Relationship between vitamin D deficiency and success of cardioversion in patients with atrial fibrillation.

Background: Inflammation plays an important role in the pathogenesis of atrial fibrillation (AF). Vitamin D deficiency has been found to increase vulnerability to AF. The authors aimed to determine the relationship between vitamin D deficiency and cardioversion success in AF patients.

Methods: The study included 200 persistent AF patients presenting for cardioversion. Serum vitamin D level was sampled on admission. The success of cardioversion was assessed and patients divided into two groups: successful or failed (group I and II, respectively). Vitamin D level was assessed and patients were divided into three groups: deficient, insufficient, and sufficient vitamin D level. Cardioversion was performed pharmacologically or electrically. Failure of cardioversion was defined as: (1) detection of AF rhythm in 12-lead ECG recording immediately after cardioversion or within 6‑month follow-up, or (2) ECG Holter monitoring of AF lasting > 30 s at 6‑month follow-up.

Results: There was a highly statistically significant difference in baseline serum vitamin D level between group I and group II (P-value < 0.01). There were no statistically significant differences between the three groups in terms of vitamin D levels regarding age, gender, body mass index, smoking, and left atrial diameter.

Conclusion: This study demonstrated that AF cardioversion failure was associated with vitamin D deficiency in patients without structural heart disease, while sufficient and insufficient vitamin D levels were associated with successful cardioversion. Therefore, vitamin D level assessment before cardioversion may help predict the success of cardioversion, and possible correction of deficient vitamin D levels may increase the chance of successful cardioversion.