGE ultrasonic vaping device impaired cardiac autonomic function and promoted fibrosis at a mean level comparable to that of JUUL. These findings challenge claims of reduced harm from coil-less vaping technologies and suggest that non-thermal mechanisms may drive toxicity. Regulatory evaluations should consider device emissions and physiological outcomes—not just hardware features. Physicians and policymakers should be aware that coil-less systems may still pose cardiovascular risks, and marketing these devices as inherently safer may mislead users and undermine tobacco harm reduction efforts.