Background: The relationship between self-reported and urinary cotinine-verified smoking status and atrial arrhythmia (AA) is unclear. The aim of this study was to evaluate the association of self-reported and urine cotinine-verified smoking status with AA.Method: A total of 201,788 participants (106,375 men, mean age 37 years) who had both a urinary cotinine measurement and electrocardiogram were included. Cotinine-verified current smoking was defined as a urinary cotinine level above 50 ng/mL. Individuals were divided into three groups based on self-reported smoking and two groups based on cotinineverified smoking status. Results: Among overall subjects, 505 had documented AA (0.3%) and 135 had atrial fibrillation (AF) (0.1%). Self-reported current smoking was associated with an increased risk of AA (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.06–1.91; p = 0.019) and AF (OR, 2.20; 95% CI, 1.24–3.90; p = 0.007), whereas self-reported former smoking had no significant association with AA (OR, 1.30; 95% CI, 0.97–1.73; p = 0.078) and AF (OR, 1.74; 95% CI, 1.00–3.04; p = 0.051). Cotinine-verified current smoking showed no significant association with AA (OR, 1.24; 95% CI, 0.98–1.58; p = 0.080) and AF (OR, 1.20; 95% CI, 0.79–1.83; p = 0.391). Conclusion Self-reported current smoking was associated with AA and AF, while selfreported former smoking and cotinine-verified current smoking showed no significant association with AA and AF.

PURPOSE: "Chest compression-only" CPR encourages CPR by untrained lay people. Guidelines do not include victim's chest exposure, which might result in inaccurate compression point; therefore, this study compares accuracy of lay rescuer's chest compression point in dressed and undressed situations. METHODS: In this prospective observational cross-over study conducted in a simulation center of a tertiary academic hospital in the Republic of Korea, 96 non-medical college student volunteers were asked to point in random order to the location of four reference chest compression points [inter-nipple line (INL), center of the chest (CoC), lower quarter of the sternum (LQS), and lower end of the sternum (LES)]. In dressed and undressed situations, length from sternal notch to each of the subject-recognized compression and reference points and degree of deviation from sternum midline was compared. RESULTS: In both dressed and undressed situations, INL was closest while LQS, CoC, and LES were further away, in said order, from the sternal notch. The undressed situation showed association with lower reference and subjectrecognized chest compression point differences; subjectrecognized chest compression point deviation; and out-ofchest compression point frequency. CONCLUSION: Addition of "exposing victim's chest" to the CPR education program for untrained lay people might facilitate accurate and safe localization of chest compression points in cardiac arrest patients.
Cardiopulmonary Resuscitation* ; Cross-Over Studies ; Education ; Heart Arrest ; Humans ; Prospective Studies ; Republic of Korea ; Sternum ; Thorax* ; Volunteers