Aims: There is some clinical evidence of the association between vitamin B12 deficiency and vasovagal syncope (VVS) in pediatric patients. We aimed to investigate the possible association of vitamin B12 and folate deficiency with VVS in adults. Methods: In this case-control study, we included adult patients with VVS who presented to our tertiary syncope unit for a head-up tilt table test as the case group. We selected age- and sex-matched individuals without any history of syncope from the population-based Tehran Cohort Study as the control group. The exclusion criteria included but were not restricted to taking vitamin B supplements, carbamazepine, or phenobarbital, and sleeve gastrectomy. We measured and compared serum levels of vitamin B12, folate, and homocysteine. Results: From February 2020 to February 2021, we included 44 patients in the case group, matched with 44 controls, with a mean age of 37.9 years and 23 (52.3%) females in each group. There was no statistically significant difference between the study groups regarding vitamin B12 or folate deficiency, or their serum levels. The serum level of vitamin B12 was remarkably lower in patients with frequent VVS (≥3 lifetime episodes) compared to patients with infrequent VVS (<3 lifetime episodes) [233.8 (80.7) versus 305.2 (118.1) pg/mL; P=0.042] and this association remained significant after adjustment for possible confounders (P=0.026). Conclusion: We found no association between vitamin B12 or folate deficiency, or their serum levels and VVS; nevertheless, frequent VVS, compared to infrequent VVS, was associated with a lower serum vitamin B12.

Introduction Although several studies are available regarding baseline Electrocardiographic (ECG) parameters, major and minor ECG abnormalities, there is a big controversy regarding their age and gender differences in literature, thus we aimed to investigate any possible age or gender ECG discrepancies in general adult population. Methods Data of 7630 adults aged ≥35 years from Tehran Cohort Study who were registered between March 2016 to March 2019 were collected. ECG basic values, major, and minor ECG abnormalities-defined according to the Minnesota Code-were analyzed and compared between genders, and four distinct age groups. Odds ratio of having any major ECG abnormality between males, and females stratified by age, and number of cardiovascular risk factors was calculated. Results ECG information of 7630 participants was available. The average age was 53.6 (±12.66), and women made up 54.2% (n=4132) of subjects. The average heart rate (HR) was higher among women(p<0.0001), while the average values of QRS duration, P wave duration, and RR intervals were higher among men(p<0.0001). Major ECG abnormalities were observed in 2.9% of study population (with right bundle branch block, left bundle branch block, and Atrial Fibrillation being the most common) and were more prevalent among men compared to women (3.1% vs 2.7% p=0.188). Moreover, minor abnormalities were observed in 25.9% of study population, and again were more prevalent among men (36.4% vs 17% p<0.001). Prevalence of major ECG abnormalities was significantly higher in participants older than 65 years old, and participants who had ≥3 conventional cardiovascular (CV) risk factors. Conclusion Basic ECG values is different in male and female general population. In addition, major and minor ECG abnormalities were roughly more prevalent in male subjects. In both genders, odds of having major ECG abnormalities surges with increase in number of conventional CV risk factors and age.