Smoking and Cardisiography-Derived Spatial QRS–T Angle in Adults Without Known Cardiovascular Disease

Objective: Smoking has been associated with conventional electrocardiographic alterations, but its relationship with directly acquired three-dimensional vectorcardiographic measurements remains unclear. This study investigated the association between current smoking and the Cardisiography-derived spatial QRS–T angle in adults without known cardiovascular disease.
Method: This retrospective study included adults without known cardiovascular disease who underwent 12-lead ECG and Cardisiography between January 2023 and December 2025. Current smokers reported regular cigarette use for at least 1 year, whereas never-smokers served as controls. The primary endpoint was the spatial QRS–T angle. Secondary endpoints included QRS and T vector angles, T magnitude, heart rate, QRS duration, and PR, QRS, QT, and QTc intervals. Group comparisons were supplemented by multivariable linear regression adjusted for age, sex, and body mass index.
Results: Among 212 participants, 113 were never-smokers and 99 were current smokers. The spatial QRS–T angle did not differ between the groups (38.0° [18.0–89.0] vs 29.7° [18.0–85.7]; p=.61) and was not associated with current smoking after adjustment (β=2.04°, 95% CI, −12.16 to 16.24; p=.78). Adjusted QRS duration was longer in current smokers (β=7.29 ms, 95% CI, 3.60–10.98; p<.001); no other vectorcardiographic or ECG parameter showed a significant adjusted association.
Conclusion: Current smoking was not associated with Cardisiography-derived vectorcardiographic parameters after adjustment. The longer QRS duration, an exploratory secondary finding, may reflect altered ventricular activation timing without a detectable change in the depolarization–repolarization vector relationship. To our knowledge, this is the first study to relate smoking to directly acquired spatial vectorcardiographic measurements.

Keywords: Electrocardiography, QRS-T angle, smoking, vectorcardiography.